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gerrit-public.fairphone.software / platform / external / llvm / 15565ad758ae28f21a1f8bbcc92fac49482bd820 / . / docs / LangRef.html
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5 <title>LLVM Assembly Language Reference Manual</title>
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7 <meta name="author" content="Chris Lattner">
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]8 <meta name="description"
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]14
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]15<h1>LLVM Language Reference Manual</h1>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]27 <li><a href="#linkage_linker_private_weak">'<tt>linker_private_weak</tt>' Linkage</a></li>
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]28 <li><a href="#linkage_linker_private_weak_def_auto">'<tt>linker_private_weak_def_auto</tt>' Linkage</a></li>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]29 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
30 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
31 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
32 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
33 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
34 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
35 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
Chris Lattner5a2d8752009-10-10 18:26:06 +0000[diff] [blame]36 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]37 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
38 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
39 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
40 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]41 </ol>
42 </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]43 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]44 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]45 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]46 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]47 <li><a href="#aliasstructure">Aliases</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]48 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]49 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]50 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]51 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]52 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]53 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]54 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]55 <li><a href="#volatile">Volatile Memory Accesses</a></li>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]56 <li><a href="#memmodel">Memory Model for Concurrent Operations</a></li>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]57 <li><a href="#ordering">Atomic Memory Ordering Constraints</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]58 </ol>
59 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]60 <li><a href="#typesystem">Type System</a>
61 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]62 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]63 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]64 <ol>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]65 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]66 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]67 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]68 <li><a href="#t_void">Void Type</a></li>
69 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]70 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]71 </ol>
72 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]73 <li><a href="#t_derived">Derived Types</a>
74 <ol>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]75 <li><a href="#t_aggregate">Aggregate Types</a>
76 <ol>
77 <li><a href="#t_array">Array Type</a></li>
78 <li><a href="#t_struct">Structure Type</a></li>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]79 <li><a href="#t_opaque">Opaque Structure Types</a></li>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]80 <li><a href="#t_vector">Vector Type</a></li>
81 </ol>
82 </li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]83 <li><a href="#t_function">Function Type</a></li>
84 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]85 </ol>
86 </li>
87 </ol>
88 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]89 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]90 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]91 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]92 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]93 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
94 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]95 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]96 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]97 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]98 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]99 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]100 <li><a href="#othervalues">Other Values</a>
101 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]102 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]103 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]104 </ol>
105 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]106 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
107 <ol>
108 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]109 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
110 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]111 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
112 Global Variable</a></li>
113 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
114 Global Variable</a></li>
115 </ol>
116 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]117 <li><a href="#instref">Instruction Reference</a>
118 <ol>
119 <li><a href="#terminators">Terminator Instructions</a>
120 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]121 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
122 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]123 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]124 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]125 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]126 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]127 <li><a href="#i_resume">'<tt>resume</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]128 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]129 </ol>
130 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]131 <li><a href="#binaryops">Binary Operations</a>
132 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]133 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]134 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]135 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]136 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]137 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]138 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]139 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
140 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
141 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]142 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
143 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
144 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]145 </ol>
146 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]147 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
148 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]149 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
150 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
151 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]152 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]153 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]154 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]155 </ol>
156 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]157 <li><a href="#vectorops">Vector Operations</a>
158 <ol>
159 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
160 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
161 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]162 </ol>
163 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]164 <li><a href="#aggregateops">Aggregate Operations</a>
165 <ol>
166 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
167 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
168 </ol>
169 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]170 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]171 <ol>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]172 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
173 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
174 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
175 <li><a href="#i_fence">'<tt>fence</tt>' Instruction</a></li>
176 <li><a href="#i_cmpxchg">'<tt>cmpxchg</tt>' Instruction</a></li>
177 <li><a href="#i_atomicrmw">'<tt>atomicrmw</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]178 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]179 </ol>
180 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]181 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]182 <ol>
183 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
184 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
185 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
186 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
187 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]188 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
189 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
190 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
191 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]192 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
193 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]194 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]195 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]196 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]197 <li><a href="#otherops">Other Operations</a>
198 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]199 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
200 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]201 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]202 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]203 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]204 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]205 <li><a href="#i_landingpad">'<tt>landingpad</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]206 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]207 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]208 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]209 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]210 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]211 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]212 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
213 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]214 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
215 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
216 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]217 </ol>
218 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]219 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
220 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]221 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
222 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
223 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]224 </ol>
225 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]226 <li><a href="#int_codegen">Code Generator Intrinsics</a>
227 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]228 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
229 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
230 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
231 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
232 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
233 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohman31f1af12010-05-26 21:56:15 +0000[diff] [blame]234 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]235 </ol>
236 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]237 <li><a href="#int_libc">Standard C Library Intrinsics</a>
238 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]239 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
240 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
241 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
242 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
243 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]244 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
245 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
246 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohman08b280b2011-05-27 00:36:31 +0000[diff] [blame]247 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
248 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]249 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]250 </ol>
251 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]252 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]253 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]254 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]255 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
256 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
257 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]258 </ol>
259 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]260 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
261 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]262 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
263 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
264 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
265 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
266 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]267 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]268 </ol>
269 </li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]270 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
271 <ol>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]272 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
273 <li><a href="#int_convert_from_fp16">'<tt>llvm.convert.from.fp16</tt>' Intrinsic</a></li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]274 </ol>
275 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]276 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]277 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]278 <li><a href="#int_trampoline">Trampoline Intrinsics</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]279 <ol>
280 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]281 <li><a href="#int_at">'<tt>llvm.adjust.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]282 </ol>
283 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]284 <li><a href="#int_atomics">Atomic intrinsics</a>
285 <ol>
286 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
287 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
288 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
289 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
290 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
291 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
292 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
293 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
294 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
295 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
296 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
297 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
298 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
299 </ol>
300 </li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]301 <li><a href="#int_memorymarkers">Memory Use Markers</a>
302 <ol>
303 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
304 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
305 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
306 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
307 </ol>
308 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]309 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]310 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]311 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]312 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]313 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]314 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]315 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]316 '<tt>llvm.trap</tt>' Intrinsic</a></li>
317 <li><a href="#int_stackprotector">
318 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]319 <li><a href="#int_objectsize">
320 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]321 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]322 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]323 </ol>
324 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]325</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]326
327<div class="doc_author">
328 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
329 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]330</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]331
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]332<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]333<h2><a name="abstract">Abstract</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]334<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]335
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]336<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]337
338<p>This document is a reference manual for the LLVM assembly language. LLVM is
339 a Static Single Assignment (SSA) based representation that provides type
340 safety, low-level operations, flexibility, and the capability of representing
341 'all' high-level languages cleanly. It is the common code representation
342 used throughout all phases of the LLVM compilation strategy.</p>
343
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]344</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]345
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]346<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]347<h2><a name="introduction">Introduction</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]348<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]349
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]350<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]351
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]352<p>The LLVM code representation is designed to be used in three different forms:
353 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
354 for fast loading by a Just-In-Time compiler), and as a human readable
355 assembly language representation. This allows LLVM to provide a powerful
356 intermediate representation for efficient compiler transformations and
357 analysis, while providing a natural means to debug and visualize the
358 transformations. The three different forms of LLVM are all equivalent. This
359 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]360
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]361<p>The LLVM representation aims to be light-weight and low-level while being
362 expressive, typed, and extensible at the same time. It aims to be a
363 "universal IR" of sorts, by being at a low enough level that high-level ideas
364 may be cleanly mapped to it (similar to how microprocessors are "universal
365 IR's", allowing many source languages to be mapped to them). By providing
366 type information, LLVM can be used as the target of optimizations: for
367 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]368 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]369 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]370
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]371<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]372<h4>
373 <a name="wellformed">Well-Formedness</a>
374</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]375
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]376<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]377
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]378<p>It is important to note that this document describes 'well formed' LLVM
379 assembly language. There is a difference between what the parser accepts and
380 what is considered 'well formed'. For example, the following instruction is
381 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]382
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]383<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]384%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]385</pre>
386
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]387<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
388 LLVM infrastructure provides a verification pass that may be used to verify
389 that an LLVM module is well formed. This pass is automatically run by the
390 parser after parsing input assembly and by the optimizer before it outputs
391 bitcode. The violations pointed out by the verifier pass indicate bugs in
392 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]393
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]394</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]395
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]396</div>
397
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]398<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]399
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]400<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]401<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]402<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]403
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]404<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]405
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]406<p>LLVM identifiers come in two basic types: global and local. Global
407 identifiers (functions, global variables) begin with the <tt>'@'</tt>
408 character. Local identifiers (register names, types) begin with
409 the <tt>'%'</tt> character. Additionally, there are three different formats
410 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]411
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]412<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]413 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]414 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
415 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
416 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
417 other characters in their names can be surrounded with quotes. Special
418 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
419 ASCII code for the character in hexadecimal. In this way, any character
420 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]421
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]422 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]423 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]424
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]425 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]426 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]427</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]428
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]429<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]430 don't need to worry about name clashes with reserved words, and the set of
431 reserved words may be expanded in the future without penalty. Additionally,
432 unnamed identifiers allow a compiler to quickly come up with a temporary
433 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]434
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]435<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]436 languages. There are keywords for different opcodes
437 ('<tt><a href="#i_add">add</a></tt>',
438 '<tt><a href="#i_bitcast">bitcast</a></tt>',
439 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
440 ('<tt><a href="#t_void">void</a></tt>',
441 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
442 reserved words cannot conflict with variable names, because none of them
443 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]444
445<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]446 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]447
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]448<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]449
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]450<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]451%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]452</pre>
453
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]454<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]455
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]456<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]457%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]458</pre>
459
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]460<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]461
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]462<pre class="doc_code">
Gabor Greifec58f752009-10-28 13:05:07 +0000[diff] [blame]463%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
464%1 = <a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]465%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]466</pre>
467
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]468<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
469 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]470
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]471<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]472 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]473 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]474
475 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]476 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]477
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]478 <li>Unnamed temporaries are numbered sequentially</li>
479</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]480
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]481<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]482 demonstrating instructions, we will follow an instruction with a comment that
483 defines the type and name of value produced. Comments are shown in italic
484 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]485
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]486</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]487
488<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]489<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]490<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]491<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]492<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]493<h3>
494 <a name="modulestructure">Module Structure</a>
495</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]496
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]497<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]498
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]499<p>LLVM programs are composed of "Module"s, each of which is a translation unit
500 of the input programs. Each module consists of functions, global variables,
501 and symbol table entries. Modules may be combined together with the LLVM
502 linker, which merges function (and global variable) definitions, resolves
503 forward declarations, and merges symbol table entries. Here is an example of
504 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]505
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]506<pre class="doc_code">
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]507<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckydb9cd762011-01-29 01:09:53 +0000[diff] [blame]508<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a>&nbsp;<a href="#globalvars">constant</a>&nbsp;<a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]509
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]510<i>; External declaration of the puts function</i>&nbsp;
511<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]512
513<i>; Definition of main function</i>
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]514define i32 @main() { <i>; i32()* </i>&nbsp;
515 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
516 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8*</i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]517
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]518 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
519 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
520 <a href="#i_ret">ret</a> i32 0&nbsp;
521}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]522
523<i>; Named metadata</i>
524!1 = metadata !{i32 41}
525!foo = !{!1, null}
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]526</pre>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]527
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]528<p>This example is made up of a <a href="#globalvars">global variable</a> named
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]529 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]530 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]531 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
532 "<tt>foo"</tt>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]533
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]534<p>In general, a module is made up of a list of global values, where both
535 functions and global variables are global values. Global values are
536 represented by a pointer to a memory location (in this case, a pointer to an
537 array of char, and a pointer to a function), and have one of the
538 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]539
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]540</div>
541
542<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]543<h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]544 <a name="linkage">Linkage Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]545</h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]546
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]547<div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]548
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]549<p>All Global Variables and Functions have one of the following types of
550 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]551
552<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]553 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]554 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
555 by objects in the current module. In particular, linking code into a
556 module with an private global value may cause the private to be renamed as
557 necessary to avoid collisions. Because the symbol is private to the
558 module, all references can be updated. This doesn't show up in any symbol
559 table in the object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]560
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]561 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]562 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
563 assembler and evaluated by the linker. Unlike normal strong symbols, they
564 are removed by the linker from the final linked image (executable or
565 dynamic library).</dd>
566
567 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
568 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
569 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
570 linker. The symbols are removed by the linker from the final linked image
571 (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]572
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]573 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
574 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
575 of the object is not taken. For instance, functions that had an inline
576 definition, but the compiler decided not to inline it. Note,
577 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
578 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
579 visibility. The symbols are removed by the linker from the final linked
580 image (executable or dynamic library).</dd>
581
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]582 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling07d31772010-06-29 22:34:52 +0000[diff] [blame]583 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]584 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
585 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]586
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]587 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]588 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]589 into the object file corresponding to the LLVM module. They exist to
590 allow inlining and other optimizations to take place given knowledge of
591 the definition of the global, which is known to be somewhere outside the
592 module. Globals with <tt>available_externally</tt> linkage are allowed to
593 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
594 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]595
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]596 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]597 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]598 the same name when linkage occurs. This can be used to implement
599 some forms of inline functions, templates, or other code which must be
600 generated in each translation unit that uses it, but where the body may
601 be overridden with a more definitive definition later. Unreferenced
602 <tt>linkonce</tt> globals are allowed to be discarded. Note that
603 <tt>linkonce</tt> linkage does not actually allow the optimizer to
604 inline the body of this function into callers because it doesn't know if
605 this definition of the function is the definitive definition within the
606 program or whether it will be overridden by a stronger definition.
607 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
608 linkage.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]609
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]610 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]611 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
612 <tt>linkonce</tt> linkage, except that unreferenced globals with
613 <tt>weak</tt> linkage may not be discarded. This is used for globals that
614 are declared "weak" in C source code.</dd>
615
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]616 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]617 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
618 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
619 global scope.
620 Symbols with "<tt>common</tt>" linkage are merged in the same way as
621 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]622 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]623 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]624 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
625 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]626
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]627
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]628 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]629 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]630 pointer to array type. When two global variables with appending linkage
631 are linked together, the two global arrays are appended together. This is
632 the LLVM, typesafe, equivalent of having the system linker append together
633 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]634
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]635 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]636 <dd>The semantics of this linkage follow the ELF object file model: the symbol
637 is weak until linked, if not linked, the symbol becomes null instead of
638 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]639
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]640 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
641 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]642 <dd>Some languages allow differing globals to be merged, such as two functions
643 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]644 that only equivalent globals are ever merged (the "one definition rule"
645 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]646 and <tt>weak_odr</tt> linkage types to indicate that the global will only
647 be merged with equivalent globals. These linkage types are otherwise the
648 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]649
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]650 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]651 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]652 visible, meaning that it participates in linkage and can be used to
653 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]654</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]655
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]656<p>The next two types of linkage are targeted for Microsoft Windows platform
657 only. They are designed to support importing (exporting) symbols from (to)
658 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]659
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]660<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]661 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]662 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]663 or variable via a global pointer to a pointer that is set up by the DLL
664 exporting the symbol. On Microsoft Windows targets, the pointer name is
665 formed by combining <code>__imp_</code> and the function or variable
666 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]667
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]668 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]669 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]670 pointer to a pointer in a DLL, so that it can be referenced with the
671 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
672 name is formed by combining <code>__imp_</code> and the function or
673 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]674</dl>
675
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]676<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
677 another module defined a "<tt>.LC0</tt>" variable and was linked with this
678 one, one of the two would be renamed, preventing a collision. Since
679 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
680 declarations), they are accessible outside of the current module.</p>
681
682<p>It is illegal for a function <i>declaration</i> to have any linkage type
683 other than "externally visible", <tt>dllimport</tt>
684 or <tt>extern_weak</tt>.</p>
685
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]686<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]687 or <tt>weak_odr</tt> linkages.</p>
688
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]689</div>
690
691<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]692<h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]693 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]694</h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]695
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]696<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]697
698<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]699 and <a href="#i_invoke">invokes</a> can all have an optional calling
700 convention specified for the call. The calling convention of any pair of
701 dynamic caller/callee must match, or the behavior of the program is
702 undefined. The following calling conventions are supported by LLVM, and more
703 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]704
705<dl>
706 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]707 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]708 specified) matches the target C calling conventions. This calling
709 convention supports varargs function calls and tolerates some mismatch in
710 the declared prototype and implemented declaration of the function (as
711 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]712
713 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]714 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]715 (e.g. by passing things in registers). This calling convention allows the
716 target to use whatever tricks it wants to produce fast code for the
717 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]718 (Application Binary Interface).
719 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]720 when this or the GHC convention is used.</a> This calling convention
721 does not support varargs and requires the prototype of all callees to
722 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]723
724 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]725 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]726 as possible under the assumption that the call is not commonly executed.
727 As such, these calls often preserve all registers so that the call does
728 not break any live ranges in the caller side. This calling convention
729 does not support varargs and requires the prototype of all callees to
730 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]731
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]732 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
733 <dd>This calling convention has been implemented specifically for use by the
734 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
735 It passes everything in registers, going to extremes to achieve this by
736 disabling callee save registers. This calling convention should not be
737 used lightly but only for specific situations such as an alternative to
738 the <em>register pinning</em> performance technique often used when
739 implementing functional programming languages.At the moment only X86
740 supports this convention and it has the following limitations:
741 <ul>
742 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
743 floating point types are supported.</li>
744 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
745 6 floating point parameters.</li>
746 </ul>
747 This calling convention supports
748 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
749 requires both the caller and callee are using it.
750 </dd>
751
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]752 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]753 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]754 target-specific calling conventions to be used. Target specific calling
755 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]756</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]757
758<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]759 support Pascal conventions or any other well-known target-independent
760 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]761
762</div>
763
764<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]765<h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]766 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]767</h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]768
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]769<div>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]770
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]771<p>All Global Variables and Functions have one of the following visibility
772 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]773
774<dl>
775 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]776 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]777 that the declaration is visible to other modules and, in shared libraries,
778 means that the declared entity may be overridden. On Darwin, default
779 visibility means that the declaration is visible to other modules. Default
780 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]781
782 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]783 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]784 object if they are in the same shared object. Usually, hidden visibility
785 indicates that the symbol will not be placed into the dynamic symbol
786 table, so no other module (executable or shared library) can reference it
787 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]788
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]789 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]790 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]791 the dynamic symbol table, but that references within the defining module
792 will bind to the local symbol. That is, the symbol cannot be overridden by
793 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]794</dl>
795
796</div>
797
798<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]799<h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]800 <a name="namedtypes">Named Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]801</h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]802
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]803<div>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]804
805<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]806 it easier to read the IR and make the IR more condensed (particularly when
807 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]808
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]809<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]810%mytype = type { %mytype*, i32 }
811</pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]812
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]813<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattnerdc65f222010-08-17 23:26:04 +0000[diff] [blame]814 "<a href="#t_void">void</a>". Type name aliases may be used anywhere a type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]815 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]816
817<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]818 and that you can therefore specify multiple names for the same type. This
819 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
820 uses structural typing, the name is not part of the type. When printing out
821 LLVM IR, the printer will pick <em>one name</em> to render all types of a
822 particular shape. This means that if you have code where two different
823 source types end up having the same LLVM type, that the dumper will sometimes
824 print the "wrong" or unexpected type. This is an important design point and
825 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]826
827</div>
828
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]829<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]830<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]831 <a name="globalvars">Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]832</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]833
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]834<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]835
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]836<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]837 instead of run-time. Global variables may optionally be initialized, may
838 have an explicit section to be placed in, and may have an optional explicit
839 alignment specified. A variable may be defined as "thread_local", which
840 means that it will not be shared by threads (each thread will have a
841 separated copy of the variable). A variable may be defined as a global
842 "constant," which indicates that the contents of the variable
843 will <b>never</b> be modified (enabling better optimization, allowing the
844 global data to be placed in the read-only section of an executable, etc).
845 Note that variables that need runtime initialization cannot be marked
846 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]847
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]848<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
849 constant, even if the final definition of the global is not. This capability
850 can be used to enable slightly better optimization of the program, but
851 requires the language definition to guarantee that optimizations based on the
852 'constantness' are valid for the translation units that do not include the
853 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]854
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]855<p>As SSA values, global variables define pointer values that are in scope
856 (i.e. they dominate) all basic blocks in the program. Global variables
857 always define a pointer to their "content" type because they describe a
858 region of memory, and all memory objects in LLVM are accessed through
859 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]860
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]861<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
862 that the address is not significant, only the content. Constants marked
Rafael Espindolaa5eaa862011-01-15 08:20:57 +0000[diff] [blame]863 like this can be merged with other constants if they have the same
864 initializer. Note that a constant with significant address <em>can</em>
865 be merged with a <tt>unnamed_addr</tt> constant, the result being a
866 constant whose address is significant.</p>
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]867
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]868<p>A global variable may be declared to reside in a target-specific numbered
869 address space. For targets that support them, address spaces may affect how
870 optimizations are performed and/or what target instructions are used to
871 access the variable. The default address space is zero. The address space
872 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]873
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]874<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]875 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]876
Chris Lattnerce99fa92010-04-28 00:13:42 +0000[diff] [blame]877<p>An explicit alignment may be specified for a global, which must be a power
878 of 2. If not present, or if the alignment is set to zero, the alignment of
879 the global is set by the target to whatever it feels convenient. If an
880 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner2d4b8ee2010-04-28 00:31:12 +0000[diff] [blame]881 alignment. Targets and optimizers are not allowed to over-align the global
882 if the global has an assigned section. In this case, the extra alignment
883 could be observable: for example, code could assume that the globals are
884 densely packed in their section and try to iterate over them as an array,
885 alignment padding would break this iteration.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]886
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]887<p>For example, the following defines a global in a numbered address space with
888 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]889
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]890<pre class="doc_code">
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]891@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]892</pre>
893
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]894</div>
895
896
897<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]898<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]899 <a name="functionstructure">Functions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]900</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]901
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]902<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]903
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]904<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]905 optional <a href="#linkage">linkage type</a>, an optional
906 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]907 <a href="#callingconv">calling convention</a>,
908 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]909 <a href="#paramattrs">parameter attribute</a> for the return type, a function
910 name, a (possibly empty) argument list (each with optional
911 <a href="#paramattrs">parameter attributes</a>), optional
912 <a href="#fnattrs">function attributes</a>, an optional section, an optional
913 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
914 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]915
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]916<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
917 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]918 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]919 <a href="#callingconv">calling convention</a>,
920 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]921 <a href="#paramattrs">parameter attribute</a> for the return type, a function
922 name, a possibly empty list of arguments, an optional alignment, and an
923 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]924
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]925<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]926 (Control Flow Graph) for the function. Each basic block may optionally start
927 with a label (giving the basic block a symbol table entry), contains a list
928 of instructions, and ends with a <a href="#terminators">terminator</a>
929 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]930
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]931<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]932 executed on entrance to the function, and it is not allowed to have
933 predecessor basic blocks (i.e. there can not be any branches to the entry
934 block of a function). Because the block can have no predecessors, it also
935 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]936
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]937<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]938 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]939
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]940<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]941 the alignment is set to zero, the alignment of the function is set by the
942 target to whatever it feels convenient. If an explicit alignment is
943 specified, the function is forced to have at least that much alignment. All
944 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]945
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]946<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
947 be significant and two identical functions can be merged</p>.
948
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]949<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]950<pre class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]951define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]952 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
953 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
954 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
955 [<a href="#gc">gc</a>] { ... }
956</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]957
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]958</div>
959
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]960<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]961<h3>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]962 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]963</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]964
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]965<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]966
967<p>Aliases act as "second name" for the aliasee value (which can be either
968 function, global variable, another alias or bitcast of global value). Aliases
969 may have an optional <a href="#linkage">linkage type</a>, and an
970 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]971
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]972<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]973<pre class="doc_code">
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]974@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]975</pre>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]976
977</div>
978
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]979<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]980<h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]981 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]982</h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]983
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]984<div>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]985
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]986<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]987 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]988 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]989
990<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]991<pre class="doc_code">
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]992; Some unnamed metadata nodes, which are referenced by the named metadata.
993!0 = metadata !{metadata !"zero"}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]994!1 = metadata !{metadata !"one"}
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]995!2 = metadata !{metadata !"two"}
Dan Gohman1005bc52010-07-13 19:48:13 +0000[diff] [blame]996; A named metadata.
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]997!name = !{!0, !1, !2}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]998</pre>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]999
1000</div>
1001
1002<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1003<h3>
1004 <a name="paramattrs">Parameter Attributes</a>
1005</h3>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1006
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1007<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1008
1009<p>The return type and each parameter of a function type may have a set of
1010 <i>parameter attributes</i> associated with them. Parameter attributes are
1011 used to communicate additional information about the result or parameters of
1012 a function. Parameter attributes are considered to be part of the function,
1013 not of the function type, so functions with different parameter attributes
1014 can have the same function type.</p>
1015
1016<p>Parameter attributes are simple keywords that follow the type specified. If
1017 multiple parameter attributes are needed, they are space separated. For
1018 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1019
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1020<pre class="doc_code">
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]1021declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]1022declare i32 @atoi(i8 zeroext)
1023declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1024</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1025
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1026<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1027 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1028
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1029<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1030
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1031<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1032 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1033 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichebe81732011-03-16 22:20:18 +0000[diff] [blame]1034 should be zero-extended to the extent required by the target's ABI (which
1035 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1036 parameter) or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1037
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1038 <dt><tt><b>signext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1039 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich9e69ff92011-03-17 14:21:58 +0000[diff] [blame]1040 should be sign-extended to the extent required by the target's ABI (which
1041 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1042 return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1043
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1044 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1045 <dd>This indicates that this parameter or return value should be treated in a
1046 special target-dependent fashion during while emitting code for a function
1047 call or return (usually, by putting it in a register as opposed to memory,
1048 though some targets use it to distinguish between two different kinds of
1049 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1050
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1051 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1052 <dd><p>This indicates that the pointer parameter should really be passed by
1053 value to the function. The attribute implies that a hidden copy of the
1054 pointee
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1055 is made between the caller and the callee, so the callee is unable to
1056 modify the value in the callee. This attribute is only valid on LLVM
1057 pointer arguments. It is generally used to pass structs and arrays by
1058 value, but is also valid on pointers to scalars. The copy is considered
1059 to belong to the caller not the callee (for example,
1060 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1061 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1062 values.</p>
1063
1064 <p>The byval attribute also supports specifying an alignment with
1065 the align attribute. It indicates the alignment of the stack slot to
1066 form and the known alignment of the pointer specified to the call site. If
1067 the alignment is not specified, then the code generator makes a
1068 target-specific assumption.</p></dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1069
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1070 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1071 <dd>This indicates that the pointer parameter specifies the address of a
1072 structure that is the return value of the function in the source program.
1073 This pointer must be guaranteed by the caller to be valid: loads and
1074 stores to the structure may be assumed by the callee to not to trap. This
1075 may only be applied to the first parameter. This is not a valid attribute
1076 for return values. </dd>
1077
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1078 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1079 <dd>This indicates that pointer values
1080 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmanefca7f92010-07-02 23:46:54 +0000[diff] [blame]1081 value do not alias pointer values which are not <i>based</i> on it,
1082 ignoring certain "irrelevant" dependencies.
1083 For a call to the parent function, dependencies between memory
1084 references from before or after the call and from those during the call
1085 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1086 return value used in that call.
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1087 The caller shares the responsibility with the callee for ensuring that
1088 these requirements are met.
1089 For further details, please see the discussion of the NoAlias response in
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1090 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1091<br>
John McCall191d4ee2010-07-06 21:07:14 +0000[diff] [blame]1092 Note that this definition of <tt>noalias</tt> is intentionally
1093 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner211244a2010-07-06 20:51:35 +0000[diff] [blame]1094 arguments, though it is slightly weaker.
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1095<br>
1096 For function return values, C99's <tt>restrict</tt> is not meaningful,
1097 while LLVM's <tt>noalias</tt> is.
1098 </dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1099
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1100 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1101 <dd>This indicates that the callee does not make any copies of the pointer
1102 that outlive the callee itself. This is not a valid attribute for return
1103 values.</dd>
1104
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1105 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1106 <dd>This indicates that the pointer parameter can be excised using the
1107 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1108 attribute for return values.</dd>
1109</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1110
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1111</div>
1112
1113<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1114<h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1115 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1116</h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1117
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1118<div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1119
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1120<p>Each function may specify a garbage collector name, which is simply a
1121 string:</p>
1122
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1123<pre class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1124define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1125</pre>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1126
1127<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1128 collector which will cause the compiler to alter its output in order to
1129 support the named garbage collection algorithm.</p>
1130
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1131</div>
1132
1133<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1134<h3>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1135 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1136</h3>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1137
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1138<div>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1139
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1140<p>Function attributes are set to communicate additional information about a
1141 function. Function attributes are considered to be part of the function, not
1142 of the function type, so functions with different parameter attributes can
1143 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1144
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1145<p>Function attributes are simple keywords that follow the type specified. If
1146 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1147
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1148<pre class="doc_code">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1149define void @f() noinline { ... }
1150define void @f() alwaysinline { ... }
1151define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1152define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1153</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1154
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1155<dl>
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1156 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1157 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1158 the backend should forcibly align the stack pointer. Specify the
1159 desired alignment, which must be a power of two, in parentheses.
1160
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1161 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1162 <dd>This attribute indicates that the inliner should attempt to inline this
1163 function into callers whenever possible, ignoring any active inlining size
1164 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1165
Dan Gohman129bd562011-06-16 16:03:13 +0000[diff] [blame]1166 <dt><tt><b>nonlazybind</b></tt></dt>
1167 <dd>This attribute suppresses lazy symbol binding for the function. This
1168 may make calls to the function faster, at the cost of extra program
1169 startup time if the function is not called during program startup.</dd>
1170
Jakob Stoklund Olesen570a4a52010-02-06 01:16:28 +0000[diff] [blame]1171 <dt><tt><b>inlinehint</b></tt></dt>
1172 <dd>This attribute indicates that the source code contained a hint that inlining
1173 this function is desirable (such as the "inline" keyword in C/C++). It
1174 is just a hint; it imposes no requirements on the inliner.</dd>
1175
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1176 <dt><tt><b>naked</b></tt></dt>
1177 <dd>This attribute disables prologue / epilogue emission for the function.
1178 This can have very system-specific consequences.</dd>
1179
1180 <dt><tt><b>noimplicitfloat</b></tt></dt>
1181 <dd>This attributes disables implicit floating point instructions.</dd>
1182
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1183 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1184 <dd>This attribute indicates that the inliner should never inline this
1185 function in any situation. This attribute may not be used together with
1186 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1187
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1188 <dt><tt><b>noredzone</b></tt></dt>
1189 <dd>This attribute indicates that the code generator should not use a red
1190 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1191
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1192 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1193 <dd>This function attribute indicates that the function never returns
1194 normally. This produces undefined behavior at runtime if the function
1195 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1196
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1197 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1198 <dd>This function attribute indicates that the function never returns with an
1199 unwind or exceptional control flow. If the function does unwind, its
1200 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1201
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1202 <dt><tt><b>optsize</b></tt></dt>
1203 <dd>This attribute suggests that optimization passes and code generator passes
1204 make choices that keep the code size of this function low, and otherwise
1205 do optimizations specifically to reduce code size.</dd>
1206
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1207 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1208 <dd>This attribute indicates that the function computes its result (or decides
1209 to unwind an exception) based strictly on its arguments, without
1210 dereferencing any pointer arguments or otherwise accessing any mutable
1211 state (e.g. memory, control registers, etc) visible to caller functions.
1212 It does not write through any pointer arguments
1213 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1214 changes any state visible to callers. This means that it cannot unwind
1215 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1216 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1217
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1218 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1219 <dd>This attribute indicates that the function does not write through any
1220 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1221 arguments) or otherwise modify any state (e.g. memory, control registers,
1222 etc) visible to caller functions. It may dereference pointer arguments
1223 and read state that may be set in the caller. A readonly function always
1224 returns the same value (or unwinds an exception identically) when called
1225 with the same set of arguments and global state. It cannot unwind an
1226 exception by calling the <tt>C++</tt> exception throwing methods, but may
1227 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1228
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1229 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1230 <dd>This attribute indicates that the function should emit a stack smashing
1231 protector. It is in the form of a "canary"&mdash;a random value placed on
1232 the stack before the local variables that's checked upon return from the
1233 function to see if it has been overwritten. A heuristic is used to
1234 determine if a function needs stack protectors or not.<br>
1235<br>
1236 If a function that has an <tt>ssp</tt> attribute is inlined into a
1237 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1238 function will have an <tt>ssp</tt> attribute.</dd>
1239
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1240 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1241 <dd>This attribute indicates that the function should <em>always</em> emit a
1242 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1243 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1244<br>
1245 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1246 function that doesn't have an <tt>sspreq</tt> attribute or which has
1247 an <tt>ssp</tt> attribute, then the resulting function will have
1248 an <tt>sspreq</tt> attribute.</dd>
Rafael Espindolafbff0ec2011-07-25 15:27:59 +0000[diff] [blame]1249
1250 <dt><tt><b><a name="uwtable">uwtable</a></b></tt></dt>
1251 <dd>This attribute indicates that the ABI being targeted requires that
1252 an unwind table entry be produce for this function even if we can
1253 show that no exceptions passes by it. This is normally the case for
1254 the ELF x86-64 abi, but it can be disabled for some compilation
1255 units.</dd>
1256
Rafael Espindola25456ef2011-10-03 14:45:37 +0000[diff] [blame]1257 <dt><tt><b><a name="returns_twice">returns_twice</a></b></tt></dt>
1258 <dd>This attribute indicates that this function can return
1259 twice. The C <code>setjmp</code> is an example of such a function.
1260 The compiler disables some optimizations (like tail calls) in the caller of
1261 these functions.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1262</dl>
1263
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1264</div>
1265
1266<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1267<h3>
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1268 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1269</h3>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1270
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1271<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1272
1273<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1274 the GCC "file scope inline asm" blocks. These blocks are internally
1275 concatenated by LLVM and treated as a single unit, but may be separated in
1276 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1277
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1278<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1279module asm "inline asm code goes here"
1280module asm "more can go here"
1281</pre>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1282
1283<p>The strings can contain any character by escaping non-printable characters.
1284 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1285 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1286
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1287<p>The inline asm code is simply printed to the machine code .s file when
1288 assembly code is generated.</p>
1289
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1290</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1291
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1292<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1293<h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1294 <a name="datalayout">Data Layout</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1295</h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1296
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1297<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1298
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1299<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1300 data is to be laid out in memory. The syntax for the data layout is
1301 simply:</p>
1302
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1303<pre class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1304target datalayout = "<i>layout specification</i>"
1305</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1306
1307<p>The <i>layout specification</i> consists of a list of specifications
1308 separated by the minus sign character ('-'). Each specification starts with
1309 a letter and may include other information after the letter to define some
1310 aspect of the data layout. The specifications accepted are as follows:</p>
1311
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1312<dl>
1313 <dt><tt>E</tt></dt>
1314 <dd>Specifies that the target lays out data in big-endian form. That is, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1315 bits with the most significance have the lowest address location.</dd>
1316
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1317 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1318 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1319 the bits with the least significance have the lowest address
1320 location.</dd>
1321
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1322 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1323 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1324 <i>preferred</i> alignments. All sizes are in bits. Specifying
1325 the <i>pref</i> alignment is optional. If omitted, the
1326 preceding <tt>:</tt> should be omitted too.</dd>
1327
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1328 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1329 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1330 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1331
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1332 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1333 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1334 <i>size</i>.</dd>
1335
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1336 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1337 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesen9d8d2212010-05-28 18:54:47 +0000[diff] [blame]1338 <i>size</i>. Only values of <i>size</i> that are supported by the target
1339 will work. 32 (float) and 64 (double) are supported on all targets;
1340 80 or 128 (different flavors of long double) are also supported on some
1341 targets.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1342
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1343 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1344 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1345 <i>size</i>.</dd>
1346
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1347 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1348 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1349 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1350
1351 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1352 <dd>This specifies a set of native integer widths for the target CPU
1353 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1354 "n32:64" for PowerPC 64, or "n8:16:32:64" for X86-64. Elements of
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1355 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1356 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1357</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1358
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1359<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]1360 default set of specifications which are then (possibly) overridden by the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1361 specifications in the <tt>datalayout</tt> keyword. The default specifications
1362 are given in this list:</p>
1363
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1364<ul>
1365 <li><tt>E</tt> - big endian</li>
Dan Gohmanfdf2e8c2010-02-23 02:44:03 +0000[diff] [blame]1366 <li><tt>p:64:64:64</tt> - 64-bit pointers with 64-bit alignment</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1367 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1368 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1369 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1370 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1371 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1372 alignment of 64-bits</li>
1373 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1374 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1375 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1376 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1377 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1378 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1379</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1380
1381<p>When LLVM is determining the alignment for a given type, it uses the
1382 following rules:</p>
1383
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1384<ol>
1385 <li>If the type sought is an exact match for one of the specifications, that
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1386 specification is used.</li>
1387
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1388 <li>If no match is found, and the type sought is an integer type, then the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1389 smallest integer type that is larger than the bitwidth of the sought type
1390 is used. If none of the specifications are larger than the bitwidth then
1391 the the largest integer type is used. For example, given the default
1392 specifications above, the i7 type will use the alignment of i8 (next
1393 largest) while both i65 and i256 will use the alignment of i64 (largest
1394 specified).</li>
1395
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1396 <li>If no match is found, and the type sought is a vector type, then the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1397 largest vector type that is smaller than the sought vector type will be
1398 used as a fall back. This happens because &lt;128 x double&gt; can be
1399 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1400</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1401
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1402</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1403
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1404<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1405<h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1406 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1407</h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1408
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1409<div>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1410
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1411<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1412with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1413is undefined. Pointer values are associated with address ranges
1414according to the following rules:</p>
1415
1416<ul>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1417 <li>A pointer value is associated with the addresses associated with
1418 any value it is <i>based</i> on.
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1419 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1420 range of the variable's storage.</li>
1421 <li>The result value of an allocation instruction is associated with
1422 the address range of the allocated storage.</li>
1423 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1424 no address.</li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1425 <li>An integer constant other than zero or a pointer value returned
1426 from a function not defined within LLVM may be associated with address
1427 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1428 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1429 allocated by mechanisms provided by LLVM.</li>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1430</ul>
1431
1432<p>A pointer value is <i>based</i> on another pointer value according
1433 to the following rules:</p>
1434
1435<ul>
1436 <li>A pointer value formed from a
1437 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1438 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1439 <li>The result value of a
1440 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1441 of the <tt>bitcast</tt>.</li>
1442 <li>A pointer value formed by an
1443 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1444 pointer values that contribute (directly or indirectly) to the
1445 computation of the pointer's value.</li>
1446 <li>The "<i>based</i> on" relationship is transitive.</li>
1447</ul>
1448
1449<p>Note that this definition of <i>"based"</i> is intentionally
1450 similar to the definition of <i>"based"</i> in C99, though it is
1451 slightly weaker.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1452
1453<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1454<tt><a href="#i_load">load</a></tt> merely indicates the size and
1455alignment of the memory from which to load, as well as the
Dan Gohmanc22c0f32010-06-17 19:23:50 +0000[diff] [blame]1456interpretation of the value. The first operand type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1457<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1458and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1459
1460<p>Consequently, type-based alias analysis, aka TBAA, aka
1461<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1462LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1463additional information which specialized optimization passes may use
1464to implement type-based alias analysis.</p>
1465
1466</div>
1467
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1468<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1469<h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1470 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1471</h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1472
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1473<div>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1474
1475<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1476href="#i_store"><tt>store</tt></a>s, and <a
1477href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1478The optimizers must not change the number of volatile operations or change their
1479order of execution relative to other volatile operations. The optimizers
1480<i>may</i> change the order of volatile operations relative to non-volatile
1481operations. This is not Java's "volatile" and has no cross-thread
1482synchronization behavior.</p>
1483
1484</div>
1485
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1486<!-- ======================================================================= -->
1487<h3>
1488 <a name="memmodel">Memory Model for Concurrent Operations</a>
1489</h3>
1490
1491<div>
1492
1493<p>The LLVM IR does not define any way to start parallel threads of execution
1494or to register signal handlers. Nonetheless, there are platform-specific
1495ways to create them, and we define LLVM IR's behavior in their presence. This
1496model is inspired by the C++0x memory model.</p>
1497
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1498<p>For a more informal introduction to this model, see the
1499<a href="Atomics.html">LLVM Atomic Instructions and Concurrency Guide</a>.
1500
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1501<p>We define a <i>happens-before</i> partial order as the least partial order
1502that</p>
1503<ul>
1504 <li>Is a superset of single-thread program order, and</li>
1505 <li>When a <i>synchronizes-with</i> <tt>b</tt>, includes an edge from
1506 <tt>a</tt> to <tt>b</tt>. <i>Synchronizes-with</i> pairs are introduced
1507 by platform-specific techniques, like pthread locks, thread
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1508 creation, thread joining, etc., and by atomic instructions.
1509 (See also <a href="#ordering">Atomic Memory Ordering Constraints</a>).
1510 </li>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1511</ul>
1512
1513<p>Note that program order does not introduce <i>happens-before</i> edges
1514between a thread and signals executing inside that thread.</p>
1515
1516<p>Every (defined) read operation (load instructions, memcpy, atomic
1517loads/read-modify-writes, etc.) <var>R</var> reads a series of bytes written by
1518(defined) write operations (store instructions, atomic
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1519stores/read-modify-writes, memcpy, etc.). For the purposes of this section,
1520initialized globals are considered to have a write of the initializer which is
1521atomic and happens before any other read or write of the memory in question.
1522For each byte of a read <var>R</var>, <var>R<sub>byte</sub></var> may see
1523any write to the same byte, except:</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1524
1525<ul>
1526 <li>If <var>write<sub>1</sub></var> happens before
1527 <var>write<sub>2</sub></var>, and <var>write<sub>2</sub></var> happens
1528 before <var>R<sub>byte</sub></var>, then <var>R<sub>byte</sub></var>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1529 does not see <var>write<sub>1</sub></var>.
Bill Wendling0246bb72011-07-31 06:45:03 +0000[diff] [blame]1530 <li>If <var>R<sub>byte</sub></var> happens before
1531 <var>write<sub>3</sub></var>, then <var>R<sub>byte</sub></var> does not
1532 see <var>write<sub>3</sub></var>.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1533</ul>
1534
1535<p>Given that definition, <var>R<sub>byte</sub></var> is defined as follows:
1536<ul>
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1537 <li>If <var>R</var> is volatile, the result is target-dependent. (Volatile
1538 is supposed to give guarantees which can support
1539 <code>sig_atomic_t</code> in C/C++, and may be used for accesses to
1540 addresses which do not behave like normal memory. It does not generally
1541 provide cross-thread synchronization.)
1542 <li>Otherwise, if there is no write to the same byte that happens before
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1543 <var>R<sub>byte</sub></var>, <var>R<sub>byte</sub></var> returns
1544 <tt>undef</tt> for that byte.
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1545 <li>Otherwise, if <var>R<sub>byte</sub></var> may see exactly one write,
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1546 <var>R<sub>byte</sub></var> returns the value written by that
1547 write.</li>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1548 <li>Otherwise, if <var>R</var> is atomic, and all the writes
1549 <var>R<sub>byte</sub></var> may see are atomic, it chooses one of the
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1550 values written. See the <a href="#ordering">Atomic Memory Ordering
1551 Constraints</a> section for additional constraints on how the choice
1552 is made.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1553 <li>Otherwise <var>R<sub>byte</sub></var> returns <tt>undef</tt>.</li>
1554</ul>
1555
1556<p><var>R</var> returns the value composed of the series of bytes it read.
1557This implies that some bytes within the value may be <tt>undef</tt>
1558<b>without</b> the entire value being <tt>undef</tt>. Note that this only
1559defines the semantics of the operation; it doesn't mean that targets will
1560emit more than one instruction to read the series of bytes.</p>
1561
1562<p>Note that in cases where none of the atomic intrinsics are used, this model
1563places only one restriction on IR transformations on top of what is required
1564for single-threaded execution: introducing a store to a byte which might not
Eli Friedman101c81d2011-08-02 01:15:34 +0000[diff] [blame]1565otherwise be stored is not allowed in general. (Specifically, in the case
1566where another thread might write to and read from an address, introducing a
1567store can change a load that may see exactly one write into a load that may
1568see multiple writes.)</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1569
1570<!-- FIXME: This model assumes all targets where concurrency is relevant have
1571a byte-size store which doesn't affect adjacent bytes. As far as I can tell,
1572none of the backends currently in the tree fall into this category; however,
1573there might be targets which care. If there are, we want a paragraph
1574like the following:
1575
1576Targets may specify that stores narrower than a certain width are not
1577available; on such a target, for the purposes of this model, treat any
1578non-atomic write with an alignment or width less than the minimum width
1579as if it writes to the relevant surrounding bytes.
1580-->
1581
1582</div>
1583
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1584<!-- ======================================================================= -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]1585<h3>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1586 <a name="ordering">Atomic Memory Ordering Constraints</a>
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]1587</h3>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1588
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]1589<div>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1590
1591<p>Atomic instructions (<a href="#i_cmpxchg"><code>cmpxchg</code></a>,
Eli Friedman21006d42011-08-09 23:02:53 +0000[diff] [blame]1592<a href="#i_atomicrmw"><code>atomicrmw</code></a>,
1593<a href="#i_fence"><code>fence</code></a>,
1594<a href="#i_load"><code>atomic load</code></a>, and
Eli Friedman8fa281a2011-08-09 23:26:12 +0000[diff] [blame]1595<a href="#i_store"><code>atomic store</code></a>) take an ordering parameter
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1596that determines which other atomic instructions on the same address they
1597<i>synchronize with</i>. These semantics are borrowed from Java and C++0x,
1598but are somewhat more colloquial. If these descriptions aren't precise enough,
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1599check those specs (see spec references in the
1600<a href="Atomic.html#introduction">atomics guide</a>).
1601<a href="#i_fence"><code>fence</code></a> instructions
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1602treat these orderings somewhat differently since they don't take an address.
1603See that instruction's documentation for details.</p>
1604
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1605<p>For a simpler introduction to the ordering constraints, see the
1606<a href="Atomics.html">LLVM Atomic Instructions and Concurrency Guide</a>.</p>
1607
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1608<dl>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1609<dt><code>unordered</code></dt>
1610<dd>The set of values that can be read is governed by the happens-before
1611partial order. A value cannot be read unless some operation wrote it.
1612This is intended to provide a guarantee strong enough to model Java's
1613non-volatile shared variables. This ordering cannot be specified for
1614read-modify-write operations; it is not strong enough to make them atomic
1615in any interesting way.</dd>
1616<dt><code>monotonic</code></dt>
1617<dd>In addition to the guarantees of <code>unordered</code>, there is a single
1618total order for modifications by <code>monotonic</code> operations on each
1619address. All modification orders must be compatible with the happens-before
1620order. There is no guarantee that the modification orders can be combined to
1621a global total order for the whole program (and this often will not be
1622possible). The read in an atomic read-modify-write operation
1623(<a href="#i_cmpxchg"><code>cmpxchg</code></a> and
1624<a href="#i_atomicrmw"><code>atomicrmw</code></a>)
1625reads the value in the modification order immediately before the value it
1626writes. If one atomic read happens before another atomic read of the same
1627address, the later read must see the same value or a later value in the
1628address's modification order. This disallows reordering of
1629<code>monotonic</code> (or stronger) operations on the same address. If an
1630address is written <code>monotonic</code>ally by one thread, and other threads
1631<code>monotonic</code>ally read that address repeatedly, the other threads must
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1632eventually see the write. This corresponds to the C++0x/C1x
1633<code>memory_order_relaxed</code>.</dd>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1634<dt><code>acquire</code></dt>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1635<dd>In addition to the guarantees of <code>monotonic</code>,
Eli Friedmanc264b2f2011-08-24 20:28:39 +0000[diff] [blame]1636a <i>synchronizes-with</i> edge may be formed with a <code>release</code>
1637operation. This is intended to model C++'s <code>memory_order_acquire</code>.</dd>
1638<dt><code>release</code></dt>
1639<dd>In addition to the guarantees of <code>monotonic</code>, if this operation
1640writes a value which is subsequently read by an <code>acquire</code> operation,
1641it <i>synchronizes-with</i> that operation. (This isn't a complete
1642description; see the C++0x definition of a release sequence.) This corresponds
1643to the C++0x/C1x <code>memory_order_release</code>.</dd>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1644<dt><code>acq_rel</code> (acquire+release)</dt><dd>Acts as both an
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1645<code>acquire</code> and <code>release</code> operation on its address.
1646This corresponds to the C++0x/C1x <code>memory_order_acq_rel</code>.</dd>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1647<dt><code>seq_cst</code> (sequentially consistent)</dt><dd>
1648<dd>In addition to the guarantees of <code>acq_rel</code>
1649(<code>acquire</code> for an operation which only reads, <code>release</code>
1650for an operation which only writes), there is a global total order on all
1651sequentially-consistent operations on all addresses, which is consistent with
1652the <i>happens-before</i> partial order and with the modification orders of
1653all the affected addresses. Each sequentially-consistent read sees the last
Eli Friedman234bccd2011-08-22 21:35:27 +0000[diff] [blame]1654preceding write to the same address in this global order. This corresponds
1655to the C++0x/C1x <code>memory_order_seq_cst</code> and Java volatile.</dd>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1656</dl>
1657
1658<p id="singlethread">If an atomic operation is marked <code>singlethread</code>,
1659it only <i>synchronizes with</i> or participates in modification and seq_cst
1660total orderings with other operations running in the same thread (for example,
1661in signal handlers).</p>
1662
1663</div>
1664
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1665</div>
1666
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1667<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1668<h2><a name="typesystem">Type System</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1669<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1670
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1671<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1672
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1673<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1674 intermediate representation. Being typed enables a number of optimizations
1675 to be performed on the intermediate representation directly, without having
1676 to do extra analyses on the side before the transformation. A strong type
1677 system makes it easier to read the generated code and enables novel analyses
1678 and transformations that are not feasible to perform on normal three address
1679 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1680
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1681<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1682<h3>
1683 <a name="t_classifications">Type Classifications</a>
1684</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1685
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1686<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1687
1688<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1689
1690<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1691 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1692 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1693 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1694 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1695 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1696 </tr>
1697 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1698 <td><a href="#t_floating">floating point</a></td>
1699 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1700 </tr>
1701 <tr>
1702 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1703 <td><a href="#t_integer">integer</a>,
1704 <a href="#t_floating">floating point</a>,
1705 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1706 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1707 <a href="#t_struct">structure</a>,
1708 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1709 <a href="#t_label">label</a>,
1710 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1711 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1712 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1713 <tr>
1714 <td><a href="#t_primitive">primitive</a></td>
1715 <td><a href="#t_label">label</a>,
1716 <a href="#t_void">void</a>,
Tobias Grosser05387292010-12-28 20:29:31 +0000[diff] [blame]1717 <a href="#t_integer">integer</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1718 <a href="#t_floating">floating point</a>,
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1719 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1720 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1721 </tr>
1722 <tr>
1723 <td><a href="#t_derived">derived</a></td>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1724 <td><a href="#t_array">array</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1725 <a href="#t_function">function</a>,
1726 <a href="#t_pointer">pointer</a>,
1727 <a href="#t_struct">structure</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1728 <a href="#t_vector">vector</a>,
1729 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1730 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1731 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1732 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1733</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1734
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1735<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1736 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1737 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1738
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1739</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1740
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1741<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1742<h3>
1743 <a name="t_primitive">Primitive Types</a>
1744</h3>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1745
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1746<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1747
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1748<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1749 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1750
1751<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1752<h4>
1753 <a name="t_integer">Integer Type</a>
1754</h4>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1755
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1756<div>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1757
1758<h5>Overview:</h5>
1759<p>The integer type is a very simple type that simply specifies an arbitrary
1760 bit width for the integer type desired. Any bit width from 1 bit to
1761 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1762
1763<h5>Syntax:</h5>
1764<pre>
1765 iN
1766</pre>
1767
1768<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1769 value.</p>
1770
1771<h5>Examples:</h5>
1772<table class="layout">
1773 <tr class="layout">
1774 <td class="left"><tt>i1</tt></td>
1775 <td class="left">a single-bit integer.</td>
1776 </tr>
1777 <tr class="layout">
1778 <td class="left"><tt>i32</tt></td>
1779 <td class="left">a 32-bit integer.</td>
1780 </tr>
1781 <tr class="layout">
1782 <td class="left"><tt>i1942652</tt></td>
1783 <td class="left">a really big integer of over 1 million bits.</td>
1784 </tr>
1785</table>
1786
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1787</div>
1788
1789<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1790<h4>
1791 <a name="t_floating">Floating Point Types</a>
1792</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1793
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1794<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1795
1796<table>
1797 <tbody>
1798 <tr><th>Type</th><th>Description</th></tr>
1799 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1800 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1801 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1802 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1803 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1804 </tbody>
1805</table>
1806
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1807</div>
1808
1809<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1810<h4>
1811 <a name="t_x86mmx">X86mmx Type</a>
1812</h4>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1813
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1814<div>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1815
1816<h5>Overview:</h5>
1817<p>The x86mmx type represents a value held in an MMX register on an x86 machine. The operations allowed on it are quite limited: parameters and return values, load and store, and bitcast. User-specified MMX instructions are represented as intrinsic or asm calls with arguments and/or results of this type. There are no arrays, vectors or constants of this type.</p>
1818
1819<h5>Syntax:</h5>
1820<pre>
Dale Johannesen473a8c82010-10-01 01:07:02 +0000[diff] [blame]1821 x86mmx
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1822</pre>
1823
1824</div>
1825
1826<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1827<h4>
1828 <a name="t_void">Void Type</a>
1829</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1830
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1831<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1832
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1833<h5>Overview:</h5>
1834<p>The void type does not represent any value and has no size.</p>
1835
1836<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1837<pre>
1838 void
1839</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1840
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1841</div>
1842
1843<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1844<h4>
1845 <a name="t_label">Label Type</a>
1846</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1847
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1848<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1849
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1850<h5>Overview:</h5>
1851<p>The label type represents code labels.</p>
1852
1853<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1854<pre>
1855 label
1856</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1857
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1858</div>
1859
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1860<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1861<h4>
1862 <a name="t_metadata">Metadata Type</a>
1863</h4>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1864
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1865<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1866
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1867<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1868<p>The metadata type represents embedded metadata. No derived types may be
1869 created from metadata except for <a href="#t_function">function</a>
1870 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1871
1872<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1873<pre>
1874 metadata
1875</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1876
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1877</div>
1878
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1879</div>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1880
1881<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1882<h3>
1883 <a name="t_derived">Derived Types</a>
1884</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1885
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1886<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1887
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1888<p>The real power in LLVM comes from the derived types in the system. This is
1889 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1890 useful types. Each of these types contain one or more element types which
1891 may be a primitive type, or another derived type. For example, it is
1892 possible to have a two dimensional array, using an array as the element type
1893 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1894
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1895</div>
1896
1897
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1898<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1899<h4>
1900 <a name="t_aggregate">Aggregate Types</a>
1901</h4>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1902
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1903<div>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1904
1905<p>Aggregate Types are a subset of derived types that can contain multiple
1906 member types. <a href="#t_array">Arrays</a>,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]1907 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1908 aggregate types.</p>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1909
1910</div>
1911
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1912<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1913<h4>
1914 <a name="t_array">Array Type</a>
1915</h4>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1916
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1917<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1918
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1919<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1920<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1921 sequentially in memory. The array type requires a size (number of elements)
1922 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1923
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1924<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1925<pre>
1926 [&lt;# elements&gt; x &lt;elementtype&gt;]
1927</pre>
1928
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1929<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1930 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1931
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1932<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1933<table class="layout">
1934 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1935 <td class="left"><tt>[40 x i32]</tt></td>
1936 <td class="left">Array of 40 32-bit integer values.</td>
1937 </tr>
1938 <tr class="layout">
1939 <td class="left"><tt>[41 x i32]</tt></td>
1940 <td class="left">Array of 41 32-bit integer values.</td>
1941 </tr>
1942 <tr class="layout">
1943 <td class="left"><tt>[4 x i8]</tt></td>
1944 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1945 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1946</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1947<p>Here are some examples of multidimensional arrays:</p>
1948<table class="layout">
1949 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1950 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1951 <td class="left">3x4 array of 32-bit integer values.</td>
1952 </tr>
1953 <tr class="layout">
1954 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1955 <td class="left">12x10 array of single precision floating point values.</td>
1956 </tr>
1957 <tr class="layout">
1958 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1959 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1960 </tr>
1961</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1962
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1963<p>There is no restriction on indexing beyond the end of the array implied by
1964 a static type (though there are restrictions on indexing beyond the bounds
1965 of an allocated object in some cases). This means that single-dimension
1966 'variable sized array' addressing can be implemented in LLVM with a zero
1967 length array type. An implementation of 'pascal style arrays' in LLVM could
1968 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1969
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1970</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1971
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1972<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1973<h4>
1974 <a name="t_function">Function Type</a>
1975</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1976
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1977<div>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1978
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1979<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1980<p>The function type can be thought of as a function signature. It consists of
1981 a return type and a list of formal parameter types. The return type of a
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]1982 function type is a first class type or a void type.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1983
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1984<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1985<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1986 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1987</pre>
1988
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1989<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1990 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1991 which indicates that the function takes a variable number of arguments.
1992 Variable argument functions can access their arguments with
1993 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1994 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1995 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1996
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1997<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1998<table class="layout">
1999 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]2000 <td class="left"><tt>i32 (i32)</tt></td>
2001 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2002 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]2003 </tr><tr class="layout">
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]2004 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]2005 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2006 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]2007 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
2008 returning <tt>float</tt>.
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]2009 </td>
2010 </tr><tr class="layout">
2011 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2012 <td class="left">A vararg function that takes at least one
2013 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
2014 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]2015 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2016 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]2017 </tr><tr class="layout">
2018 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]2019 <td class="left">A function taking an <tt>i32</tt>, returning a
2020 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]2021 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2022 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2023</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2024
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2025</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2026
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2027<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2028<h4>
2029 <a name="t_struct">Structure Type</a>
2030</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2031
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2032<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2033
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2034<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2035<p>The structure type is used to represent a collection of data members together
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2036 in memory. The elements of a structure may be any type that has a size.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2037
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]2038<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
2039 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
2040 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
2041 Structures in registers are accessed using the
2042 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
2043 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2044
2045<p>Structures may optionally be "packed" structures, which indicate that the
2046 alignment of the struct is one byte, and that there is no padding between
Chris Lattner2c38d652011-08-12 17:31:02 +0000[diff] [blame]2047 the elements. In non-packed structs, padding between field types is inserted
2048 as defined by the TargetData string in the module, which is required to match
2049 what the underlying processor expects.</p>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2050
Chris Lattner2c38d652011-08-12 17:31:02 +0000[diff] [blame]2051<p>Structures can either be "literal" or "identified". A literal structure is
2052 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) whereas identified
2053 types are always defined at the top level with a name. Literal types are
2054 uniqued by their contents and can never be recursive or opaque since there is
Chris Lattneraa175c32011-08-12 18:12:40 +0000[diff] [blame]2055 no way to write one. Identified types can be recursive, can be opaqued, and are
Chris Lattner2c38d652011-08-12 17:31:02 +0000[diff] [blame]2056 never uniqued.
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2057</p>
2058
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2059<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2060<pre>
Chris Lattner2c38d652011-08-12 17:31:02 +0000[diff] [blame]2061 %T1 = type { &lt;type list&gt; } <i>; Identified normal struct type</i>
2062 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Identified packed struct type</i>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2063</pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2064
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2065<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2066<table class="layout">
2067 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2068 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
2069 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2070 </tr>
2071 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2072 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
2073 <td class="left">A pair, where the first element is a <tt>float</tt> and the
2074 second element is a <a href="#t_pointer">pointer</a> to a
2075 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
2076 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2077 </tr>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2078 <tr class="layout">
2079 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
2080 <td class="left">A packed struct known to be 5 bytes in size.</td>
2081 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2082</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2083
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2084</div>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2085
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2086<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2087<h4>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]2088 <a name="t_opaque">Opaque Structure Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2089</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2090
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2091<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2092
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2093<h5>Overview:</h5>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]2094<p>Opaque structure types are used to represent named structure types that do
2095 not have a body specified. This corresponds (for example) to the C notion of
2096 a forward declared structure.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2097
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2098<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2099<pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2100 %X = type opaque
2101 %52 = type opaque
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2102</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2103
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2104<h5>Examples:</h5>
2105<table class="layout">
2106 <tr class="layout">
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2107 <td class="left"><tt>opaque</tt></td>
2108 <td class="left">An opaque type.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2109 </tr>
2110</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2111
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2112</div>
2113
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2114
2115
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2116<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2117<h4>
2118 <a name="t_pointer">Pointer Type</a>
2119</h4>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2120
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2121<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2122
2123<h5>Overview:</h5>
Dan Gohmanff3ef322010-02-25 16:50:07 +0000[diff] [blame]2124<p>The pointer type is used to specify memory locations.
2125 Pointers are commonly used to reference objects in memory.</p>
2126
2127<p>Pointer types may have an optional address space attribute defining the
2128 numbered address space where the pointed-to object resides. The default
2129 address space is number zero. The semantics of non-zero address
2130 spaces are target-specific.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2131
2132<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
2133 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2134
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2135<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2136<pre>
2137 &lt;type&gt; *
2138</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2139
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2140<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2141<table class="layout">
2142 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2143 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2144 <td class="left">A <a href="#t_pointer">pointer</a> to <a
2145 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
2146 </tr>
2147 <tr class="layout">
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]2148 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2149 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2150 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2151 <tt>i32</tt>.</td>
2152 </tr>
2153 <tr class="layout">
2154 <td class="left"><tt>i32 addrspace(5)*</tt></td>
2155 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
2156 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2157 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2158</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2159
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2160</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2161
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2162<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2163<h4>
2164 <a name="t_vector">Vector Type</a>
2165</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2166
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2167<div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2168
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2169<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2170<p>A vector type is a simple derived type that represents a vector of elements.
2171 Vector types are used when multiple primitive data are operated in parallel
2172 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]2173 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2174 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2175
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2176<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2177<pre>
2178 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2179</pre>
2180
Chris Lattner7d2e7be2010-10-10 18:20:35 +0000[diff] [blame]2181<p>The number of elements is a constant integer value larger than 0; elementtype
2182 may be any integer or floating point type. Vectors of size zero are not
2183 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2184
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2185<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2186<table class="layout">
2187 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2188 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
2189 <td class="left">Vector of 4 32-bit integer values.</td>
2190 </tr>
2191 <tr class="layout">
2192 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
2193 <td class="left">Vector of 8 32-bit floating-point values.</td>
2194 </tr>
2195 <tr class="layout">
2196 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2197 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2198 </tr>
2199</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2200
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2201</div>
2202
Bill Wendlingaf75f0c2011-07-31 06:47:33 +0000[diff] [blame]2203</div>
2204
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2205<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2206<h2><a name="constants">Constants</a></h2>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2207<!-- *********************************************************************** -->
2208
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2209<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2210
2211<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2212 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2213
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2214<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2215<h3>
2216 <a name="simpleconstants">Simple Constants</a>
2217</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2218
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2219<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2220
2221<dl>
2222 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2223 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]2224 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2225
2226 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2227 <dd>Standard integers (such as '4') are constants of
2228 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2229 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2230
2231 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2232 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2233 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2234 notation (see below). The assembler requires the exact decimal value of a
2235 floating-point constant. For example, the assembler accepts 1.25 but
2236 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2237 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2238
2239 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2240 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2241 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2242</dl>
2243
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2244<p>The one non-intuitive notation for constants is the hexadecimal form of
2245 floating point constants. For example, the form '<tt>double
2246 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2247 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2248 constants are required (and the only time that they are generated by the
2249 disassembler) is when a floating point constant must be emitted but it cannot
2250 be represented as a decimal floating point number in a reasonable number of
2251 digits. For example, NaN's, infinities, and other special values are
2252 represented in their IEEE hexadecimal format so that assembly and disassembly
2253 do not cause any bits to change in the constants.</p>
2254
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]2255<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2256 represented using the 16-digit form shown above (which matches the IEEE754
2257 representation for double); float values must, however, be exactly
2258 representable as IEE754 single precision. Hexadecimal format is always used
2259 for long double, and there are three forms of long double. The 80-bit format
2260 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2261 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2262 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2263 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2264 currently supported target uses this format. Long doubles will only work if
2265 they match the long double format on your target. All hexadecimal formats
2266 are big-endian (sign bit at the left).</p>
2267
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]2268<p>There are no constants of type x86mmx.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2269</div>
2270
2271<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2272<h3>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2273<a name="aggregateconstants"></a> <!-- old anchor -->
2274<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2275</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2276
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2277<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2278
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2279<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2280 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2281
2282<dl>
2283 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2284 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2285 type definitions (a comma separated list of elements, surrounded by braces
2286 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2287 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2288 Structure constants must have <a href="#t_struct">structure type</a>, and
2289 the number and types of elements must match those specified by the
2290 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2291
2292 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2293 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2294 definitions (a comma separated list of elements, surrounded by square
2295 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2296 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2297 the number and types of elements must match those specified by the
2298 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2299
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2300 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2301 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2302 definitions (a comma separated list of elements, surrounded by
2303 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2304 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2305 have <a href="#t_vector">vector type</a>, and the number and types of
2306 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2307
2308 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2309 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2310 value to zero of <em>any</em> type, including scalar and
2311 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2312 This is often used to avoid having to print large zero initializers
2313 (e.g. for large arrays) and is always exactly equivalent to using explicit
2314 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2315
2316 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2317 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2318 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2319 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2320 be interpreted as part of the instruction stream, metadata is a place to
2321 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2322</dl>
2323
2324</div>
2325
2326<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2327<h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2328 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2329</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2330
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2331<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2332
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2333<p>The addresses of <a href="#globalvars">global variables</a>
2334 and <a href="#functionstructure">functions</a> are always implicitly valid
2335 (link-time) constants. These constants are explicitly referenced when
2336 the <a href="#identifiers">identifier for the global</a> is used and always
2337 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2338 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2339
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2340<pre class="doc_code">
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2341@X = global i32 17
2342@Y = global i32 42
2343@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2344</pre>
2345
2346</div>
2347
2348<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2349<h3>
2350 <a name="undefvalues">Undefined Values</a>
2351</h3>
2352
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2353<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2354
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2355<p>The string '<tt>undef</tt>' can be used anywhere a constant is expected, and
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]2356 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2357 Undefined values may be of any type (other than '<tt>label</tt>'
2358 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2359
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2360<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2361 program is well defined no matter what value is used. This gives the
2362 compiler more freedom to optimize. Here are some examples of (potentially
2363 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2364
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2365
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2366<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2367 %A = add %X, undef
2368 %B = sub %X, undef
2369 %C = xor %X, undef
2370Safe:
2371 %A = undef
2372 %B = undef
2373 %C = undef
2374</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2375
2376<p>This is safe because all of the output bits are affected by the undef bits.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2377 Any output bit can have a zero or one depending on the input bits.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2378
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2379<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2380 %A = or %X, undef
2381 %B = and %X, undef
2382Safe:
2383 %A = -1
2384 %B = 0
2385Unsafe:
2386 %A = undef
2387 %B = undef
2388</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2389
2390<p>These logical operations have bits that are not always affected by the input.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2391 For example, if <tt>%X</tt> has a zero bit, then the output of the
2392 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2393 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2394 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2395 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2396 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2397 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2398 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2399
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2400<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2401 %A = select undef, %X, %Y
2402 %B = select undef, 42, %Y
2403 %C = select %X, %Y, undef
2404Safe:
2405 %A = %X (or %Y)
2406 %B = 42 (or %Y)
2407 %C = %Y
2408Unsafe:
2409 %A = undef
2410 %B = undef
2411 %C = undef
2412</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2413
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2414<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2415 branch) conditions can go <em>either way</em>, but they have to come from one
2416 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2417 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2418 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2419 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2420 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2421 eliminated.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2422
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2423<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2424 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2425
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2426 %B = undef
2427 %C = xor %B, %B
2428
2429 %D = undef
2430 %E = icmp lt %D, 4
2431 %F = icmp gte %D, 4
2432
2433Safe:
2434 %A = undef
2435 %B = undef
2436 %C = undef
2437 %D = undef
2438 %E = undef
2439 %F = undef
2440</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2441
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2442<p>This example points out that two '<tt>undef</tt>' operands are not
2443 necessarily the same. This can be surprising to people (and also matches C
2444 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2445 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2446 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2447 its value over its "live range". This is true because the variable doesn't
2448 actually <em>have a live range</em>. Instead, the value is logically read
2449 from arbitrary registers that happen to be around when needed, so the value
2450 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2451 need to have the same semantics or the core LLVM "replace all uses with"
2452 concept would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2453
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2454<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2455 %A = fdiv undef, %X
2456 %B = fdiv %X, undef
2457Safe:
2458 %A = undef
2459b: unreachable
2460</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2461
2462<p>These examples show the crucial difference between an <em>undefined
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2463 value</em> and <em>undefined behavior</em>. An undefined value (like
2464 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2465 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2466 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2467 defined on SNaN's. However, in the second example, we can make a more
2468 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2469 arbitrary value, we are allowed to assume that it could be zero. Since a
2470 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2471 the operation does not execute at all. This allows us to delete the divide and
2472 all code after it. Because the undefined operation "can't happen", the
2473 optimizer can assume that it occurs in dead code.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2474
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2475<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2476a: store undef -> %X
2477b: store %X -> undef
2478Safe:
2479a: &lt;deleted&gt;
2480b: unreachable
2481</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2482
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2483<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2484 undefined value can be assumed to not have any effect; we can assume that the
2485 value is overwritten with bits that happen to match what was already there.
2486 However, a store <em>to</em> an undefined location could clobber arbitrary
2487 memory, therefore, it has undefined behavior.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2488
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2489</div>
2490
2491<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2492<h3>
2493 <a name="trapvalues">Trap Values</a>
2494</h3>
2495
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2496<div>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2497
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2498<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2499 instead of representing an unspecified bit pattern, they represent the
2500 fact that an instruction or constant expression which cannot evoke side
2501 effects has nevertheless detected a condition which results in undefined
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2502 behavior.</p>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2503
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2504<p>There is currently no way of representing a trap value in the IR; they
Dan Gohman855abed2010-05-03 14:51:43 +0000[diff] [blame]2505 only exist when produced by operations such as
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2506 <a href="#i_add"><tt>add</tt></a> with the <tt>nsw</tt> flag.</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2507
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2508<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2509
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2510<ul>
2511<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2512 their operands.</li>
2513
2514<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2515 to their dynamic predecessor basic block.</li>
2516
2517<li>Function arguments depend on the corresponding actual argument values in
2518 the dynamic callers of their functions.</li>
2519
2520<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2521 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2522 control back to them.</li>
2523
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2524<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2525 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2526 or exception-throwing call instructions that dynamically transfer control
2527 back to them.</li>
2528
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2529<li>Non-volatile loads and stores depend on the most recent stores to all of the
2530 referenced memory addresses, following the order in the IR
2531 (including loads and stores implied by intrinsics such as
2532 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2533
Dan Gohman7c24ff12010-05-03 14:59:34 +0000[diff] [blame]2534<!-- TODO: In the case of multiple threads, this only applies if the store
2535 "happens-before" the load or store. -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2536
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2537<!-- TODO: floating-point exception state -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2538
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2539<li>An instruction with externally visible side effects depends on the most
2540 recent preceding instruction with externally visible side effects, following
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]2541 the order in the IR. (This includes
2542 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2543
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2544<li>An instruction <i>control-depends</i> on a
2545 <a href="#terminators">terminator instruction</a>
2546 if the terminator instruction has multiple successors and the instruction
2547 is always executed when control transfers to one of the successors, and
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2548 may not be executed when control is transferred to another.</li>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2549
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2550<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2551 instruction if the set of instructions it otherwise depends on would be
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2552 different if the terminator had transferred control to a different
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2553 successor.</li>
2554
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2555<li>Dependence is transitive.</li>
2556
2557</ul>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2558
2559<p>Whenever a trap value is generated, all values which depend on it evaluate
2560 to trap. If they have side effects, the evoke their side effects as if each
2561 operand with a trap value were undef. If they have externally-visible side
2562 effects, the behavior is undefined.</p>
2563
2564<p>Here are some examples:</p>
Dan Gohmanc30f6e12010-04-26 20:54:53 +0000[diff] [blame]2565
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2566<pre class="doc_code">
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2567entry:
2568 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2569 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2570 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2571 store i32 0, i32* %trap_yet_again ; undefined behavior
2572
2573 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2574 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2575
2576 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2577
2578 %narrowaddr = bitcast i32* @g to i16*
2579 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2580 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2581 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2582
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2583 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2584 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2585
2586true:
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2587 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2588 ; it has undefined behavior.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2589 br label %end
2590
2591end:
2592 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2593 ; Both edges into this PHI are
2594 ; control-dependent on %cmp, so this
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2595 ; always results in a trap value.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2596
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2597 volatile store i32 0, i32* @g ; This would depend on the store in %true
2598 ; if %cmp is true, or the store in %entry
2599 ; otherwise, so this is undefined behavior.
2600
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2601 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2602 ; The same branch again, but this time the
2603 ; true block doesn't have side effects.
2604
2605second_true:
2606 ; No side effects!
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2607 ret void
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2608
2609second_end:
2610 volatile store i32 0, i32* @g ; This time, the instruction always depends
2611 ; on the store in %end. Also, it is
2612 ; control-equivalent to %end, so this is
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2613 ; well-defined (again, ignoring earlier
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2614 ; undefined behavior in this example).
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2615</pre>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2616
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2617</div>
2618
2619<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2620<h3>
2621 <a name="blockaddress">Addresses of Basic Blocks</a>
2622</h3>
2623
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2624<div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2625
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2626<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2627
2628<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2629 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2630 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2631
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2632<p>This value only has defined behavior when used as an operand to the
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2633 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2634 comparisons against null. Pointer equality tests between labels addresses
2635 results in undefined behavior &mdash; though, again, comparison against null
2636 is ok, and no label is equal to the null pointer. This may be passed around
2637 as an opaque pointer sized value as long as the bits are not inspected. This
2638 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2639 long as the original value is reconstituted before the <tt>indirectbr</tt>
2640 instruction.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2641
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2642<p>Finally, some targets may provide defined semantics when using the value as
2643 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2644
2645</div>
2646
2647
2648<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2649<h3>
2650 <a name="constantexprs">Constant Expressions</a>
2651</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2652
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2653<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2654
2655<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2656 to be used as constants. Constant expressions may be of
2657 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2658 operation that does not have side effects (e.g. load and call are not
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2659 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2660
2661<dl>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2662 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2663 <dd>Truncate a constant to another type. The bit size of CST must be larger
2664 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2665
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2666 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2667 <dd>Zero extend a constant to another type. The bit size of CST must be
Duncan Sands28afd432010-07-13 12:06:14 +0000[diff] [blame]2668 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2669
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2670 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2671 <dd>Sign extend a constant to another type. The bit size of CST must be
Duncan Sands28afd432010-07-13 12:06:14 +0000[diff] [blame]2672 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2673
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2674 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2675 <dd>Truncate a floating point constant to another floating point type. The
2676 size of CST must be larger than the size of TYPE. Both types must be
2677 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2678
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2679 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2680 <dd>Floating point extend a constant to another type. The size of CST must be
2681 smaller or equal to the size of TYPE. Both types must be floating
2682 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2683
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2684 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2685 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2686 constant. TYPE must be a scalar or vector integer type. CST must be of
2687 scalar or vector floating point type. Both CST and TYPE must be scalars,
2688 or vectors of the same number of elements. If the value won't fit in the
2689 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2690
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2691 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2692 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2693 constant. TYPE must be a scalar or vector integer type. CST must be of
2694 scalar or vector floating point type. Both CST and TYPE must be scalars,
2695 or vectors of the same number of elements. If the value won't fit in the
2696 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2697
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2698 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2699 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2700 constant. TYPE must be a scalar or vector floating point type. CST must be
2701 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2702 vectors of the same number of elements. If the value won't fit in the
2703 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2704
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2705 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2706 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2707 constant. TYPE must be a scalar or vector floating point type. CST must be
2708 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2709 vectors of the same number of elements. If the value won't fit in the
2710 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2711
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2712 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2713 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2714 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2715 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2716 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2717
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2718 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2719 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2720 type. CST must be of integer type. The CST value is zero extended,
2721 truncated, or unchanged to make it fit in a pointer size. This one is
2722 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2723
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2724 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2725 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2726 are the same as those for the <a href="#i_bitcast">bitcast
2727 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2728
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2729 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2730 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2731 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2732 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2733 instruction, the index list may have zero or more indexes, which are
2734 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2735
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2736 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2737 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2738
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2739 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2740 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2741
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2742 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2743 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2744
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2745 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2746 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2747 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2748
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2749 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2750 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2751 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2752
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2753 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2754 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2755 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2756
Nick Lewycky9e130ce2010-05-29 06:44:15 +0000[diff] [blame]2757 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2758 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2759 constants. The index list is interpreted in a similar manner as indices in
2760 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2761 index value must be specified.</dd>
2762
2763 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2764 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2765 constants. The index list is interpreted in a similar manner as indices in
2766 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2767 index value must be specified.</dd>
2768
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2769 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2770 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2771 be any of the <a href="#binaryops">binary</a>
2772 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2773 on operands are the same as those for the corresponding instruction
2774 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2775</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2776
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2777</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2778
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2779</div>
2780
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2781<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2782<h2><a name="othervalues">Other Values</a></h2>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2783<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2784<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2785<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2786<h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2787<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2788</h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2789
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2790<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2791
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2792<p>LLVM supports inline assembler expressions (as opposed
2793 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2794 a special value. This value represents the inline assembler as a string
2795 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2796 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2797 expression has side effects, and a flag indicating whether the function
2798 containing the asm needs to align its stack conservatively. An example
2799 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2800
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2801<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2802i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2803</pre>
2804
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2805<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2806 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2807 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2808
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2809<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2810%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2811</pre>
2812
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2813<p>Inline asms with side effects not visible in the constraint list must be
2814 marked as having side effects. This is done through the use of the
2815 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2816
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2817<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2818call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2819</pre>
2820
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2821<p>In some cases inline asms will contain code that will not work unless the
2822 stack is aligned in some way, such as calls or SSE instructions on x86,
2823 yet will not contain code that does that alignment within the asm.
2824 The compiler should make conservative assumptions about what the asm might
2825 contain and should generate its usual stack alignment code in the prologue
2826 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2827
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2828<pre class="doc_code">
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2829call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2830</pre>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2831
2832<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2833 first.</p>
2834
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2835<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2836 documented here. Constraints on what can be done (e.g. duplication, moving,
2837 etc need to be documented). This is probably best done by reference to
2838 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2839
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2840<h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2841<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2842</h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2843
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2844<div>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2845
2846<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2847 attached to it that contains a list of constant integers. If present, the
2848 code generator will use the integer as the location cookie value when report
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2849 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]2850 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2851 source code that produced it. For example:</p>
2852
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2853<pre class="doc_code">
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2854call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2855...
2856!42 = !{ i32 1234567 }
2857</pre>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2858
2859<p>It is up to the front-end to make sense of the magic numbers it places in the
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2860 IR. If the MDNode contains multiple constants, the code generator will use
2861 the one that corresponds to the line of the asm that the error occurs on.</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2862
2863</div>
2864
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2865</div>
2866
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2867<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2868<h3>
2869 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2870</h3>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2871
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2872<div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2873
2874<p>LLVM IR allows metadata to be attached to instructions in the program that
2875 can convey extra information about the code to the optimizers and code
2876 generator. One example application of metadata is source-level debug
2877 information. There are two metadata primitives: strings and nodes. All
2878 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2879 preceding exclamation point ('<tt>!</tt>').</p>
2880
2881<p>A metadata string is a string surrounded by double quotes. It can contain
2882 any character by escaping non-printable characters with "\xx" where "xx" is
2883 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2884
2885<p>Metadata nodes are represented with notation similar to structure constants
2886 (a comma separated list of elements, surrounded by braces and preceded by an
2887 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2888 10}</tt>". Metadata nodes can have any values as their operand.</p>
2889
2890<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2891 metadata nodes, which can be looked up in the module symbol table. For
2892 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2893
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2894<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2895 function is using two metadata arguments.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2896
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2897<div class="doc_code">
2898<pre>
2899call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2900</pre>
2901</div>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2902
2903<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2904 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2905
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2906<div class="doc_code">
2907<pre>
2908%indvar.next = add i64 %indvar, 1, !dbg !21
2909</pre>
2910</div>
2911
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2912</div>
2913
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2914</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2915
2916<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2917<h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2918 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2919</h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2920<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2921<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2922<p>LLVM has a number of "magic" global variables that contain data that affect
2923code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2924of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2925section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2926by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2927
2928<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2929<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2930<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2931</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2932
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2933<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2934
2935<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2936href="#linkage_appending">appending linkage</a>. This array contains a list of
2937pointers to global variables and functions which may optionally have a pointer
2938cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2939
2940<pre>
2941 @X = global i8 4
2942 @Y = global i32 123
2943
2944 @llvm.used = appending global [2 x i8*] [
2945 i8* @X,
2946 i8* bitcast (i32* @Y to i8*)
2947 ], section "llvm.metadata"
2948</pre>
2949
2950<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2951compiler, assembler, and linker are required to treat the symbol as if there is
2952a reference to the global that it cannot see. For example, if a variable has
2953internal linkage and no references other than that from the <tt>@llvm.used</tt>
2954list, it cannot be deleted. This is commonly used to represent references from
2955inline asms and other things the compiler cannot "see", and corresponds to
2956"attribute((used))" in GNU C.</p>
2957
2958<p>On some targets, the code generator must emit a directive to the assembler or
2959object file to prevent the assembler and linker from molesting the symbol.</p>
2960
2961</div>
2962
2963<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2964<h3>
2965 <a name="intg_compiler_used">
2966 The '<tt>llvm.compiler.used</tt>' Global Variable
2967 </a>
2968</h3>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2969
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2970<div>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2971
2972<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2973<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2974touching the symbol. On targets that support it, this allows an intelligent
2975linker to optimize references to the symbol without being impeded as it would be
2976by <tt>@llvm.used</tt>.</p>
2977
2978<p>This is a rare construct that should only be used in rare circumstances, and
2979should not be exposed to source languages.</p>
2980
2981</div>
2982
2983<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2984<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2985<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2986</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2987
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2988<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2989<pre>
2990%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2991@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2992</pre>
2993<p>The <tt>@llvm.global_ctors</tt> array contains a list of constructor functions and associated priorities. The functions referenced by this array will be called in ascending order of priority (i.e. lowest first) when the module is loaded. The order of functions with the same priority is not defined.
2994</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2995
2996</div>
2997
2998<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2999<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3000<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3001</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3002
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3003<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]3004<pre>
3005%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]3006@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]3007</pre>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3008
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]3009<p>The <tt>@llvm.global_dtors</tt> array contains a list of destructor functions and associated priorities. The functions referenced by this array will be called in descending order of priority (i.e. highest first) when the module is loaded. The order of functions with the same priority is not defined.
3010</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3011
3012</div>
3013
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3014</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3015
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]3016<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3017<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3018<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3019
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3020<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3021
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3022<p>The LLVM instruction set consists of several different classifications of
3023 instructions: <a href="#terminators">terminator
3024 instructions</a>, <a href="#binaryops">binary instructions</a>,
3025 <a href="#bitwiseops">bitwise binary instructions</a>,
3026 <a href="#memoryops">memory instructions</a>, and
3027 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3028
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3029<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3030<h3>
3031 <a name="terminators">Terminator Instructions</a>
3032</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3033
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3034<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3035
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3036<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
3037 in a program ends with a "Terminator" instruction, which indicates which
3038 block should be executed after the current block is finished. These
3039 terminator instructions typically yield a '<tt>void</tt>' value: they produce
3040 control flow, not values (the one exception being the
3041 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
3042
Chris Lattner6445ecb2011-08-02 20:29:13 +0000[diff] [blame]3043<p>The terminator instructions are:
3044 '<a href="#i_ret"><tt>ret</tt></a>',
3045 '<a href="#i_br"><tt>br</tt></a>',
3046 '<a href="#i_switch"><tt>switch</tt></a>',
3047 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>',
3048 '<a href="#i_invoke"><tt>invoke</tt></a>',
3049 '<a href="#i_unwind"><tt>unwind</tt></a>',
3050 '<a href="#i_resume"><tt>resume</tt></a>', and
3051 '<a href="#i_unreachable"><tt>unreachable</tt></a>'.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3052
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3053<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3054<h4>
3055 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
3056</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3057
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3058<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3059
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3060<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]3061<pre>
3062 ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3063 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3064</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3065
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3066<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3067<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
3068 a value) from a function back to the caller.</p>
3069
3070<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
3071 value and then causes control flow, and one that just causes control flow to
3072 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3073
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3074<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3075<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
3076 return value. The type of the return value must be a
3077 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]3078
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3079<p>A function is not <a href="#wellformed">well formed</a> if it it has a
3080 non-void return type and contains a '<tt>ret</tt>' instruction with no return
3081 value or a return value with a type that does not match its type, or if it
3082 has a void return type and contains a '<tt>ret</tt>' instruction with a
3083 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3084
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3085<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3086<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
3087 the calling function's context. If the caller is a
3088 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
3089 instruction after the call. If the caller was an
3090 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
3091 the beginning of the "normal" destination block. If the instruction returns
3092 a value, that value shall set the call or invoke instruction's return
3093 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3094
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3095<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3096<pre>
3097 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3098 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]3099 ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3100</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3101
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3102</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3103<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3104<h4>
3105 <a name="i_br">'<tt>br</tt>' Instruction</a>
3106</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3107
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3108<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3109
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3110<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3111<pre>
Bill Wendlingb3aa4712011-07-26 10:41:15 +0000[diff] [blame]3112 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;
3113 br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3114</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3115
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3116<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3117<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3118 different basic block in the current function. There are two forms of this
3119 instruction, corresponding to a conditional branch and an unconditional
3120 branch.</p>
3121
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3122<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3123<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3124 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3125 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3126 target.</p>
3127
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3128<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3129<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3130 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3131 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3132 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3133
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3134<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]3135<pre>
3136Test:
3137 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3138 br i1 %cond, label %IfEqual, label %IfUnequal
3139IfEqual:
3140 <a href="#i_ret">ret</a> i32 1
3141IfUnequal:
3142 <a href="#i_ret">ret</a> i32 0
3143</pre>
3144
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3145</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3146
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3147<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3148<h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3149 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3150</h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3151
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3152<div>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3153
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3154<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3155<pre>
3156 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3157</pre>
3158
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3159<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3160<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3161 several different places. It is a generalization of the '<tt>br</tt>'
3162 instruction, allowing a branch to occur to one of many possible
3163 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3164
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3165<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3166<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3167 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3168 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3169 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3170
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3171<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3172<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3173 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3174 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]3175 transferred to the corresponding destination; otherwise, control flow is
3176 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3177
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3178<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3179<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3180 <tt>switch</tt> instruction, this instruction may be code generated in
3181 different ways. For example, it could be generated as a series of chained
3182 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3183
3184<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3185<pre>
3186 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3187 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3188 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3189
3190 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3191 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3192
3193 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3194 switch i32 %val, label %otherwise [ i32 0, label %onzero
3195 i32 1, label %onone
3196 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3197</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3198
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3199</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3200
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3201
3202<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3203<h4>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3204 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3205</h4>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3206
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3207<div>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3208
3209<h5>Syntax:</h5>
3210<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3211 indirectbr &lt;somety&gt;* &lt;address&gt;, [ label &lt;dest1&gt;, label &lt;dest2&gt;, ... ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3212</pre>
3213
3214<h5>Overview:</h5>
3215
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3216<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3217 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]3218 "<tt>address</tt>". Address must be derived from a <a
3219 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3220
3221<h5>Arguments:</h5>
3222
3223<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3224 rest of the arguments indicate the full set of possible destinations that the
3225 address may point to. Blocks are allowed to occur multiple times in the
3226 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3227
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3228<p>This destination list is required so that dataflow analysis has an accurate
3229 understanding of the CFG.</p>
3230
3231<h5>Semantics:</h5>
3232
3233<p>Control transfers to the block specified in the address argument. All
3234 possible destination blocks must be listed in the label list, otherwise this
3235 instruction has undefined behavior. This implies that jumps to labels
3236 defined in other functions have undefined behavior as well.</p>
3237
3238<h5>Implementation:</h5>
3239
3240<p>This is typically implemented with a jump through a register.</p>
3241
3242<h5>Example:</h5>
3243<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3244 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3245</pre>
3246
3247</div>
3248
3249
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3250<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3251<h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3252 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3253</h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3254
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3255<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3256
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3257<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3258<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3259 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner76b8a332006-05-14 18:23:06 +0000[diff] [blame]3260 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3261</pre>
3262
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3263<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3264<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3265 function, with the possibility of control flow transfer to either the
3266 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3267 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3268 control flow will return to the "normal" label. If the callee (or any
3269 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3270 instruction, control is interrupted and continued at the dynamically nearest
3271 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3272
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3273<p>The '<tt>exception</tt>' label is a
3274 <i><a href="ExceptionHandling.html#overview">landing pad</a></i> for the
3275 exception. As such, '<tt>exception</tt>' label is required to have the
3276 "<a href="#i_landingpad"><tt>landingpad</tt></a>" instruction, which contains
3277 the information about about the behavior of the program after unwinding
3278 happens, as its first non-PHI instruction. The restrictions on the
3279 "<tt>landingpad</tt>" instruction's tightly couples it to the
3280 "<tt>invoke</tt>" instruction, so that the important information contained
3281 within the "<tt>landingpad</tt>" instruction can't be lost through normal
3282 code motion.</p>
3283
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3284<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3285<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3286
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3287<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3288 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3289 convention</a> the call should use. If none is specified, the call
3290 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3291
3292 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3293 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3294 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3295
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3296 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3297 function value being invoked. In most cases, this is a direct function
3298 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3299 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3300
3301 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3302 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3303
3304 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]3305 signature argument types and parameter attributes. All arguments must be
3306 of <a href="#t_firstclass">first class</a> type. If the function
3307 signature indicates the function accepts a variable number of arguments,
3308 the extra arguments can be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3309
3310 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3311 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3312
3313 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3314 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3315
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3316 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3317 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3318 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3319</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3320
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3321<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3322<p>This instruction is designed to operate as a standard
3323 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3324 primary difference is that it establishes an association with a label, which
3325 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3326
3327<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3328 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3329 exception. Additionally, this is important for implementation of
3330 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3331
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3332<p>For the purposes of the SSA form, the definition of the value returned by the
3333 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3334 block to the "normal" label. If the callee unwinds then no return value is
3335 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]3336
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3337<p>Note that the code generator does not yet completely support unwind, and
3338that the invoke/unwind semantics are likely to change in future versions.</p>
3339
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3340<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3341<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3342 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3343 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3344 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3345 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3346</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3347
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3348</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3349
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3350<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3351
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3352<h4>
3353 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3354</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3355
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3356<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3357
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3358<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3359<pre>
3360 unwind
3361</pre>
3362
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3363<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3364<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3365 at the first callee in the dynamic call stack which used
3366 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3367 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3368
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3369<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3370<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3371 immediately halt. The dynamic call stack is then searched for the
3372 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3373 Once found, execution continues at the "exceptional" destination block
3374 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3375 instruction in the dynamic call chain, undefined behavior results.</p>
3376
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3377<p>Note that the code generator does not yet completely support unwind, and
3378that the invoke/unwind semantics are likely to change in future versions.</p>
3379
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3380</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3381
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3382 <!-- _______________________________________________________________________ -->
3383
3384<h4>
3385 <a name="i_resume">'<tt>resume</tt>' Instruction</a>
3386</h4>
3387
3388<div>
3389
3390<h5>Syntax:</h5>
3391<pre>
3392 resume &lt;type&gt; &lt;value&gt;
3393</pre>
3394
3395<h5>Overview:</h5>
3396<p>The '<tt>resume</tt>' instruction is a terminator instruction that has no
3397 successors.</p>
3398
3399<h5>Arguments:</h5>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3400<p>The '<tt>resume</tt>' instruction requires one argument, which must have the
Bill Wendlinge4ad50b2011-08-03 18:37:32 +0000[diff] [blame]3401 same type as the result of any '<tt>landingpad</tt>' instruction in the same
3402 function.</p>
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3403
3404<h5>Semantics:</h5>
3405<p>The '<tt>resume</tt>' instruction resumes propagation of an existing
3406 (in-flight) exception whose unwinding was interrupted with
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3407 a <a href="#i_landingpad"><tt>landingpad</tt></a> instruction.</p>
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3408
3409<h5>Example:</h5>
3410<pre>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3411 resume { i8*, i32 } %exn
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3412</pre>
3413
3414</div>
3415
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3416<!-- _______________________________________________________________________ -->
3417
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3418<h4>
3419 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3420</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3421
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3422<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3423
3424<h5>Syntax:</h5>
3425<pre>
3426 unreachable
3427</pre>
3428
3429<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3430<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3431 instruction is used to inform the optimizer that a particular portion of the
3432 code is not reachable. This can be used to indicate that the code after a
3433 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3434
3435<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3436<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3437
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3438</div>
3439
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3440</div>
3441
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3442<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3443<h3>
3444 <a name="binaryops">Binary Operations</a>
3445</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3446
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3447<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3448
3449<p>Binary operators are used to do most of the computation in a program. They
3450 require two operands of the same type, execute an operation on them, and
3451 produce a single value. The operands might represent multiple data, as is
3452 the case with the <a href="#t_vector">vector</a> data type. The result value
3453 has the same type as its operands.</p>
3454
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3455<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3456
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3457<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3458<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3459 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3460</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3461
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3462<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3463
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3464<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3465<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3466 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3467 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3468 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3469 &lt;result&gt; = add nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3470</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3471
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3472<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3473<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3474
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3475<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3476<p>The two arguments to the '<tt>add</tt>' instruction must
3477 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3478 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3479
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3480<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3481<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3482
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3483<p>If the sum has unsigned overflow, the result returned is the mathematical
3484 result modulo 2<sup>n</sup>, where n is the bit width of the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3485
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3486<p>Because LLVM integers use a two's complement representation, this instruction
3487 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3488
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3489<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3490 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3491 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3492 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3493 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3494
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3495<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3496<pre>
3497 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3498</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3499
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3500</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3501
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3502<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3503<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3504 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3505</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3506
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3507<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3508
3509<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3510<pre>
3511 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3512</pre>
3513
3514<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3515<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3516
3517<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3518<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3519 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3520 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3521
3522<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3523<p>The value produced is the floating point sum of the two operands.</p>
3524
3525<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3526<pre>
3527 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3528</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3529
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3530</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3531
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3532<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3533<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3534 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3535</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3536
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3537<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3538
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3539<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3540<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3541 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3542 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3543 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3544 &lt;result&gt; = sub nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3545</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3546
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3547<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3548<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3549 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3550
3551<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3552 '<tt>neg</tt>' instruction present in most other intermediate
3553 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3554
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3555<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3556<p>The two arguments to the '<tt>sub</tt>' instruction must
3557 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3558 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3559
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3560<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3561<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3562
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3563<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3564 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3565 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3566
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3567<p>Because LLVM integers use a two's complement representation, this instruction
3568 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3569
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3570<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3571 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3572 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3573 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3574 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3575
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3576<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3577<pre>
3578 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3579 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3580</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3581
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3582</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3583
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3584<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3585<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3586 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3587</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3588
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3589<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3590
3591<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3592<pre>
3593 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3594</pre>
3595
3596<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3597<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3598 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3599
3600<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3601 '<tt>fneg</tt>' instruction present in most other intermediate
3602 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3603
3604<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3605<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3606 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3607 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3608
3609<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3610<p>The value produced is the floating point difference of the two operands.</p>
3611
3612<h5>Example:</h5>
3613<pre>
3614 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3615 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3616</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3617
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3618</div>
3619
3620<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3621<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3622 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3623</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3624
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3625<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3626
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3627<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3628<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3629 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3630 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3631 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3632 &lt;result&gt; = mul nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3633</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3634
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3635<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3636<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3637
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3638<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3639<p>The two arguments to the '<tt>mul</tt>' instruction must
3640 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3641 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3642
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3643<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3644<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3645
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3646<p>If the result of the multiplication has unsigned overflow, the result
3647 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3648 width of the result.</p>
3649
3650<p>Because LLVM integers use a two's complement representation, and the result
3651 is the same width as the operands, this instruction returns the correct
3652 result for both signed and unsigned integers. If a full product
3653 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3654 be sign-extended or zero-extended as appropriate to the width of the full
3655 product.</p>
3656
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3657<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3658 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3659 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3660 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3661 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3662
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3663<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3664<pre>
3665 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3666</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3667
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3668</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3669
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3670<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3671<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3672 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3673</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3674
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3675<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3676
3677<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3678<pre>
3679 &lt;result&gt; = fmul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3680</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3681
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3682<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3683<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3684
3685<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3686<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3687 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3688 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3689
3690<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3691<p>The value produced is the floating point product of the two operands.</p>
3692
3693<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3694<pre>
3695 &lt;result&gt; = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3696</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3697
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3698</div>
3699
3700<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3701<h4>
3702 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3703</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3704
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3705<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3706
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3707<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3708<pre>
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3709 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3710 &lt;result&gt; = udiv exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3711</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3712
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3713<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3714<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3715
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3716<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3717<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3718 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3719 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3720
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3721<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3722<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3723
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3724<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3725 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3726
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3727<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3728
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3729<p>If the <tt>exact</tt> keyword is present, the result value of the
3730 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3731 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3732
3733
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3734<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3735<pre>
3736 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3737</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3738
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3739</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3740
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3741<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3742<h4>
3743 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3744</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3745
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3746<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3747
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3748<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3749<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3750 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3751 &lt;result&gt; = sdiv exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3752</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3753
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3754<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3755<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3756
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3757<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3758<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3759 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3760 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3761
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3762<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3763<p>The value produced is the signed integer quotient of the two operands rounded
3764 towards zero.</p>
3765
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3766<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3767 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3768
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3769<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3770 undefined behavior; this is a rare case, but can occur, for example, by doing
3771 a 32-bit division of -2147483648 by -1.</p>
3772
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3773<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]3774 <tt>sdiv</tt> is a <a href="#trapvalues">trap value</a> if the result would
Dan Gohman38da9272010-07-11 00:08:34 +0000[diff] [blame]3775 be rounded.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3776
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3777<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3778<pre>
3779 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3780</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3781
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3782</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3783
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3784<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3785<h4>
3786 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3787</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3788
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3789<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3790
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3791<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3792<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3793 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3794</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3795
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3796<h5>Overview:</h5>
3797<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3798
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3799<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3800<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3801 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3802 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3803
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3804<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3805<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3806
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3807<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3808<pre>
3809 &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3810</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3811
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3812</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3813
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3814<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3815<h4>
3816 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3817</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3818
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3819<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3820
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3821<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3822<pre>
3823 &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3824</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3825
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3826<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3827<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3828 division of its two arguments.</p>
3829
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3830<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3831<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3832 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3833 values. Both arguments must have identical types.</p>
3834
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3835<h5>Semantics:</h5>
3836<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3837 This instruction always performs an unsigned division to get the
3838 remainder.</p>
3839
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3840<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3841 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3842
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3843<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3844
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3845<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3846<pre>
3847 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3848</pre>
3849
3850</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3851
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3852<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3853<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3854 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3855</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3856
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3857<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3858
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3859<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3860<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3861 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3862</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3863
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3864<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3865<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3866 division of its two operands. This instruction can also take
3867 <a href="#t_vector">vector</a> versions of the values in which case the
3868 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3869
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3870<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3871<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3872 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3873 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3874
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3875<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3876<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sandsdea3a5e2011-03-07 09:12:24 +0000[diff] [blame]3877 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3878 <i>modulo</i> operator (where the result is either zero or has the same sign
3879 as the divisor, <tt>op2</tt>) of a value.
3880 For more information about the difference,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3881 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3882 Math Forum</a>. For a table of how this is implemented in various languages,
3883 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3884 Wikipedia: modulo operation</a>.</p>
3885
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3886<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3887 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3888
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3889<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3890 Overflow also leads to undefined behavior; this is a rare case, but can
3891 occur, for example, by taking the remainder of a 32-bit division of
3892 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3893 lets srem be implemented using instructions that return both the result of
3894 the division and the remainder.)</p>
3895
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3896<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3897<pre>
3898 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3899</pre>
3900
3901</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3902
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3903<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3904<h4>
3905 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3906</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3907
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3908<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3909
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3910<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3911<pre>
3912 &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3913</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3914
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3915<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3916<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3917 its two operands.</p>
3918
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3919<h5>Arguments:</h5>
3920<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3921 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3922 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3923
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3924<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3925<p>This instruction returns the <i>remainder</i> of a division. The remainder
3926 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3927
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3928<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3929<pre>
3930 &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3931</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3932
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3933</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3934
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3935</div>
3936
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3937<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3938<h3>
3939 <a name="bitwiseops">Bitwise Binary Operations</a>
3940</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3941
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3942<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3943
3944<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3945 program. They are generally very efficient instructions and can commonly be
3946 strength reduced from other instructions. They require two operands of the
3947 same type, execute an operation on them, and produce a single value. The
3948 resulting value is the same type as its operands.</p>
3949
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3950<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3951<h4>
3952 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3953</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3954
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3955<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3956
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3957<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3958<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3959 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3960 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3961 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3962 &lt;result&gt; = shl nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3963</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3964
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3965<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3966<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3967 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3968
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3969<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3970<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3971 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3972 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3973
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3974<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3975<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3976 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3977 is (statically or dynamically) negative or equal to or larger than the number
3978 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3979 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3980 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3981
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3982<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3983 <a href="#trapvalues">trap value</a> if it shifts out any non-zero bits. If
Chris Lattner66298c12011-02-09 16:44:44 +0000[diff] [blame]3984 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3985 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3986 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3987 they would if the shift were expressed as a mul instruction with the same
3988 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3989
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3990<h5>Example:</h5>
3991<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3992 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3993 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3994 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3995 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3996 &lt;result&gt; = shl &lt;2 x i32&gt; &lt; i32 1, i32 1&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 2, i32 4&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3997</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3998
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3999</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4000
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4001<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4002<h4>
4003 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
4004</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4005
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4006<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4007
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4008<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4009<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4010 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4011 &lt;result&gt; = lshr exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4012</pre>
4013
4014<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4015<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
4016 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4017
4018<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4019<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4020 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4021 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4022
4023<h5>Semantics:</h5>
4024<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4025 significant bits of the result will be filled with zero bits after the shift.
4026 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
4027 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
4028 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
4029 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4030
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4031<p>If the <tt>exact</tt> keyword is present, the result value of the
4032 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4033 shifted out are non-zero.</p>
4034
4035
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4036<h5>Example:</h5>
4037<pre>
4038 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
4039 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
4040 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
4041 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4042 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]4043 &lt;result&gt; = lshr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0x7FFFFFFF, i32 1&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4044</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4045
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4046</div>
4047
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]4048<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4049<h4>
4050 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
4051</h4>
4052
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4053<div>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4054
4055<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4056<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4057 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4058 &lt;result&gt; = ashr exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4059</pre>
4060
4061<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4062<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
4063 operand shifted to the right a specified number of bits with sign
4064 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4065
4066<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4067<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4068 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4069 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4070
4071<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4072<p>This instruction always performs an arithmetic shift right operation, The
4073 most significant bits of the result will be filled with the sign bit
4074 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
4075 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
4076 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
4077 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4078
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4079<p>If the <tt>exact</tt> keyword is present, the result value of the
4080 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4081 shifted out are non-zero.</p>
4082
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4083<h5>Example:</h5>
4084<pre>
4085 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
4086 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
4087 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
4088 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4089 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]4090 &lt;result&gt; = ashr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 3&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 -1, i32 0&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4091</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4092
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4093</div>
4094
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4095<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4096<h4>
4097 <a name="i_and">'<tt>and</tt>' Instruction</a>
4098</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4099
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4100<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4101
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4102<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4103<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4104 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4105</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4106
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4107<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4108<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
4109 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4110
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4111<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4112<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4113 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4114 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4115
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4116<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4117<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4118
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4119<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4120 <tbody>
4121 <tr>
4122 <td>In0</td>
4123 <td>In1</td>
4124 <td>Out</td>
4125 </tr>
4126 <tr>
4127 <td>0</td>
4128 <td>0</td>
4129 <td>0</td>
4130 </tr>
4131 <tr>
4132 <td>0</td>
4133 <td>1</td>
4134 <td>0</td>
4135 </tr>
4136 <tr>
4137 <td>1</td>
4138 <td>0</td>
4139 <td>0</td>
4140 </tr>
4141 <tr>
4142 <td>1</td>
4143 <td>1</td>
4144 <td>1</td>
4145 </tr>
4146 </tbody>
4147</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4148
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4149<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4150<pre>
4151 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4152 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
4153 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4154</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4155</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4156<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4157<h4>
4158 <a name="i_or">'<tt>or</tt>' Instruction</a>
4159</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4160
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4161<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4162
4163<h5>Syntax:</h5>
4164<pre>
4165 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4166</pre>
4167
4168<h5>Overview:</h5>
4169<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4170 two operands.</p>
4171
4172<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4173<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4174 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4175 values. Both arguments must have identical types.</p>
4176
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4177<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4178<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4179
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4180<table border="1" cellspacing="0" cellpadding="4">
4181 <tbody>
4182 <tr>
4183 <td>In0</td>
4184 <td>In1</td>
4185 <td>Out</td>
4186 </tr>
4187 <tr>
4188 <td>0</td>
4189 <td>0</td>
4190 <td>0</td>
4191 </tr>
4192 <tr>
4193 <td>0</td>
4194 <td>1</td>
4195 <td>1</td>
4196 </tr>
4197 <tr>
4198 <td>1</td>
4199 <td>0</td>
4200 <td>1</td>
4201 </tr>
4202 <tr>
4203 <td>1</td>
4204 <td>1</td>
4205 <td>1</td>
4206 </tr>
4207 </tbody>
4208</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4209
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4210<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4211<pre>
4212 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4213 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4214 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4215</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4216
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4217</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4218
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4219<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4220<h4>
4221 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4222</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4223
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4224<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4225
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4226<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4227<pre>
4228 &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4229</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4230
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4231<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4232<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4233 its two operands. The <tt>xor</tt> is used to implement the "one's
4234 complement" operation, which is the "~" operator in C.</p>
4235
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4236<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4237<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4238 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4239 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4240
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4241<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4242<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4243
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4244<table border="1" cellspacing="0" cellpadding="4">
4245 <tbody>
4246 <tr>
4247 <td>In0</td>
4248 <td>In1</td>
4249 <td>Out</td>
4250 </tr>
4251 <tr>
4252 <td>0</td>
4253 <td>0</td>
4254 <td>0</td>
4255 </tr>
4256 <tr>
4257 <td>0</td>
4258 <td>1</td>
4259 <td>1</td>
4260 </tr>
4261 <tr>
4262 <td>1</td>
4263 <td>0</td>
4264 <td>1</td>
4265 </tr>
4266 <tr>
4267 <td>1</td>
4268 <td>1</td>
4269 <td>0</td>
4270 </tr>
4271 </tbody>
4272</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4273
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4274<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4275<pre>
4276 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4277 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4278 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4279 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4280</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4281
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4282</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4283
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4284</div>
4285
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4286<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4287<h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4288 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4289</h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4290
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4291<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4292
4293<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4294 target-independent manner. These instructions cover the element-access and
4295 vector-specific operations needed to process vectors effectively. While LLVM
4296 does directly support these vector operations, many sophisticated algorithms
4297 will want to use target-specific intrinsics to take full advantage of a
4298 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4299
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4300<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4301<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4302 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4303</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4304
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4305<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4306
4307<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4308<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4309 &lt;result&gt; = extractelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, i32 &lt;idx&gt; <i>; yields &lt;ty&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4310</pre>
4311
4312<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4313<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4314 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4315
4316
4317<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4318<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4319 of <a href="#t_vector">vector</a> type. The second operand is an index
4320 indicating the position from which to extract the element. The index may be
4321 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4322
4323<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4324<p>The result is a scalar of the same type as the element type of
4325 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4326 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4327 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4328
4329<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4330<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4331 &lt;result&gt; = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4332</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4333
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4334</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4335
4336<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4337<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4338 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4339</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4340
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4341<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4342
4343<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4344<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]4345 &lt;result&gt; = insertelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, i32 &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4346</pre>
4347
4348<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4349<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4350 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4351
4352<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4353<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4354 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4355 whose type must equal the element type of the first operand. The third
4356 operand is an index indicating the position at which to insert the value.
4357 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4358
4359<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4360<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4361 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4362 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4363 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4364
4365<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4366<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4367 &lt;result&gt; = insertelement &lt;4 x i32&gt; %vec, i32 1, i32 0 <i>; yields &lt;4 x i32&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4368</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4369
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4370</div>
4371
4372<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4373<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4374 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4375</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4376
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4377<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4378
4379<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4380<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4381 &lt;result&gt; = shufflevector &lt;n x &lt;ty&gt;&gt; &lt;v1&gt;, &lt;n x &lt;ty&gt;&gt; &lt;v2&gt;, &lt;m x i32&gt; &lt;mask&gt; <i>; yields &lt;m x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4382</pre>
4383
4384<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4385<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4386 from two input vectors, returning a vector with the same element type as the
4387 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4388
4389<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4390<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4391 with types that match each other. The third argument is a shuffle mask whose
4392 element type is always 'i32'. The result of the instruction is a vector
4393 whose length is the same as the shuffle mask and whose element type is the
4394 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4395
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4396<p>The shuffle mask operand is required to be a constant vector with either
4397 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4398
4399<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4400<p>The elements of the two input vectors are numbered from left to right across
4401 both of the vectors. The shuffle mask operand specifies, for each element of
4402 the result vector, which element of the two input vectors the result element
4403 gets. The element selector may be undef (meaning "don't care") and the
4404 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4405
4406<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4407<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4408 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4409 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4410 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4411 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4412 &lt;result&gt; = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4413 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4414 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4415 &lt;8 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 &gt; <i>; yields &lt;8 x i32&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4416</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4417
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4418</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]4419
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4420</div>
4421
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4422<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4423<h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4424 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4425</h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4426
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4427<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4428
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4429<p>LLVM supports several instructions for working with
4430 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4431
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4432<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4433<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4434 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4435</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4436
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4437<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4438
4439<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4440<pre>
4441 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4442</pre>
4443
4444<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4445<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4446 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4447
4448<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4449<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4450 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4451 <a href="#t_array">array</a> type. The operands are constant indices to
4452 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4453 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4454 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4455 <ul>
4456 <li>Since the value being indexed is not a pointer, the first index is
4457 omitted and assumed to be zero.</li>
4458 <li>At least one index must be specified.</li>
4459 <li>Not only struct indices but also array indices must be in
4460 bounds.</li>
4461 </ul>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4462
4463<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4464<p>The result is the value at the position in the aggregate specified by the
4465 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4466
4467<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4468<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4469 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4470</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4471
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4472</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4473
4474<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4475<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4476 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4477</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4478
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4479<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4480
4481<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4482<pre>
Bill Wendling194229e2011-07-26 20:42:28 +0000[diff] [blame]4483 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt;{, &lt;idx&gt;}* <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4484</pre>
4485
4486<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4487<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4488 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4489
4490<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4491<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4492 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4493 <a href="#t_array">array</a> type. The second operand is a first-class
4494 value to insert. The following operands are constant indices indicating
4495 the position at which to insert the value in a similar manner as indices in a
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4496 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4497 value to insert must have the same type as the value identified by the
4498 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4499
4500<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4501<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4502 that of <tt>val</tt> except that the value at the position specified by the
4503 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4504
4505<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4506<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame]4507 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4508 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4509 %agg3 = insertvalue {i32, {float}} %agg1, float %val, 1, 0 <i>; yields {i32 1, float %val}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4510</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4511
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4512</div>
4513
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4514</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4515
4516<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4517<h3>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4518 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4519</h3>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4520
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4521<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4522
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4523<p>A key design point of an SSA-based representation is how it represents
4524 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4525 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4526 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4527
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4528<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4529<h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4530 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4531</h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4532
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4533<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4534
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4535<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4536<pre>
Dan Gohmanf75a7d32010-05-28 01:14:11 +0000[diff] [blame]4537 &lt;result&gt; = alloca &lt;type&gt;[, &lt;ty&gt; &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4538</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4539
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4540<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4541<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4542 currently executing function, to be automatically released when this function
4543 returns to its caller. The object is always allocated in the generic address
4544 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4545
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4546<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4547<p>The '<tt>alloca</tt>' instruction
4548 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4549 runtime stack, returning a pointer of the appropriate type to the program.
4550 If "NumElements" is specified, it is the number of elements allocated,
4551 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4552 specified, the value result of the allocation is guaranteed to be aligned to
4553 at least that boundary. If not specified, or if zero, the target can choose
4554 to align the allocation on any convenient boundary compatible with the
4555 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4556
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4557<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4558
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4559<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4560<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4561 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4562 memory is automatically released when the function returns. The
4563 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4564 variables that must have an address available. When the function returns
4565 (either with the <tt><a href="#i_ret">ret</a></tt>
4566 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4567 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4568
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4569<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4570<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4571 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4572 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4573 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4574 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4575</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4576
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4577</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4578
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4579<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4580<h4>
4581 <a name="i_load">'<tt>load</tt>' Instruction</a>
4582</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4583
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4584<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4585
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4586<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4587<pre>
Eli Friedmanf03bb262011-08-12 22:50:01 +0000[diff] [blame]4588 &lt;result&gt; = load [volatile] &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4589 &lt;result&gt; = load atomic [volatile] &lt;ty&gt;* &lt;pointer&gt; [singlethread] &lt;ordering&gt;, align &lt;alignment&gt;
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4590 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4591</pre>
4592
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4593<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4594<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4595
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4596<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4597<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4598 from which to load. The pointer must point to
4599 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4600 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4601 number or order of execution of this <tt>load</tt> with other <a
4602 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4603
Eli Friedman21006d42011-08-09 23:02:53 +0000[diff] [blame]4604<p>If the <code>load</code> is marked as <code>atomic</code>, it takes an extra
4605 <a href="#ordering">ordering</a> and optional <code>singlethread</code>
4606 argument. The <code>release</code> and <code>acq_rel</code> orderings are
4607 not valid on <code>load</code> instructions. Atomic loads produce <a
4608 href="#memorymodel">defined</a> results when they may see multiple atomic
4609 stores. The type of the pointee must be an integer type whose bit width
4610 is a power of two greater than or equal to eight and less than or equal
4611 to a target-specific size limit. <code>align</code> must be explicitly
4612 specified on atomic loads, and the load has undefined behavior if the
4613 alignment is not set to a value which is at least the size in bytes of
4614 the pointee. <code>!nontemporal</code> does not have any defined semantics
4615 for atomic loads.</p>
4616
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4617<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4618 operation (that is, the alignment of the memory address). A value of 0 or an
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4619 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4620 alignment for the target. It is the responsibility of the code emitter to
4621 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4622 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4623 produce less efficient code. An alignment of 1 is always safe.</p>
4624
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4625<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4626 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4627 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4628 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4629 and code generator that this load is not expected to be reused in the cache.
4630 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4631 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4632
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4633<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4634<p>The location of memory pointed to is loaded. If the value being loaded is of
4635 scalar type then the number of bytes read does not exceed the minimum number
4636 of bytes needed to hold all bits of the type. For example, loading an
4637 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4638 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4639 is undefined if the value was not originally written using a store of the
4640 same type.</p>
4641
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4642<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4643<pre>
4644 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4645 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4646 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4647</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4648
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4649</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4650
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4651<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4652<h4>
4653 <a name="i_store">'<tt>store</tt>' Instruction</a>
4654</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4655
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4656<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4657
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4658<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4659<pre>
Eli Friedmanf03bb262011-08-12 22:50:01 +0000[diff] [blame]4660 store [volatile] &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
4661 store atomic [volatile] &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt; [singlethread] &lt;ordering&gt;, align &lt;alignment&gt; <i>; yields {void}</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4662</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4663
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4664<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4665<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4666
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4667<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4668<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4669 and an address at which to store it. The type of the
4670 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4671 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4672 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4673 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4674 order of execution of this <tt>store</tt> with other <a
4675 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4676
Eli Friedman21006d42011-08-09 23:02:53 +0000[diff] [blame]4677<p>If the <code>store</code> is marked as <code>atomic</code>, it takes an extra
4678 <a href="#ordering">ordering</a> and optional <code>singlethread</code>
4679 argument. The <code>acquire</code> and <code>acq_rel</code> orderings aren't
4680 valid on <code>store</code> instructions. Atomic loads produce <a
4681 href="#memorymodel">defined</a> results when they may see multiple atomic
4682 stores. The type of the pointee must be an integer type whose bit width
4683 is a power of two greater than or equal to eight and less than or equal
4684 to a target-specific size limit. <code>align</code> must be explicitly
4685 specified on atomic stores, and the store has undefined behavior if the
4686 alignment is not set to a value which is at least the size in bytes of
4687 the pointee. <code>!nontemporal</code> does not have any defined semantics
4688 for atomic stores.</p>
4689
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4690<p>The optional constant "align" argument specifies the alignment of the
4691 operation (that is, the alignment of the memory address). A value of 0 or an
4692 omitted "align" argument means that the operation has the preferential
4693 alignment for the target. It is the responsibility of the code emitter to
4694 ensure that the alignment information is correct. Overestimating the
4695 alignment results in an undefined behavior. Underestimating the alignment may
4696 produce less efficient code. An alignment of 1 is always safe.</p>
4697
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4698<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4699 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4700 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4701 instruction tells the optimizer and code generator that this load is
4702 not expected to be reused in the cache. The code generator may
4703 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4704 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4705
4706
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4707<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4708<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4709 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4710 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4711 does not exceed the minimum number of bytes needed to hold all bits of the
4712 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4713 writing a value of a type like <tt>i20</tt> with a size that is not an
4714 integral number of bytes, it is unspecified what happens to the extra bits
4715 that do not belong to the type, but they will typically be overwritten.</p>
4716
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4717<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4718<pre>
4719 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4720 store i32 3, i32* %ptr <i>; yields {void}</i>
4721 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4722</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4723
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4724</div>
4725
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4726<!-- _______________________________________________________________________ -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4727<h4>
4728<a name="i_fence">'<tt>fence</tt>' Instruction</a>
4729</h4>
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame]4730
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4731<div>
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame]4732
4733<h5>Syntax:</h5>
4734<pre>
4735 fence [singlethread] &lt;ordering&gt; <i>; yields {void}</i>
4736</pre>
4737
4738<h5>Overview:</h5>
4739<p>The '<tt>fence</tt>' instruction is used to introduce happens-before edges
4740between operations.</p>
4741
4742<h5>Arguments:</h5> <p>'<code>fence</code>' instructions take an <a
4743href="#ordering">ordering</a> argument which defines what
4744<i>synchronizes-with</i> edges they add. They can only be given
4745<code>acquire</code>, <code>release</code>, <code>acq_rel</code>, and
4746<code>seq_cst</code> orderings.</p>
4747
4748<h5>Semantics:</h5>
4749<p>A fence <var>A</var> which has (at least) <code>release</code> ordering
4750semantics <i>synchronizes with</i> a fence <var>B</var> with (at least)
4751<code>acquire</code> ordering semantics if and only if there exist atomic
4752operations <var>X</var> and <var>Y</var>, both operating on some atomic object
4753<var>M</var>, such that <var>A</var> is sequenced before <var>X</var>,
4754<var>X</var> modifies <var>M</var> (either directly or through some side effect
4755of a sequence headed by <var>X</var>), <var>Y</var> is sequenced before
4756<var>B</var>, and <var>Y</var> observes <var>M</var>. This provides a
4757<i>happens-before</i> dependency between <var>A</var> and <var>B</var>. Rather
4758than an explicit <code>fence</code>, one (but not both) of the atomic operations
4759<var>X</var> or <var>Y</var> might provide a <code>release</code> or
4760<code>acquire</code> (resp.) ordering constraint and still
4761<i>synchronize-with</i> the explicit <code>fence</code> and establish the
4762<i>happens-before</i> edge.</p>
4763
4764<p>A <code>fence</code> which has <code>seq_cst</code> ordering, in addition to
4765having both <code>acquire</code> and <code>release</code> semantics specified
4766above, participates in the global program order of other <code>seq_cst</code>
4767operations and/or fences.</p>
4768
4769<p>The optional "<a href="#singlethread"><code>singlethread</code></a>" argument
4770specifies that the fence only synchronizes with other fences in the same
4771thread. (This is useful for interacting with signal handlers.)</p>
4772
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame]4773<h5>Example:</h5>
4774<pre>
4775 fence acquire <i>; yields {void}</i>
4776 fence singlethread seq_cst <i>; yields {void}</i>
4777</pre>
4778
4779</div>
4780
4781<!-- _______________________________________________________________________ -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4782<h4>
4783<a name="i_cmpxchg">'<tt>cmpxchg</tt>' Instruction</a>
4784</h4>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4785
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4786<div>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4787
4788<h5>Syntax:</h5>
4789<pre>
Eli Friedmanf03bb262011-08-12 22:50:01 +0000[diff] [blame]4790 cmpxchg [volatile] &lt;ty&gt;* &lt;pointer&gt;, &lt;ty&gt; &lt;cmp&gt;, &lt;ty&gt; &lt;new&gt; [singlethread] &lt;ordering&gt; <i>; yields {ty}</i>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4791</pre>
4792
4793<h5>Overview:</h5>
4794<p>The '<tt>cmpxchg</tt>' instruction is used to atomically modify memory.
4795It loads a value in memory and compares it to a given value. If they are
4796equal, it stores a new value into the memory.</p>
4797
4798<h5>Arguments:</h5>
4799<p>There are three arguments to the '<code>cmpxchg</code>' instruction: an
4800address to operate on, a value to compare to the value currently be at that
4801address, and a new value to place at that address if the compared values are
4802equal. The type of '<var>&lt;cmp&gt;</var>' must be an integer type whose
4803bit width is a power of two greater than or equal to eight and less than
4804or equal to a target-specific size limit. '<var>&lt;cmp&gt;</var>' and
4805'<var>&lt;new&gt;</var>' must have the same type, and the type of
4806'<var>&lt;pointer&gt;</var>' must be a pointer to that type. If the
4807<code>cmpxchg</code> is marked as <code>volatile</code>, then the
4808optimizer is not allowed to modify the number or order of execution
4809of this <code>cmpxchg</code> with other <a href="#volatile">volatile
4810operations</a>.</p>
4811
4812<!-- FIXME: Extend allowed types. -->
4813
4814<p>The <a href="#ordering"><var>ordering</var></a> argument specifies how this
4815<code>cmpxchg</code> synchronizes with other atomic operations.</p>
4816
4817<p>The optional "<code>singlethread</code>" argument declares that the
4818<code>cmpxchg</code> is only atomic with respect to code (usually signal
4819handlers) running in the same thread as the <code>cmpxchg</code>. Otherwise the
4820cmpxchg is atomic with respect to all other code in the system.</p>
4821
4822<p>The pointer passed into cmpxchg must have alignment greater than or equal to
4823the size in memory of the operand.
4824
4825<h5>Semantics:</h5>
4826<p>The contents of memory at the location specified by the
4827'<tt>&lt;pointer&gt;</tt>' operand is read and compared to
4828'<tt>&lt;cmp&gt;</tt>'; if the read value is the equal,
4829'<tt>&lt;new&gt;</tt>' is written. The original value at the location
4830is returned.
4831
4832<p>A successful <code>cmpxchg</code> is a read-modify-write instruction for the
4833purpose of identifying <a href="#release_sequence">release sequences</a>. A
4834failed <code>cmpxchg</code> is equivalent to an atomic load with an ordering
4835parameter determined by dropping any <code>release</code> part of the
4836<code>cmpxchg</code>'s ordering.</p>
4837
4838<!--
4839FIXME: Is compare_exchange_weak() necessary? (Consider after we've done
4840optimization work on ARM.)
4841
4842FIXME: Is a weaker ordering constraint on failure helpful in practice?
4843-->
4844
4845<h5>Example:</h5>
4846<pre>
4847entry:
4848 %orig = atomic <a href="#i_load">load</a> i32* %ptr unordered <i>; yields {i32}</i>
4849 <a href="#i_br">br</a> label %loop
4850
4851loop:
4852 %cmp = <a href="#i_phi">phi</a> i32 [ %orig, %entry ], [%old, %loop]
4853 %squared = <a href="#i_mul">mul</a> i32 %cmp, %cmp
4854 %old = cmpxchg i32* %ptr, i32 %cmp, i32 %squared <i>; yields {i32}</i>
4855 %success = <a href="#i_icmp">icmp</a> eq i32 %cmp, %old
4856 <a href="#i_br">br</a> i1 %success, label %done, label %loop
4857
4858done:
4859 ...
4860</pre>
4861
4862</div>
4863
4864<!-- _______________________________________________________________________ -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4865<h4>
4866<a name="i_atomicrmw">'<tt>atomicrmw</tt>' Instruction</a>
4867</h4>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4868
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4869<div>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4870
4871<h5>Syntax:</h5>
4872<pre>
Eli Friedmanf03bb262011-08-12 22:50:01 +0000[diff] [blame]4873 atomicrmw [volatile] &lt;operation&gt; &lt;ty&gt;* &lt;pointer&gt;, &lt;ty&gt; &lt;value&gt; [singlethread] &lt;ordering&gt; <i>; yields {ty}</i>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4874</pre>
4875
4876<h5>Overview:</h5>
4877<p>The '<tt>atomicrmw</tt>' instruction is used to atomically modify memory.</p>
4878
4879<h5>Arguments:</h5>
4880<p>There are three arguments to the '<code>atomicrmw</code>' instruction: an
4881operation to apply, an address whose value to modify, an argument to the
4882operation. The operation must be one of the following keywords:</p>
4883<ul>
4884 <li>xchg</li>
4885 <li>add</li>
4886 <li>sub</li>
4887 <li>and</li>
4888 <li>nand</li>
4889 <li>or</li>
4890 <li>xor</li>
4891 <li>max</li>
4892 <li>min</li>
4893 <li>umax</li>
4894 <li>umin</li>
4895</ul>
4896
4897<p>The type of '<var>&lt;value&gt;</var>' must be an integer type whose
4898bit width is a power of two greater than or equal to eight and less than
4899or equal to a target-specific size limit. The type of the
4900'<code>&lt;pointer&gt;</code>' operand must be a pointer to that type.
4901If the <code>atomicrmw</code> is marked as <code>volatile</code>, then the
4902optimizer is not allowed to modify the number or order of execution of this
4903<code>atomicrmw</code> with other <a href="#volatile">volatile
4904 operations</a>.</p>
4905
4906<!-- FIXME: Extend allowed types. -->
4907
4908<h5>Semantics:</h5>
4909<p>The contents of memory at the location specified by the
4910'<tt>&lt;pointer&gt;</tt>' operand are atomically read, modified, and written
4911back. The original value at the location is returned. The modification is
4912specified by the <var>operation</var> argument:</p>
4913
4914<ul>
4915 <li>xchg: <code>*ptr = val</code></li>
4916 <li>add: <code>*ptr = *ptr + val</code></li>
4917 <li>sub: <code>*ptr = *ptr - val</code></li>
4918 <li>and: <code>*ptr = *ptr &amp; val</code></li>
4919 <li>nand: <code>*ptr = ~(*ptr &amp; val)</code></li>
4920 <li>or: <code>*ptr = *ptr | val</code></li>
4921 <li>xor: <code>*ptr = *ptr ^ val</code></li>
4922 <li>max: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using a signed comparison)</li>
4923 <li>min: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using a signed comparison)</li>
4924 <li>umax: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4925 <li>umin: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4926</ul>
4927
4928<h5>Example:</h5>
4929<pre>
4930 %old = atomicrmw add i32* %ptr, i32 1 acquire <i>; yields {i32}</i>
4931</pre>
4932
4933</div>
4934
4935<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4936<h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4937 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4938</h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4939
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4940<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4941
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4942<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4943<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4944 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4945 &lt;result&gt; = getelementptr inbounds &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4946</pre>
4947
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4948<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4949<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4950 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4951 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4952
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4953<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4954<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4955 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4956 elements of the aggregate object are indexed. The interpretation of each
4957 index is dependent on the type being indexed into. The first index always
4958 indexes the pointer value given as the first argument, the second index
4959 indexes a value of the type pointed to (not necessarily the value directly
4960 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4961 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4962 vectors, and structs. Note that subsequent types being indexed into
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4963 can never be pointers, since that would require loading the pointer before
4964 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4965
4966<p>The type of each index argument depends on the type it is indexing into.
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4967 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4968 integer <b>constants</b> are allowed. When indexing into an array, pointer
4969 or vector, integers of any width are allowed, and they are not required to be
Eli Friedman266246c2011-08-12 23:37:55 +0000[diff] [blame]4970 constant. These integers are treated as signed values where relevant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4971
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4972<p>For example, let's consider a C code fragment and how it gets compiled to
4973 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4974
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4975<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4976struct RT {
4977 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4978 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4979 char C;
4980};
4981struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4982 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4983 double Y;
4984 struct RT Z;
4985};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4986
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4987int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4988 return &amp;s[1].Z.B[5][13];
4989}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4990</pre>
4991
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4992<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4993
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4994<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]4995%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4996%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4997
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4998define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4999entry:
5000 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
5001 ret i32* %reg
5002}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5003</pre>
5004
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]5005<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5006<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5007 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
5008 }</tt>' type, a structure. The second index indexes into the third element
5009 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
5010 i8 }</tt>' type, another structure. The third index indexes into the second
5011 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
5012 array. The two dimensions of the array are subscripted into, yielding an
5013 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
5014 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5015
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5016<p>Note that it is perfectly legal to index partially through a structure,
5017 returning a pointer to an inner element. Because of this, the LLVM code for
5018 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5019
5020<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]5021 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5022 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]5023 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
5024 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5025 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
5026 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
5027 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5028 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5029</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]5030
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]5031<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]5032 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
5033 base pointer is not an <i>in bounds</i> address of an allocated object,
5034 or if any of the addresses that would be formed by successive addition of
5035 the offsets implied by the indices to the base address with infinitely
Eli Friedman266246c2011-08-12 23:37:55 +0000[diff] [blame]5036 precise signed arithmetic are not an <i>in bounds</i> address of that
5037 allocated object. The <i>in bounds</i> addresses for an allocated object
5038 are all the addresses that point into the object, plus the address one
5039 byte past the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]5040
5041<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
Eli Friedman266246c2011-08-12 23:37:55 +0000[diff] [blame]5042 the base address with silently-wrapping two's complement arithmetic. If the
5043 offsets have a different width from the pointer, they are sign-extended or
5044 truncated to the width of the pointer. The result value of the
5045 <tt>getelementptr</tt> may be outside the object pointed to by the base
5046 pointer. The result value may not necessarily be used to access memory
5047 though, even if it happens to point into allocated storage. See the
5048 <a href="#pointeraliasing">Pointer Aliasing Rules</a> section for more
5049 information.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]5050
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5051<p>The getelementptr instruction is often confusing. For some more insight into
5052 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]5053
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]5054<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5055<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5056 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]5057 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
5058 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5059 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]5060 <i>; yields i8*:eptr</i>
5061 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]5062 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]5063 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5064</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5065
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5066</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]5067
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5068</div>
5069
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5070<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5071<h3>
5072 <a name="convertops">Conversion Operations</a>
5073</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5074
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5075<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5076
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5077<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5078 which all take a single operand and a type. They perform various bit
5079 conversions on the operand.</p>
5080
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5081<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5082<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5083 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5084</h4>
5085
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5086<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5087
5088<h5>Syntax:</h5>
5089<pre>
5090 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5091</pre>
5092
5093<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5094<p>The '<tt>trunc</tt>' instruction truncates its operand to the
5095 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5096
5097<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5098<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
5099 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5100 of the same number of integers.
5101 The bit size of the <tt>value</tt> must be larger than
5102 the bit size of the destination type, <tt>ty2</tt>.
5103 Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5104
5105<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5106<p>The '<tt>trunc</tt>' instruction truncates the high order bits
5107 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
5108 source size must be larger than the destination size, <tt>trunc</tt> cannot
5109 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5110
5111<h5>Example:</h5>
5112<pre>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5113 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
5114 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
5115 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
5116 %W = trunc &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i8&gt; <i>; yields &lt;i8 8, i8 7&gt;</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5117</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5118
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5119</div>
5120
5121<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5122<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5123 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5124</h4>
5125
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5126<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5127
5128<h5>Syntax:</h5>
5129<pre>
5130 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5131</pre>
5132
5133<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5134<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5135 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5136
5137
5138<h5>Arguments:</h5>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]5139<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
5140 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5141 of the same number of integers.
5142 The bit size of the <tt>value</tt> must be smaller than
5143 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5144 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5145
5146<h5>Semantics:</h5>
5147<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5148 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5149
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]5150<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5151
5152<h5>Example:</h5>
5153<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5154 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5155 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]5156 %Z = zext &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i32&gt; <i>; yields &lt;i32 8, i32 7&gt;</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5157</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5158
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5159</div>
5160
5161<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5162<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5163 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5164</h4>
5165
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5166<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5167
5168<h5>Syntax:</h5>
5169<pre>
5170 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5171</pre>
5172
5173<h5>Overview:</h5>
5174<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
5175
5176<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5177<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
5178 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5179 of the same number of integers.
5180 The bit size of the <tt>value</tt> must be smaller than
5181 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5182 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5183
5184<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5185<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
5186 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
5187 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5188
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5189<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5190
5191<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5192<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5193 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5194 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5195 %Z = sext &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i32&gt; <i>; yields &lt;i32 8, i32 7&gt;</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5196</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5197
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5198</div>
5199
5200<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5201<h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5202 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5203</h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5204
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5205<div>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5206
5207<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5208<pre>
5209 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5210</pre>
5211
5212<h5>Overview:</h5>
5213<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5214 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5215
5216<h5>Arguments:</h5>
5217<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5218 point</a> value to cast and a <a href="#t_floating">floating point</a> type
5219 to cast it to. The size of <tt>value</tt> must be larger than the size of
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5220 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5221 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5222
5223<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5224<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5225 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5226 <a href="#t_floating">floating point</a> type. If the value cannot fit
5227 within the destination type, <tt>ty2</tt>, then the results are
5228 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5229
5230<h5>Example:</h5>
5231<pre>
5232 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
5233 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
5234</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5235
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5236</div>
5237
5238<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5239<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5240 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5241</h4>
5242
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5243<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5244
5245<h5>Syntax:</h5>
5246<pre>
5247 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5248</pre>
5249
5250<h5>Overview:</h5>
5251<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5252 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5253
5254<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5255<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5256 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
5257 a <a href="#t_floating">floating point</a> type to cast it to. The source
5258 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5259
5260<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5261<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5262 <a href="#t_floating">floating point</a> type to a larger
5263 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
5264 used to make a <i>no-op cast</i> because it always changes bits. Use
5265 <tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5266
5267<h5>Example:</h5>
5268<pre>
Nick Lewycky5bb3ece2011-03-31 18:20:19 +0000[diff] [blame]5269 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
5270 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5271</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5272
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5273</div>
5274
5275<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5276<h4>
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]5277 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5278</h4>
5279
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5280<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5281
5282<h5>Syntax:</h5>
5283<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5284 &lt;result&gt; = fptoui &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5285</pre>
5286
5287<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5288<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5289 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5290
5291<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5292<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
5293 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5294 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5295 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5296 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5297
5298<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5299<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5300 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5301 towards zero) unsigned integer value. If the value cannot fit
5302 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5303
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5304<h5>Example:</h5>
5305<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5306 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]5307 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5308 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5309</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5310
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5311</div>
5312
5313<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5314<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5315 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5316</h4>
5317
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5318<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5319
5320<h5>Syntax:</h5>
5321<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5322 &lt;result&gt; = fptosi &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5323</pre>
5324
5325<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5326<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5327 <a href="#t_floating">floating point</a> <tt>value</tt> to
5328 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5329
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5330<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5331<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
5332 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5333 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5334 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5335 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5336
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5337<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5338<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5339 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5340 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
5341 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5342
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]5343<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5344<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5345 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]5346 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5347 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5348</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5349
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5350</div>
5351
5352<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5353<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5354 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5355</h4>
5356
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5357<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5358
5359<h5>Syntax:</h5>
5360<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5361 &lt;result&gt; = uitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5362</pre>
5363
5364<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5365<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5366 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5367
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5368<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5369<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5370 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5371 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5372 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5373 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5374
5375<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5376<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5377 integer quantity and converts it to the corresponding floating point
5378 value. If the value cannot fit in the floating point value, the results are
5379 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5380
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5381<h5>Example:</h5>
5382<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5383 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5384 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5385</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5386
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5387</div>
5388
5389<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5390<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5391 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5392</h4>
5393
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5394<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5395
5396<h5>Syntax:</h5>
5397<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5398 &lt;result&gt; = sitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5399</pre>
5400
5401<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5402<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5403 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5404
5405<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5406<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5407 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5408 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5409 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5410 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5411
5412<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5413<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5414 quantity and converts it to the corresponding floating point value. If the
5415 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5416
5417<h5>Example:</h5>
5418<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5419 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5420 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5421</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5422
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5423</div>
5424
5425<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5426<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5427 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5428</h4>
5429
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5430<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5431
5432<h5>Syntax:</h5>
5433<pre>
5434 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5435</pre>
5436
5437<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5438<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5439 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5440
5441<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5442<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5443 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5444 <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5445
5446<h5>Semantics:</h5>
5447<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5448 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5449 truncating or zero extending that value to the size of the integer type. If
5450 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5451 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5452 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5453 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5454
5455<h5>Example:</h5>
5456<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5457 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5458 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5459</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5460
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5461</div>
5462
5463<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5464<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5465 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5466</h4>
5467
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5468<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5469
5470<h5>Syntax:</h5>
5471<pre>
5472 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5473</pre>
5474
5475<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5476<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5477 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5478
5479<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]5480<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5481 value to cast, and a type to cast it to, which must be a
5482 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5483
5484<h5>Semantics:</h5>
5485<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5486 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5487 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5488 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5489 than the size of a pointer then a zero extension is done. If they are the
5490 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5491
5492<h5>Example:</h5>
5493<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5494 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5495 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5496 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5497</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5498
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5499</div>
5500
5501<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5502<h4>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5503 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5504</h4>
5505
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5506<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5507
5508<h5>Syntax:</h5>
5509<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5510 &lt;result&gt; = bitcast &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5511</pre>
5512
5513<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5514<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5515 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5516
5517<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5518<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5519 non-aggregate first class value, and a type to cast it to, which must also be
5520 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5521 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5522 identical. If the source type is a pointer, the destination type must also be
5523 a pointer. This instruction supports bitwise conversion of vectors to
5524 integers and to vectors of other types (as long as they have the same
5525 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5526
5527<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5528<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5529 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5530 this conversion. The conversion is done as if the <tt>value</tt> had been
5531 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5532 be converted to other pointer types with this instruction. To convert
5533 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5534 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5535
5536<h5>Example:</h5>
5537<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5538 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5539 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5540 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]5541</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5542
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5543</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5544
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5545</div>
5546
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5547<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5548<h3>
5549 <a name="otherops">Other Operations</a>
5550</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5551
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5552<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5553
5554<p>The instructions in this category are the "miscellaneous" instructions, which
5555 defy better classification.</p>
5556
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5557<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5558<h4>
5559 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5560</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5561
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5562<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5563
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5564<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5565<pre>
5566 &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5567</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5568
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5569<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5570<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5571 boolean values based on comparison of its two integer, integer vector, or
5572 pointer operands.</p>
5573
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5574<h5>Arguments:</h5>
5575<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5576 the condition code indicating the kind of comparison to perform. It is not a
5577 value, just a keyword. The possible condition code are:</p>
5578
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5579<ol>
5580 <li><tt>eq</tt>: equal</li>
5581 <li><tt>ne</tt>: not equal </li>
5582 <li><tt>ugt</tt>: unsigned greater than</li>
5583 <li><tt>uge</tt>: unsigned greater or equal</li>
5584 <li><tt>ult</tt>: unsigned less than</li>
5585 <li><tt>ule</tt>: unsigned less or equal</li>
5586 <li><tt>sgt</tt>: signed greater than</li>
5587 <li><tt>sge</tt>: signed greater or equal</li>
5588 <li><tt>slt</tt>: signed less than</li>
5589 <li><tt>sle</tt>: signed less or equal</li>
5590</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5591
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]5592<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5593 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5594 typed. They must also be identical types.</p>
5595
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5596<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5597<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5598 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5599 either an <a href="#t_integer"><tt>i1</tt></a> or vector of <tt>i1</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5600 result, as follows:</p>
5601
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5602<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5603 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5604 <tt>false</tt> otherwise. No sign interpretation is necessary or
5605 performed.</li>
5606
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5607 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5608 <tt>false</tt> otherwise. No sign interpretation is necessary or
5609 performed.</li>
5610
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5611 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5612 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5613
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5614 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5615 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5616 to <tt>op2</tt>.</li>
5617
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5618 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5619 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5620
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5621 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5622 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5623
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5624 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5625 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5626
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5627 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5628 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5629 to <tt>op2</tt>.</li>
5630
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5631 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5632 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5633
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5634 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5635 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5636</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5637
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5638<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5639 values are compared as if they were integers.</p>
5640
5641<p>If the operands are integer vectors, then they are compared element by
5642 element. The result is an <tt>i1</tt> vector with the same number of elements
5643 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5644
5645<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5646<pre>
5647 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5648 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5649 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5650 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5651 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5652 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5653</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5654
5655<p>Note that the code generator does not yet support vector types with
5656 the <tt>icmp</tt> instruction.</p>
5657
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5658</div>
5659
5660<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5661<h4>
5662 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5663</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5664
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5665<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5666
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5667<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5668<pre>
5669 &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5670</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5671
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5672<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5673<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5674 values based on comparison of its operands.</p>
5675
5676<p>If the operands are floating point scalars, then the result type is a boolean
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5677(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5678
5679<p>If the operands are floating point vectors, then the result type is a vector
5680 of boolean with the same number of elements as the operands being
5681 compared.</p>
5682
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5683<h5>Arguments:</h5>
5684<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5685 the condition code indicating the kind of comparison to perform. It is not a
5686 value, just a keyword. The possible condition code are:</p>
5687
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5688<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5689 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5690 <li><tt>oeq</tt>: ordered and equal</li>
5691 <li><tt>ogt</tt>: ordered and greater than </li>
5692 <li><tt>oge</tt>: ordered and greater than or equal</li>
5693 <li><tt>olt</tt>: ordered and less than </li>
5694 <li><tt>ole</tt>: ordered and less than or equal</li>
5695 <li><tt>one</tt>: ordered and not equal</li>
5696 <li><tt>ord</tt>: ordered (no nans)</li>
5697 <li><tt>ueq</tt>: unordered or equal</li>
5698 <li><tt>ugt</tt>: unordered or greater than </li>
5699 <li><tt>uge</tt>: unordered or greater than or equal</li>
5700 <li><tt>ult</tt>: unordered or less than </li>
5701 <li><tt>ule</tt>: unordered or less than or equal</li>
5702 <li><tt>une</tt>: unordered or not equal</li>
5703 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5704 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5705</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5706
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5707<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5708 <i>unordered</i> means that either operand may be a QNAN.</p>
5709
5710<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5711 a <a href="#t_floating">floating point</a> type or
5712 a <a href="#t_vector">vector</a> of floating point type. They must have
5713 identical types.</p>
5714
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5715<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]5716<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5717 according to the condition code given as <tt>cond</tt>. If the operands are
5718 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5719 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5720 follows:</p>
5721
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5722<ol>
5723 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5724
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5725 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5726 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5727
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5728 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5729 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5730
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5731 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5732 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5733
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5734 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5735 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5736
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5737 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5738 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5739
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5740 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5741 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5742
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5743 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5744
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5745 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5746 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5747
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5748 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5749 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5750
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5751 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5752 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5753
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5754 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5755 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5756
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5757 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5758 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5759
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5760 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5761 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5762
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5763 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5764
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5765 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5766</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5767
5768<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5769<pre>
5770 &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5771 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5772 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5773 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5774</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5775
5776<p>Note that the code generator does not yet support vector types with
5777 the <tt>fcmp</tt> instruction.</p>
5778
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5779</div>
5780
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5781<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5782<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5783 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5784</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5785
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5786<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5787
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5788<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5789<pre>
5790 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5791</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5792
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5793<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5794<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5795 SSA graph representing the function.</p>
5796
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5797<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5798<p>The type of the incoming values is specified with the first type field. After
5799 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5800 one pair for each predecessor basic block of the current block. Only values
5801 of <a href="#t_firstclass">first class</a> type may be used as the value
5802 arguments to the PHI node. Only labels may be used as the label
5803 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5804
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5805<p>There must be no non-phi instructions between the start of a basic block and
5806 the PHI instructions: i.e. PHI instructions must be first in a basic
5807 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5808
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5809<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5810 occur on the edge from the corresponding predecessor block to the current
5811 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5812 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]5813
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5814<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5815<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5816 specified by the pair corresponding to the predecessor basic block that
5817 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5818
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5819<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5820<pre>
5821Loop: ; Infinite loop that counts from 0 on up...
5822 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5823 %nextindvar = add i32 %indvar, 1
5824 br label %Loop
5825</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5826
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5827</div>
5828
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5829<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5830<h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5831 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5832</h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5833
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5834<div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5835
5836<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5837<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5838 &lt;result&gt; = select <i>selty</i> &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
5839
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5840 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5841</pre>
5842
5843<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5844<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5845 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5846
5847
5848<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5849<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5850 values indicating the condition, and two values of the
5851 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5852 vectors and the condition is a scalar, then entire vectors are selected, not
5853 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5854
5855<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5856<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5857 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5858
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5859<p>If the condition is a vector of i1, then the value arguments must be vectors
5860 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5861
5862<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5863<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5864 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5865</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5866
5867<p>Note that the code generator does not yet support conditions
5868 with vector type.</p>
5869
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5870</div>
5871
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5872<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5873<h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5874 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5875</h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5876
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5877<div>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5878
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5879<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5880<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]5881 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5882</pre>
5883
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5884<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5885<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5886
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5887<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5888<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5889
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5890<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5891 <li>The optional "tail" marker indicates that the callee function does not
5892 access any allocas or varargs in the caller. Note that calls may be
5893 marked "tail" even if they do not occur before
5894 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5895 present, the function call is eligible for tail call optimization,
5896 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Chengdc444e92010-03-08 21:05:02 +0000[diff] [blame]5897 optimized into a jump</a>. The code generator may optimize calls marked
5898 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5899 sibling call optimization</a> when the caller and callee have
5900 matching signatures, or 2) forced tail call optimization when the
5901 following extra requirements are met:
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5902 <ul>
5903 <li>Caller and callee both have the calling
5904 convention <tt>fastcc</tt>.</li>
5905 <li>The call is in tail position (ret immediately follows call and ret
5906 uses value of call or is void).</li>
5907 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohmanfbbee8d2010-03-02 01:08:11 +0000[diff] [blame]5908 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5909 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5910 constraints are met.</a></li>
5911 </ul>
5912 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5913
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5914 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5915 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5916 defaults to using C calling conventions. The calling convention of the
5917 call must match the calling convention of the target function, or else the
5918 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5919
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5920 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5921 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5922 '<tt>inreg</tt>' attributes are valid here.</li>
5923
5924 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5925 type of the return value. Functions that return no value are marked
5926 <tt><a href="#t_void">void</a></tt>.</li>
5927
5928 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5929 being invoked. The argument types must match the types implied by this
5930 signature. This type can be omitted if the function is not varargs and if
5931 the function type does not return a pointer to a function.</li>
5932
5933 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5934 be invoked. In most cases, this is a direct function invocation, but
5935 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5936 to function value.</li>
5937
5938 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]5939 signature argument types and parameter attributes. All arguments must be
5940 of <a href="#t_firstclass">first class</a> type. If the function
5941 signature indicates the function accepts a variable number of arguments,
5942 the extra arguments can be specified.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5943
5944 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5945 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5946 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5947</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5948
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5949<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5950<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5951 a specified function, with its incoming arguments bound to the specified
5952 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5953 function, control flow continues with the instruction after the function
5954 call, and the return value of the function is bound to the result
5955 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5956
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5957<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5958<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]5959 %retval = call i32 @test(i32 %argc)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]5960 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]5961 %X = tail call i32 @foo() <i>; yields i32</i>
5962 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5963 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]5964
5965 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5966 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]5967 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5968 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]5969 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]5970 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5971</pre>
5972
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5973<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]5974standard C99 library as being the C99 library functions, and may perform
5975optimizations or generate code for them under that assumption. This is
5976something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5977freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5978
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5979</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5980
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5981<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5982<h4>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]5983 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5984</h4>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5985
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5986<div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5987
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5988<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5989<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5990 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5991</pre>
5992
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5993<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5994<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5995 the "variable argument" area of a function call. It is used to implement the
5996 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5997
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5998<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5999<p>This instruction takes a <tt>va_list*</tt> value and the type of the
6000 argument. It returns a value of the specified argument type and increments
6001 the <tt>va_list</tt> to point to the next argument. The actual type
6002 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6003
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]6004<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6005<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
6006 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
6007 to the next argument. For more information, see the variable argument
6008 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6009
6010<p>It is legal for this instruction to be called in a function which does not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6011 take a variable number of arguments, for example, the <tt>vfprintf</tt>
6012 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6013
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6014<p><tt>va_arg</tt> is an LLVM instruction instead of
6015 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
6016 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6017
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]6018<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6019<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
6020
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6021<p>Note that the code generator does not yet fully support va_arg on many
6022 targets. Also, it does not currently support va_arg with aggregate types on
6023 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]6024
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6025</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6026
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6027<!-- _______________________________________________________________________ -->
6028<h4>
6029 <a name="i_landingpad">'<tt>landingpad</tt>' Instruction</a>
6030</h4>
6031
6032<div>
6033
6034<h5>Syntax:</h5>
6035<pre>
Bill Wendlingbf13ee12011-08-08 08:06:05 +0000[diff] [blame]6036 &lt;resultval&gt; = landingpad &lt;somety&gt; personality &lt;type&gt; &lt;pers_fn&gt; &lt;clause&gt;+
6037 &lt;resultval&gt; = landingpad &lt;somety&gt; personality &lt;type&gt; &lt;pers_fn&gt; cleanup &lt;clause&gt;*
6038
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6039 &lt;clause&gt; := catch &lt;type&gt; &lt;value&gt;
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame]6040 &lt;clause&gt; := filter &lt;array constant type&gt; &lt;array constant&gt;
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6041</pre>
6042
6043<h5>Overview:</h5>
6044<p>The '<tt>landingpad</tt>' instruction is used by
6045 <a href="ExceptionHandling.html#overview">LLVM's exception handling
6046 system</a> to specify that a basic block is a landing pad &mdash; one where
6047 the exception lands, and corresponds to the code found in the
6048 <i><tt>catch</tt></i> portion of a <i><tt>try/catch</tt></i> sequence. It
6049 defines values supplied by the personality function (<tt>pers_fn</tt>) upon
6050 re-entry to the function. The <tt>resultval</tt> has the
6051 type <tt>somety</tt>.</p>
6052
6053<h5>Arguments:</h5>
6054<p>This instruction takes a <tt>pers_fn</tt> value. This is the personality
6055 function associated with the unwinding mechanism. The optional
6056 <tt>cleanup</tt> flag indicates that the landing pad block is a cleanup.</p>
6057
6058<p>A <tt>clause</tt> begins with the clause type &mdash; <tt>catch</tt>
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame]6059 or <tt>filter</tt> &mdash; and contains the global variable representing the
6060 "type" that may be caught or filtered respectively. Unlike the
6061 <tt>catch</tt> clause, the <tt>filter</tt> clause takes an array constant as
6062 its argument. Use "<tt>[0 x i8**] undef</tt>" for a filter which cannot
6063 throw. The '<tt>landingpad</tt>' instruction must contain <em>at least</em>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6064 one <tt>clause</tt> or the <tt>cleanup</tt> flag.</p>
6065
6066<h5>Semantics:</h5>
6067<p>The '<tt>landingpad</tt>' instruction defines the values which are set by the
6068 personality function (<tt>pers_fn</tt>) upon re-entry to the function, and
6069 therefore the "result type" of the <tt>landingpad</tt> instruction. As with
6070 calling conventions, how the personality function results are represented in
6071 LLVM IR is target specific.</p>
6072
Bill Wendlingb7a01352011-08-03 17:17:06 +0000[diff] [blame]6073<p>The clauses are applied in order from top to bottom. If two
6074 <tt>landingpad</tt> instructions are merged together through inlining, the
Bill Wendling2905c322011-08-08 07:58:58 +0000[diff] [blame]6075 clauses from the calling function are appended to the list of clauses.</p>
Bill Wendlingb7a01352011-08-03 17:17:06 +0000[diff] [blame]6076
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6077<p>The <tt>landingpad</tt> instruction has several restrictions:</p>
6078
6079<ul>
6080 <li>A landing pad block is a basic block which is the unwind destination of an
6081 '<tt>invoke</tt>' instruction.</li>
6082 <li>A landing pad block must have a '<tt>landingpad</tt>' instruction as its
6083 first non-PHI instruction.</li>
6084 <li>There can be only one '<tt>landingpad</tt>' instruction within the landing
6085 pad block.</li>
6086 <li>A basic block that is not a landing pad block may not include a
6087 '<tt>landingpad</tt>' instruction.</li>
6088 <li>All '<tt>landingpad</tt>' instructions in a function must have the same
6089 personality function.</li>
6090</ul>
6091
6092<h5>Example:</h5>
6093<pre>
6094 ;; A landing pad which can catch an integer.
6095 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
6096 catch i8** @_ZTIi
6097 ;; A landing pad that is a cleanup.
6098 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame]6099 cleanup
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6100 ;; A landing pad which can catch an integer and can only throw a double.
6101 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
6102 catch i8** @_ZTIi
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame]6103 filter [1 x i8**] [@_ZTId]
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6104</pre>
6105
6106</div>
6107
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6108</div>
6109
6110</div>
6111
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6112<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6113<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]6114<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6115
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6116<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6117
6118<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6119 well known names and semantics and are required to follow certain
6120 restrictions. Overall, these intrinsics represent an extension mechanism for
6121 the LLVM language that does not require changing all of the transformations
6122 in LLVM when adding to the language (or the bitcode reader/writer, the
6123 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6124
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]6125<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6126 prefix is reserved in LLVM for intrinsic names; thus, function names may not
6127 begin with this prefix. Intrinsic functions must always be external
6128 functions: you cannot define the body of intrinsic functions. Intrinsic
6129 functions may only be used in call or invoke instructions: it is illegal to
6130 take the address of an intrinsic function. Additionally, because intrinsic
6131 functions are part of the LLVM language, it is required if any are added that
6132 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6133
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6134<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
6135 family of functions that perform the same operation but on different data
6136 types. Because LLVM can represent over 8 million different integer types,
6137 overloading is used commonly to allow an intrinsic function to operate on any
6138 integer type. One or more of the argument types or the result type can be
6139 overloaded to accept any integer type. Argument types may also be defined as
6140 exactly matching a previous argument's type or the result type. This allows
6141 an intrinsic function which accepts multiple arguments, but needs all of them
6142 to be of the same type, to only be overloaded with respect to a single
6143 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6144
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6145<p>Overloaded intrinsics will have the names of its overloaded argument types
6146 encoded into its function name, each preceded by a period. Only those types
6147 which are overloaded result in a name suffix. Arguments whose type is matched
6148 against another type do not. For example, the <tt>llvm.ctpop</tt> function
6149 can take an integer of any width and returns an integer of exactly the same
6150 integer width. This leads to a family of functions such as
6151 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
6152 %val)</tt>. Only one type, the return type, is overloaded, and only one type
6153 suffix is required. Because the argument's type is matched against the return
6154 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6155
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6156<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6157 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6158
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6159<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6160<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6161 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6162</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6163
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6164<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6165
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6166<p>Variable argument support is defined in LLVM with
6167 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
6168 intrinsic functions. These functions are related to the similarly named
6169 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6170
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6171<p>All of these functions operate on arguments that use a target-specific value
6172 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
6173 not define what this type is, so all transformations should be prepared to
6174 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6175
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]6176<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6177 instruction and the variable argument handling intrinsic functions are
6178 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6179
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]6180<pre class="doc_code">
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6181define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6182 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6183 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6184 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6185 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6186
6187 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6188 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6189
6190 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6191 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6192 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6193 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6194 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6195
6196 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6197 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]6198 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6199}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6200
6201declare void @llvm.va_start(i8*)
6202declare void @llvm.va_copy(i8*, i8*)
6203declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6204</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6205
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6206<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6207<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6208 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6209</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6210
6211
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6212<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6213
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6214<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6215<pre>
6216 declare void %llvm.va_start(i8* &lt;arglist&gt;)
6217</pre>
6218
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6219<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6220<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
6221 for subsequent use by <tt><a href="#i_va_arg">va_arg</a></tt>.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6222
6223<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6224<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6225
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6226<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6227<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6228 macro available in C. In a target-dependent way, it initializes
6229 the <tt>va_list</tt> element to which the argument points, so that the next
6230 call to <tt>va_arg</tt> will produce the first variable argument passed to
6231 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
6232 need to know the last argument of the function as the compiler can figure
6233 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6234
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6235</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6236
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6237<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6238<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6239 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6240</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6241
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6242<div>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6243
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6244<h5>Syntax:</h5>
6245<pre>
6246 declare void @llvm.va_end(i8* &lt;arglist&gt;)
6247</pre>
6248
6249<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6250<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6251 which has been initialized previously
6252 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
6253 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6254
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6255<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6256<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6257
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6258<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6259<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6260 macro available in C. In a target-dependent way, it destroys
6261 the <tt>va_list</tt> element to which the argument points. Calls
6262 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
6263 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
6264 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6265
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6266</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6267
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6268<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6269<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6270 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6271</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6272
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6273<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6274
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6275<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6276<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6277 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6278</pre>
6279
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6280<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6281<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6282 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6283
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6284<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6285<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6286 The second argument is a pointer to a <tt>va_list</tt> element to copy
6287 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6288
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6289<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6290<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6291 macro available in C. In a target-dependent way, it copies the
6292 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
6293 element. This intrinsic is necessary because
6294 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
6295 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6296
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6297</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6298
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6299</div>
6300
Bill Wendling0246bb72011-07-31 06:45:03 +0000[diff] [blame]6301</div>
6302
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6303<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6304<h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6305 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6306</h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6307
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6308<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6309
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6310<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]6311Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6312intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
6313roots on the stack</a>, as well as garbage collector implementations that
6314require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
6315barriers. Front-ends for type-safe garbage collected languages should generate
6316these intrinsics to make use of the LLVM garbage collectors. For more details,
6317see <a href="GarbageCollection.html">Accurate Garbage Collection with
6318LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]6319
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6320<p>The garbage collection intrinsics only operate on objects in the generic
6321 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]6322
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6323<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6324<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6325 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6326</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6327
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6328<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6329
6330<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6331<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6332 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6333</pre>
6334
6335<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]6336<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6337 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6338
6339<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6340<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6341 root pointer. The second pointer (which must be either a constant or a
6342 global value address) contains the meta-data to be associated with the
6343 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6344
6345<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]6346<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6347 location. At compile-time, the code generator generates information to allow
6348 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
6349 intrinsic may only be used in a function which <a href="#gc">specifies a GC
6350 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6351
6352</div>
6353
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6354<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6355<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6356 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6357</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6358
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6359<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6360
6361<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6362<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6363 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6364</pre>
6365
6366<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6367<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6368 locations, allowing garbage collector implementations that require read
6369 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6370
6371<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]6372<p>The second argument is the address to read from, which should be an address
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6373 allocated from the garbage collector. The first object is a pointer to the
6374 start of the referenced object, if needed by the language runtime (otherwise
6375 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6376
6377<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6378<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6379 instruction, but may be replaced with substantially more complex code by the
6380 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
6381 may only be used in a function which <a href="#gc">specifies a GC
6382 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6383
6384</div>
6385
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6386<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6387<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6388 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6389</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6390
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6391<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6392
6393<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6394<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6395 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6396</pre>
6397
6398<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6399<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6400 locations, allowing garbage collector implementations that require write
6401 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6402
6403<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]6404<p>The first argument is the reference to store, the second is the start of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6405 object to store it to, and the third is the address of the field of Obj to
6406 store to. If the runtime does not require a pointer to the object, Obj may
6407 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6408
6409<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6410<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6411 instruction, but may be replaced with substantially more complex code by the
6412 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
6413 may only be used in a function which <a href="#gc">specifies a GC
6414 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6415
6416</div>
6417
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6418</div>
6419
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6420<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6421<h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6422 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6423</h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6424
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6425<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6426
6427<p>These intrinsics are provided by LLVM to expose special features that may
6428 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6429
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6430<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6431<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6432 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6433</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6434
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6435<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6436
6437<h5>Syntax:</h5>
6438<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6439 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6440</pre>
6441
6442<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6443<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
6444 target-specific value indicating the return address of the current function
6445 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6446
6447<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6448<p>The argument to this intrinsic indicates which function to return the address
6449 for. Zero indicates the calling function, one indicates its caller, etc.
6450 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6451
6452<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6453<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
6454 indicating the return address of the specified call frame, or zero if it
6455 cannot be identified. The value returned by this intrinsic is likely to be
6456 incorrect or 0 for arguments other than zero, so it should only be used for
6457 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6458
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6459<p>Note that calling this intrinsic does not prevent function inlining or other
6460 aggressive transformations, so the value returned may not be that of the
6461 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6462
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6463</div>
6464
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6465<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6466<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6467 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6468</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6469
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6470<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6471
6472<h5>Syntax:</h5>
6473<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6474 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6475</pre>
6476
6477<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6478<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6479 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6480
6481<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6482<p>The argument to this intrinsic indicates which function to return the frame
6483 pointer for. Zero indicates the calling function, one indicates its caller,
6484 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6485
6486<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6487<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6488 indicating the frame address of the specified call frame, or zero if it
6489 cannot be identified. The value returned by this intrinsic is likely to be
6490 incorrect or 0 for arguments other than zero, so it should only be used for
6491 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6492
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6493<p>Note that calling this intrinsic does not prevent function inlining or other
6494 aggressive transformations, so the value returned may not be that of the
6495 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6496
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6497</div>
6498
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6499<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6500<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6501 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6502</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6503
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6504<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6505
6506<h5>Syntax:</h5>
6507<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6508 declare i8* @llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6509</pre>
6510
6511<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6512<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6513 of the function stack, for use
6514 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6515 useful for implementing language features like scoped automatic variable
6516 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6517
6518<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6519<p>This intrinsic returns a opaque pointer value that can be passed
6520 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6521 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6522 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6523 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6524 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6525 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6526
6527</div>
6528
6529<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6530<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6531 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6532</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6533
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6534<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6535
6536<h5>Syntax:</h5>
6537<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6538 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6539</pre>
6540
6541<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6542<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6543 the function stack to the state it was in when the
6544 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6545 executed. This is useful for implementing language features like scoped
6546 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6547
6548<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6549<p>See the description
6550 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6551
6552</div>
6553
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6554<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6555<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6556 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6557</h4>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6558
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6559<div>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6560
6561<h5>Syntax:</h5>
6562<pre>
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6563 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;, i32 &lt;cache type&gt;)
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6564</pre>
6565
6566<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6567<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6568 insert a prefetch instruction if supported; otherwise, it is a noop.
6569 Prefetches have no effect on the behavior of the program but can change its
6570 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6571
6572<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6573<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6574 specifier determining if the fetch should be for a read (0) or write (1),
6575 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6576 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6577 specifies whether the prefetch is performed on the data (1) or instruction (0)
6578 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6579 must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6580
6581<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6582<p>This intrinsic does not modify the behavior of the program. In particular,
6583 prefetches cannot trap and do not produce a value. On targets that support
6584 this intrinsic, the prefetch can provide hints to the processor cache for
6585 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6586
6587</div>
6588
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6589<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6590<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6591 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6592</h4>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6593
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6594<div>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6595
6596<h5>Syntax:</h5>
6597<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6598 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6599</pre>
6600
6601<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6602<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6603 Counter (PC) in a region of code to simulators and other tools. The method
6604 is target specific, but it is expected that the marker will use exported
6605 symbols to transmit the PC of the marker. The marker makes no guarantees
6606 that it will remain with any specific instruction after optimizations. It is
6607 possible that the presence of a marker will inhibit optimizations. The
6608 intended use is to be inserted after optimizations to allow correlations of
6609 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6610
6611<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6612<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6613
6614<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6615<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6616 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6617
6618</div>
6619
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6620<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6621<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6622 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6623</h4>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6624
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6625<div>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6626
6627<h5>Syntax:</h5>
6628<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]6629 declare i64 @llvm.readcyclecounter()
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6630</pre>
6631
6632<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6633<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6634 counter register (or similar low latency, high accuracy clocks) on those
6635 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6636 should map to RPCC. As the backing counters overflow quickly (on the order
6637 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6638
6639<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6640<p>When directly supported, reading the cycle counter should not modify any
6641 memory. Implementations are allowed to either return a application specific
6642 value or a system wide value. On backends without support, this is lowered
6643 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6644
6645</div>
6646
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6647</div>
6648
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6649<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6650<h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6651 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6652</h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6653
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6654<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6655
6656<p>LLVM provides intrinsics for a few important standard C library functions.
6657 These intrinsics allow source-language front-ends to pass information about
6658 the alignment of the pointer arguments to the code generator, providing
6659 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6660
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6661<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6662<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6663 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6664</h4>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6665
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6666<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6667
6668<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6669<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
Mon P Wange88909b2010-04-07 06:35:53 +0000[diff] [blame]6670 integer bit width and for different address spaces. Not all targets support
6671 all bit widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6672
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6673<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6674 declare void @llvm.memcpy.p0i8.p0i8.i32(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6675 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6676 declare void @llvm.memcpy.p0i8.p0i8.i64(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6677 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6678</pre>
6679
6680<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6681<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6682 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6683
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6684<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6685 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6686 and the pointers can be in specified address spaces.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6687
6688<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6689
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6690<p>The first argument is a pointer to the destination, the second is a pointer
6691 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6692 number of bytes to copy, the fourth argument is the alignment of the
6693 source and destination locations, and the fifth is a boolean indicating a
6694 volatile access.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6695
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6696<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6697 then the caller guarantees that both the source and destination pointers are
6698 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6699
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6700<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6701 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6702 The detailed access behavior is not very cleanly specified and it is unwise
6703 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6704
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6705<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6706
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6707<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6708 source location to the destination location, which are not allowed to
6709 overlap. It copies "len" bytes of memory over. If the argument is known to
6710 be aligned to some boundary, this can be specified as the fourth argument,
6711 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6712
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6713</div>
6714
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6715<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6716<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6717 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6718</h4>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6719
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6720<div>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6721
6722<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6723<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Mon P Wange88909b2010-04-07 06:35:53 +0000[diff] [blame]6724 width and for different address space. Not all targets support all bit
6725 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6726
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6727<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6728 declare void @llvm.memmove.p0i8.p0i8.i32(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6729 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6730 declare void @llvm.memmove.p0i8.p0i8.i64(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6731 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6732</pre>
6733
6734<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6735<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6736 source location to the destination location. It is similar to the
6737 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6738 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6739
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6740<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6741 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6742 and the pointers can be in specified address spaces.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6743
6744<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6745
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6746<p>The first argument is a pointer to the destination, the second is a pointer
6747 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6748 number of bytes to copy, the fourth argument is the alignment of the
6749 source and destination locations, and the fifth is a boolean indicating a
6750 volatile access.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6751
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6752<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6753 then the caller guarantees that the source and destination pointers are
6754 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6755
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6756<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6757 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6758 The detailed access behavior is not very cleanly specified and it is unwise
6759 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6760
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6761<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6762
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6763<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6764 source location to the destination location, which may overlap. It copies
6765 "len" bytes of memory over. If the argument is known to be aligned to some
6766 boundary, this can be specified as the fourth argument, otherwise it should
6767 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6768
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6769</div>
6770
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6771<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6772<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6773 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6774</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6775
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6776<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6777
6778<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6779<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6780 width and for different address spaces. However, not all targets support all
6781 bit widths.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6782
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6783<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6784 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6785 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6786 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6787 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6788</pre>
6789
6790<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6791<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6792 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6793
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6794<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6795 intrinsic does not return a value and takes extra alignment/volatile
6796 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6797
6798<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6799<p>The first argument is a pointer to the destination to fill, the second is the
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6800 byte value with which to fill it, the third argument is an integer argument
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6801 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6802 alignment of the destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6803
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6804<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6805 then the caller guarantees that the destination pointer is aligned to that
6806 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6807
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6808<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6809 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6810 The detailed access behavior is not very cleanly specified and it is unwise
6811 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6812
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6813<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6814<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6815 at the destination location. If the argument is known to be aligned to some
6816 boundary, this can be specified as the fourth argument, otherwise it should
6817 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6818
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6819</div>
6820
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6821<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6822<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6823 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6824</h4>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6825
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6826<div>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6827
6828<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6829<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6830 floating point or vector of floating point type. Not all targets support all
6831 types however.</p>
6832
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6833<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6834 declare float @llvm.sqrt.f32(float %Val)
6835 declare double @llvm.sqrt.f64(double %Val)
6836 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6837 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6838 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6839</pre>
6840
6841<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6842<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6843 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6844 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6845 behavior for negative numbers other than -0.0 (which allows for better
6846 optimization, because there is no need to worry about errno being
6847 set). <tt>llvm.sqrt(-0.0)</tt> is defined to return -0.0 like IEEE sqrt.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6848
6849<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6850<p>The argument and return value are floating point numbers of the same
6851 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6852
6853<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6854<p>This function returns the sqrt of the specified operand if it is a
6855 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6856
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6857</div>
6858
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6859<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6860<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6861 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6862</h4>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6863
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6864<div>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6865
6866<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6867<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6868 floating point or vector of floating point type. Not all targets support all
6869 types however.</p>
6870
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6871<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6872 declare float @llvm.powi.f32(float %Val, i32 %power)
6873 declare double @llvm.powi.f64(double %Val, i32 %power)
6874 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6875 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6876 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6877</pre>
6878
6879<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6880<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6881 specified (positive or negative) power. The order of evaluation of
6882 multiplications is not defined. When a vector of floating point type is
6883 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6884
6885<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6886<p>The second argument is an integer power, and the first is a value to raise to
6887 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6888
6889<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6890<p>This function returns the first value raised to the second power with an
6891 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6892
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6893</div>
6894
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6895<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6896<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6897 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6898</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6899
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6900<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6901
6902<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6903<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6904 floating point or vector of floating point type. Not all targets support all
6905 types however.</p>
6906
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6907<pre>
6908 declare float @llvm.sin.f32(float %Val)
6909 declare double @llvm.sin.f64(double %Val)
6910 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6911 declare fp128 @llvm.sin.f128(fp128 %Val)
6912 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6913</pre>
6914
6915<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6916<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6917
6918<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6919<p>The argument and return value are floating point numbers of the same
6920 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6921
6922<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6923<p>This function returns the sine of the specified operand, returning the same
6924 values as the libm <tt>sin</tt> functions would, and handles error conditions
6925 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6926
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6927</div>
6928
6929<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6930<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6931 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6932</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6933
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6934<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6935
6936<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6937<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6938 floating point or vector of floating point type. Not all targets support all
6939 types however.</p>
6940
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6941<pre>
6942 declare float @llvm.cos.f32(float %Val)
6943 declare double @llvm.cos.f64(double %Val)
6944 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6945 declare fp128 @llvm.cos.f128(fp128 %Val)
6946 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6947</pre>
6948
6949<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6950<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6951
6952<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6953<p>The argument and return value are floating point numbers of the same
6954 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6955
6956<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6957<p>This function returns the cosine of the specified operand, returning the same
6958 values as the libm <tt>cos</tt> functions would, and handles error conditions
6959 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6960
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6961</div>
6962
6963<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6964<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6965 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6966</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6967
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6968<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6969
6970<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6971<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6972 floating point or vector of floating point type. Not all targets support all
6973 types however.</p>
6974
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6975<pre>
6976 declare float @llvm.pow.f32(float %Val, float %Power)
6977 declare double @llvm.pow.f64(double %Val, double %Power)
6978 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6979 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6980 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6981</pre>
6982
6983<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6984<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6985 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6986
6987<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6988<p>The second argument is a floating point power, and the first is a value to
6989 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6990
6991<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6992<p>This function returns the first value raised to the second power, returning
6993 the same values as the libm <tt>pow</tt> functions would, and handles error
6994 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6995
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6996</div>
6997
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6998</div>
6999
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]7000<!-- _______________________________________________________________________ -->
7001<h4>
7002 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
7003</h4>
7004
7005<div>
7006
7007<h5>Syntax:</h5>
7008<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
7009 floating point or vector of floating point type. Not all targets support all
7010 types however.</p>
7011
7012<pre>
7013 declare float @llvm.exp.f32(float %Val)
7014 declare double @llvm.exp.f64(double %Val)
7015 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
7016 declare fp128 @llvm.exp.f128(fp128 %Val)
7017 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
7018</pre>
7019
7020<h5>Overview:</h5>
7021<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
7022
7023<h5>Arguments:</h5>
7024<p>The argument and return value are floating point numbers of the same
7025 type.</p>
7026
7027<h5>Semantics:</h5>
7028<p>This function returns the same values as the libm <tt>exp</tt> functions
7029 would, and handles error conditions in the same way.</p>
7030
7031</div>
7032
7033<!-- _______________________________________________________________________ -->
7034<h4>
7035 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
7036</h4>
7037
7038<div>
7039
7040<h5>Syntax:</h5>
7041<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
7042 floating point or vector of floating point type. Not all targets support all
7043 types however.</p>
7044
7045<pre>
7046 declare float @llvm.log.f32(float %Val)
7047 declare double @llvm.log.f64(double %Val)
7048 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
7049 declare fp128 @llvm.log.f128(fp128 %Val)
7050 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
7051</pre>
7052
7053<h5>Overview:</h5>
7054<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
7055
7056<h5>Arguments:</h5>
7057<p>The argument and return value are floating point numbers of the same
7058 type.</p>
7059
7060<h5>Semantics:</h5>
7061<p>This function returns the same values as the libm <tt>log</tt> functions
7062 would, and handles error conditions in the same way.</p>
7063
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]7064<h4>
7065 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
7066</h4>
7067
7068<div>
7069
7070<h5>Syntax:</h5>
7071<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
7072 floating point or vector of floating point type. Not all targets support all
7073 types however.</p>
7074
7075<pre>
7076 declare float @llvm.fma.f32(float %a, float %b, float %c)
7077 declare double @llvm.fma.f64(double %a, double %b, double %c)
7078 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
7079 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
7080 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
7081</pre>
7082
7083<h5>Overview:</h5>
Cameron Zwarichabc43e62011-07-08 22:13:55 +0000[diff] [blame]7084<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]7085 operation.</p>
7086
7087<h5>Arguments:</h5>
7088<p>The argument and return value are floating point numbers of the same
7089 type.</p>
7090
7091<h5>Semantics:</h5>
7092<p>This function returns the same values as the libm <tt>fma</tt> functions
7093 would.</p>
7094
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]7095</div>
7096
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7097<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7098<h3>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7099 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7100</h3>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7101
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7102<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7103
7104<p>LLVM provides intrinsics for a few important bit manipulation operations.
7105 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7106
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7107<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7108<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]7109 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7110</h4>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7111
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7112<div>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7113
7114<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]7115<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7116 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
7117
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7118<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7119 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
7120 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
7121 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7122</pre>
7123
7124<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7125<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
7126 values with an even number of bytes (positive multiple of 16 bits). These
7127 are useful for performing operations on data that is not in the target's
7128 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7129
7130<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7131<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
7132 and low byte of the input i16 swapped. Similarly,
7133 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
7134 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
7135 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
7136 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
7137 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
7138 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7139
7140</div>
7141
7142<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7143<h4>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]7144 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7145</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7146
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7147<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7148
7149<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]7150<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7151 width, or on any vector with integer elements. Not all targets support all
7152 bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7153
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7154<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7155 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7156 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7157 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7158 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
7159 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7160 declare &lt;2 x i32&gt; @llvm.ctpop.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7161</pre>
7162
7163<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7164<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
7165 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7166
7167<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7168<p>The only argument is the value to be counted. The argument may be of any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7169 integer type, or a vector with integer elements.
7170 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7171
7172<h5>Semantics:</h5>
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7173<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
7174 element of a vector.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7175
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7176</div>
7177
7178<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7179<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]7180 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7181</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7182
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7183<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7184
7185<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7186<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7187 integer bit width, or any vector whose elements are integers. Not all
7188 targets support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7189
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7190<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7191 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
7192 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7193 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7194 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
7195 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7196 declare &lt;2 x i32&gt; @llvm.ctlz.v2i32(&lt;2 x i32&gt; &lt;src;gt)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7197</pre>
7198
7199<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7200<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
7201 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7202
7203<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7204<p>The only argument is the value to be counted. The argument may be of any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7205 integer type, or any vector type with integer element type.
7206 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7207
7208<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7209<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7210 zeros in a variable, or within each element of the vector if the operation
7211 is of vector type. If the src == 0 then the result is the size in bits of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7212 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7213
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7214</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]7215
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7216<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7217<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]7218 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7219</h4>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7220
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7221<div>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7222
7223<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7224<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7225 integer bit width, or any vector of integer elements. Not all targets
7226 support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7227
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7228<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7229 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
7230 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7231 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7232 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
7233 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7234 declase &lt;2 x i32&gt; @llvm.cttz.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7235</pre>
7236
7237<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7238<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
7239 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7240
7241<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7242<p>The only argument is the value to be counted. The argument may be of any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7243 integer type, or a vectory with integer element type.. The return type
7244 must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7245
7246<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7247<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7248 zeros in a variable, or within each element of a vector.
7249 If the src == 0 then the result is the size in bits of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7250 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7251
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7252</div>
7253
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7254</div>
7255
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7256<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7257<h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7258 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7259</h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7260
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7261<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7262
7263<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7264
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7265<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7266<h4>
7267 <a name="int_sadd_overflow">
7268 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
7269 </a>
7270</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7271
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7272<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7273
7274<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7275<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7276 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7277
7278<pre>
7279 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
7280 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7281 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
7282</pre>
7283
7284<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7285<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7286 a signed addition of the two arguments, and indicate whether an overflow
7287 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7288
7289<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7290<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7291 be of integer types of any bit width, but they must have the same bit
7292 width. The second element of the result structure must be of
7293 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7294 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7295
7296<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7297<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7298 a signed addition of the two variables. They return a structure &mdash; the
7299 first element of which is the signed summation, and the second element of
7300 which is a bit specifying if the signed summation resulted in an
7301 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7302
7303<h5>Examples:</h5>
7304<pre>
7305 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7306 %sum = extractvalue {i32, i1} %res, 0
7307 %obit = extractvalue {i32, i1} %res, 1
7308 br i1 %obit, label %overflow, label %normal
7309</pre>
7310
7311</div>
7312
7313<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7314<h4>
7315 <a name="int_uadd_overflow">
7316 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
7317 </a>
7318</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7319
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7320<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7321
7322<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7323<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7324 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7325
7326<pre>
7327 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
7328 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7329 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
7330</pre>
7331
7332<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7333<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7334 an unsigned addition of the two arguments, and indicate whether a carry
7335 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7336
7337<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7338<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7339 be of integer types of any bit width, but they must have the same bit
7340 width. The second element of the result structure must be of
7341 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7342 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7343
7344<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7345<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7346 an unsigned addition of the two arguments. They return a structure &mdash;
7347 the first element of which is the sum, and the second element of which is a
7348 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7349
7350<h5>Examples:</h5>
7351<pre>
7352 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7353 %sum = extractvalue {i32, i1} %res, 0
7354 %obit = extractvalue {i32, i1} %res, 1
7355 br i1 %obit, label %carry, label %normal
7356</pre>
7357
7358</div>
7359
7360<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7361<h4>
7362 <a name="int_ssub_overflow">
7363 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
7364 </a>
7365</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7366
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7367<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7368
7369<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7370<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7371 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7372
7373<pre>
7374 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
7375 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7376 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
7377</pre>
7378
7379<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7380<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7381 a signed subtraction of the two arguments, and indicate whether an overflow
7382 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7383
7384<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7385<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7386 be of integer types of any bit width, but they must have the same bit
7387 width. The second element of the result structure must be of
7388 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7389 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7390
7391<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7392<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7393 a signed subtraction of the two arguments. They return a structure &mdash;
7394 the first element of which is the subtraction, and the second element of
7395 which is a bit specifying if the signed subtraction resulted in an
7396 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7397
7398<h5>Examples:</h5>
7399<pre>
7400 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7401 %sum = extractvalue {i32, i1} %res, 0
7402 %obit = extractvalue {i32, i1} %res, 1
7403 br i1 %obit, label %overflow, label %normal
7404</pre>
7405
7406</div>
7407
7408<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7409<h4>
7410 <a name="int_usub_overflow">
7411 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
7412 </a>
7413</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7414
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7415<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7416
7417<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7418<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7419 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7420
7421<pre>
7422 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
7423 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7424 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
7425</pre>
7426
7427<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7428<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7429 an unsigned subtraction of the two arguments, and indicate whether an
7430 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7431
7432<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7433<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7434 be of integer types of any bit width, but they must have the same bit
7435 width. The second element of the result structure must be of
7436 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7437 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7438
7439<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7440<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7441 an unsigned subtraction of the two arguments. They return a structure &mdash;
7442 the first element of which is the subtraction, and the second element of
7443 which is a bit specifying if the unsigned subtraction resulted in an
7444 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7445
7446<h5>Examples:</h5>
7447<pre>
7448 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7449 %sum = extractvalue {i32, i1} %res, 0
7450 %obit = extractvalue {i32, i1} %res, 1
7451 br i1 %obit, label %overflow, label %normal
7452</pre>
7453
7454</div>
7455
7456<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7457<h4>
7458 <a name="int_smul_overflow">
7459 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
7460 </a>
7461</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7462
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7463<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7464
7465<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7466<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7467 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7468
7469<pre>
7470 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
7471 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7472 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
7473</pre>
7474
7475<h5>Overview:</h5>
7476
7477<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7478 a signed multiplication of the two arguments, and indicate whether an
7479 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7480
7481<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7482<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7483 be of integer types of any bit width, but they must have the same bit
7484 width. The second element of the result structure must be of
7485 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7486 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7487
7488<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7489<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7490 a signed multiplication of the two arguments. They return a structure &mdash;
7491 the first element of which is the multiplication, and the second element of
7492 which is a bit specifying if the signed multiplication resulted in an
7493 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7494
7495<h5>Examples:</h5>
7496<pre>
7497 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7498 %sum = extractvalue {i32, i1} %res, 0
7499 %obit = extractvalue {i32, i1} %res, 1
7500 br i1 %obit, label %overflow, label %normal
7501</pre>
7502
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]7503</div>
7504
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7505<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7506<h4>
7507 <a name="int_umul_overflow">
7508 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7509 </a>
7510</h4>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7511
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7512<div>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7513
7514<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7515<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7516 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7517
7518<pre>
7519 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7520 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7521 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7522</pre>
7523
7524<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7525<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7526 a unsigned multiplication of the two arguments, and indicate whether an
7527 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7528
7529<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7530<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7531 be of integer types of any bit width, but they must have the same bit
7532 width. The second element of the result structure must be of
7533 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7534 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7535
7536<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7537<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7538 an unsigned multiplication of the two arguments. They return a structure
7539 &mdash; the first element of which is the multiplication, and the second
7540 element of which is a bit specifying if the unsigned multiplication resulted
7541 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7542
7543<h5>Examples:</h5>
7544<pre>
7545 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7546 %sum = extractvalue {i32, i1} %res, 0
7547 %obit = extractvalue {i32, i1} %res, 1
7548 br i1 %obit, label %overflow, label %normal
7549</pre>
7550
7551</div>
7552
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7553</div>
7554
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7555<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7556<h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7557 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7558</h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7559
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7560<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7561
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7562<p>Half precision floating point is a storage-only format. This means that it is
7563 a dense encoding (in memory) but does not support computation in the
7564 format.</p>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7565
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7566<p>This means that code must first load the half-precision floating point
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7567 value as an i16, then convert it to float with <a
7568 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7569 Computation can then be performed on the float value (including extending to
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7570 double etc). To store the value back to memory, it is first converted to
7571 float if needed, then converted to i16 with
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7572 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7573 storing as an i16 value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7574
7575<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7576<h4>
7577 <a name="int_convert_to_fp16">
7578 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7579 </a>
7580</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7581
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7582<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7583
7584<h5>Syntax:</h5>
7585<pre>
7586 declare i16 @llvm.convert.to.fp16(f32 %a)
7587</pre>
7588
7589<h5>Overview:</h5>
7590<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7591 a conversion from single precision floating point format to half precision
7592 floating point format.</p>
7593
7594<h5>Arguments:</h5>
7595<p>The intrinsic function contains single argument - the value to be
7596 converted.</p>
7597
7598<h5>Semantics:</h5>
7599<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7600 a conversion from single precision floating point format to half precision
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7601 floating point format. The return value is an <tt>i16</tt> which
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7602 contains the converted number.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7603
7604<h5>Examples:</h5>
7605<pre>
7606 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7607 store i16 %res, i16* @x, align 2
7608</pre>
7609
7610</div>
7611
7612<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7613<h4>
7614 <a name="int_convert_from_fp16">
7615 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7616 </a>
7617</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7618
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7619<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7620
7621<h5>Syntax:</h5>
7622<pre>
7623 declare f32 @llvm.convert.from.fp16(i16 %a)
7624</pre>
7625
7626<h5>Overview:</h5>
7627<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7628 a conversion from half precision floating point format to single precision
7629 floating point format.</p>
7630
7631<h5>Arguments:</h5>
7632<p>The intrinsic function contains single argument - the value to be
7633 converted.</p>
7634
7635<h5>Semantics:</h5>
7636<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7637 conversion from half single precision floating point format to single
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7638 precision floating point format. The input half-float value is represented by
7639 an <tt>i16</tt> value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7640
7641<h5>Examples:</h5>
7642<pre>
7643 %a = load i16* @x, align 2
7644 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7645</pre>
7646
7647</div>
7648
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7649</div>
7650
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7651<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7652<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7653 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7654</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7655
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7656<div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7657
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7658<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7659 prefix), are described in
7660 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7661 Level Debugging</a> document.</p>
7662
7663</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7664
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7665<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7666<h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7667 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7668</h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7669
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7670<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7671
7672<p>The LLVM exception handling intrinsics (which all start with
7673 <tt>llvm.eh.</tt> prefix), are described in
7674 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7675 Handling</a> document.</p>
7676
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7677</div>
7678
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7679<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7680<h3>
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]7681 <a name="int_trampoline">Trampoline Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7682</h3>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7683
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7684<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7685
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]7686<p>These intrinsics make it possible to excise one parameter, marked with
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]7687 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7688 The result is a callable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7689 function pointer lacking the nest parameter - the caller does not need to
7690 provide a value for it. Instead, the value to use is stored in advance in a
7691 "trampoline", a block of memory usually allocated on the stack, which also
7692 contains code to splice the nest value into the argument list. This is used
7693 to implement the GCC nested function address extension.</p>
7694
7695<p>For example, if the function is
7696 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7697 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7698 follows:</p>
7699
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]7700<pre class="doc_code">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7701 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7702 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]7703 call i8* @llvm.init.trampoline(i8* %tramp1, i8* bitcast (i32 (i8*, i32, i32)* @f to i8*), i8* %nval)
7704 %p = call i8* @llvm.adjust.trampoline(i8* %tramp1)
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7705 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7706</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7707
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7708<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7709 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7710
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7711<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7712<h4>
7713 <a name="int_it">
7714 '<tt>llvm.init.trampoline</tt>' Intrinsic
7715 </a>
7716</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7717
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7718<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7719
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7720<h5>Syntax:</h5>
7721<pre>
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]7722 declare void @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7723</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7724
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7725<h5>Overview:</h5>
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]7726<p>This fills the memory pointed to by <tt>tramp</tt> with executable code,
7727 turning it into a trampoline.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7728
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7729<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7730<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7731 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7732 sufficiently aligned block of memory; this memory is written to by the
7733 intrinsic. Note that the size and the alignment are target-specific - LLVM
7734 currently provides no portable way of determining them, so a front-end that
7735 generates this intrinsic needs to have some target-specific knowledge.
7736 The <tt>func</tt> argument must hold a function bitcast to
7737 an <tt>i8*</tt>.</p>
7738
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7739<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7740<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands4a544a72011-09-06 13:37:06 +0000[diff] [blame]7741 dependent code, turning it into a function. Then <tt>tramp</tt> needs to be
7742 passed to <a href="#int_at">llvm.adjust.trampoline</a> to get a pointer
7743 which can be <a href="#int_trampoline">bitcast (to a new function) and
7744 called</a>. The new function's signature is the same as that of
7745 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
7746 removed. At most one such <tt>nest</tt> argument is allowed, and it must be of
7747 pointer type. Calling the new function is equivalent to calling <tt>func</tt>
7748 with the same argument list, but with <tt>nval</tt> used for the missing
7749 <tt>nest</tt> argument. If, after calling <tt>llvm.init.trampoline</tt>, the
7750 memory pointed to by <tt>tramp</tt> is modified, then the effect of any later call
7751 to the returned function pointer is undefined.</p>
7752</div>
7753
7754<!-- _______________________________________________________________________ -->
7755<h4>
7756 <a name="int_at">
7757 '<tt>llvm.adjust.trampoline</tt>' Intrinsic
7758 </a>
7759</h4>
7760
7761<div>
7762
7763<h5>Syntax:</h5>
7764<pre>
7765 declare i8* @llvm.adjust.trampoline(i8* &lt;tramp&gt;)
7766</pre>
7767
7768<h5>Overview:</h5>
7769<p>This performs any required machine-specific adjustment to the address of a
7770 trampoline (passed as <tt>tramp</tt>).</p>
7771
7772<h5>Arguments:</h5>
7773<p><tt>tramp</tt> must point to a block of memory which already has trampoline code
7774 filled in by a previous call to <a href="#int_it"><tt>llvm.init.trampoline</tt>
7775 </a>.</p>
7776
7777<h5>Semantics:</h5>
7778<p>On some architectures the address of the code to be executed needs to be
7779 different to the address where the trampoline is actually stored. This
7780 intrinsic returns the executable address corresponding to <tt>tramp</tt>
7781 after performing the required machine specific adjustments.
7782 The pointer returned can then be <a href="#int_trampoline"> bitcast and
7783 executed</a>.
7784</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7785
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7786</div>
7787
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7788</div>
7789
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7790<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7791<h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7792 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7793</h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7794
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7795<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7796
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7797<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7798 hardware constructs for atomic operations and memory synchronization. This
7799 provides an interface to the hardware, not an interface to the programmer. It
7800 is aimed at a low enough level to allow any programming models or APIs
7801 (Application Programming Interfaces) which need atomic behaviors to map
7802 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7803 hardware provides a "universal IR" for source languages, it also provides a
7804 starting point for developing a "universal" atomic operation and
7805 synchronization IR.</p>
7806
7807<p>These do <em>not</em> form an API such as high-level threading libraries,
7808 software transaction memory systems, atomic primitives, and intrinsic
7809 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7810 application libraries. The hardware interface provided by LLVM should allow
7811 a clean implementation of all of these APIs and parallel programming models.
7812 No one model or paradigm should be selected above others unless the hardware
7813 itself ubiquitously does so.</p>
7814
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7815<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7816<h4>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7817 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7818</h4>
7819
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7820<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7821<h5>Syntax:</h5>
7822<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7823 declare void @llvm.memory.barrier(i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;, i1 &lt;device&gt;)
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7824</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7825
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7826<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7827<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7828 specific pairs of memory access types.</p>
7829
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7830<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7831<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7832 The first four arguments enables a specific barrier as listed below. The
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]7833 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7834 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7835
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7836<ul>
7837 <li><tt>ll</tt>: load-load barrier</li>
7838 <li><tt>ls</tt>: load-store barrier</li>
7839 <li><tt>sl</tt>: store-load barrier</li>
7840 <li><tt>ss</tt>: store-store barrier</li>
7841 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7842</ul>
7843
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7844<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7845<p>This intrinsic causes the system to enforce some ordering constraints upon
7846 the loads and stores of the program. This barrier does not
7847 indicate <em>when</em> any events will occur, it only enforces
7848 an <em>order</em> in which they occur. For any of the specified pairs of load
7849 and store operations (f.ex. load-load, or store-load), all of the first
7850 operations preceding the barrier will complete before any of the second
7851 operations succeeding the barrier begin. Specifically the semantics for each
7852 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7853
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7854<ul>
7855 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7856 after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7857 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7858 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7859 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7860 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7861 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7862 load after the barrier begins.</li>
7863</ul>
7864
7865<p>These semantics are applied with a logical "and" behavior when more than one
7866 is enabled in a single memory barrier intrinsic.</p>
7867
7868<p>Backends may implement stronger barriers than those requested when they do
7869 not support as fine grained a barrier as requested. Some architectures do
7870 not need all types of barriers and on such architectures, these become
7871 noops.</p>
7872
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7873<h5>Example:</h5>
7874<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7875%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7876%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7877 store i32 4, %ptr
7878
7879%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0b0669a2011-06-29 17:14:00 +0000[diff] [blame]7880 call void @llvm.memory.barrier(i1 false, i1 true, i1 false, i1 false, i1 true)
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7881 <i>; guarantee the above finishes</i>
7882 store i32 8, %ptr <i>; before this begins</i>
7883</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7884
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7885</div>
7886
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7887<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7888<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7889 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7890</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7891
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7892<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7893
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7894<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7895<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7896 any integer bit width and for different address spaces. Not all targets
7897 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7898
7899<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7900 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7901 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7902 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7903 declare i64 @llvm.atomic.cmp.swap.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt;)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7904</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7905
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7906<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7907<p>This loads a value in memory and compares it to a given value. If they are
7908 equal, it stores a new value into the memory.</p>
7909
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7910<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7911<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7912 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7913 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7914 this integer type. While any bit width integer may be used, targets may only
7915 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7916
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7917<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7918<p>This entire intrinsic must be executed atomically. It first loads the value
7919 in memory pointed to by <tt>ptr</tt> and compares it with the
7920 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7921 memory. The loaded value is yielded in all cases. This provides the
7922 equivalent of an atomic compare-and-swap operation within the SSA
7923 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7924
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7925<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7926<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7927%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7928%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7929 store i32 4, %ptr
7930
7931%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7932%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7933 <i>; yields {i32}:result1 = 4</i>
7934%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7935%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7936
7937%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7938%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7939 <i>; yields {i32}:result2 = 8</i>
7940%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7941
7942%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7943</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7944
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7945</div>
7946
7947<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7948<h4>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7949 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7950</h4>
7951
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7952<div>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7953<h5>Syntax:</h5>
7954
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7955<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7956 integer bit width. Not all targets support all bit widths however.</p>
7957
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7958<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7959 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7960 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7961 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7962 declare i64 @llvm.atomic.swap.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;val&gt;)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7963</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7964
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7965<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7966<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7967 the value from memory. It then stores the value in <tt>val</tt> in the memory
7968 at <tt>ptr</tt>.</p>
7969
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7970<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7971<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7972 the <tt>val</tt> argument and the result must be integers of the same bit
7973 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7974 integer type. The targets may only lower integer representations they
7975 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7976
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7977<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7978<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7979 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7980 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7981
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7982<h5>Examples:</h5>
7983<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7984%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7985%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7986 store i32 4, %ptr
7987
7988%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7989%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7990 <i>; yields {i32}:result1 = 4</i>
7991%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7992%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7993
7994%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7995%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7996 <i>; yields {i32}:result2 = 8</i>
7997
7998%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7999%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
8000</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8001
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]8002</div>
8003
8004<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8005<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8006 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8007</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8008
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8009<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8010
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]8011<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8012<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
8013 any integer bit width. Not all targets support all bit widths however.</p>
8014
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]8015<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8016 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8017 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8018 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8019 declare i64 @llvm.atomic.load.add.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]8020</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]8021
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8022<h5>Overview:</h5>
8023<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
8024 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
8025
8026<h5>Arguments:</h5>
8027<p>The intrinsic takes two arguments, the first a pointer to an integer value
8028 and the second an integer value. The result is also an integer value. These
8029 integer types can have any bit width, but they must all have the same bit
8030 width. The targets may only lower integer representations they support.</p>
8031
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]8032<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8033<p>This intrinsic does a series of operations atomically. It first loads the
8034 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
8035 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]8036
8037<h5>Examples:</h5>
8038<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]8039%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8040%ptr = bitcast i8* %mallocP to i32*
8041 store i32 4, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8042%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]8043 <i>; yields {i32}:result1 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8044%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]8045 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8046%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]8047 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8048%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]8049</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8050
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]8051</div>
8052
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8053<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8054<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8055 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8056</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8057
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8058<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8059
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8060<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8061<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
8062 any integer bit width and for different address spaces. Not all targets
8063 support all bit widths however.</p>
8064
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8065<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8066 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8067 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8068 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8069 declare i64 @llvm.atomic.load.sub.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8070</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8071
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8072<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]8073<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8074 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
8075
8076<h5>Arguments:</h5>
8077<p>The intrinsic takes two arguments, the first a pointer to an integer value
8078 and the second an integer value. The result is also an integer value. These
8079 integer types can have any bit width, but they must all have the same bit
8080 width. The targets may only lower integer representations they support.</p>
8081
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8082<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8083<p>This intrinsic does a series of operations atomically. It first loads the
8084 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
8085 result to <tt>ptr</tt>. It yields the original value stored
8086 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8087
8088<h5>Examples:</h5>
8089<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]8090%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8091%ptr = bitcast i8* %mallocP to i32*
8092 store i32 8, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8093%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8094 <i>; yields {i32}:result1 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8095%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8096 <i>; yields {i32}:result2 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8097%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8098 <i>; yields {i32}:result3 = 2</i>
8099%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
8100</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8101
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8102</div>
8103
8104<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8105<h4>
8106 <a name="int_atomic_load_and">
8107 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
8108 </a>
8109 <br>
8110 <a name="int_atomic_load_nand">
8111 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
8112 </a>
8113 <br>
8114 <a name="int_atomic_load_or">
8115 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
8116 </a>
8117 <br>
8118 <a name="int_atomic_load_xor">
8119 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
8120 </a>
8121</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8122
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8123<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8124
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8125<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8126<p>These are overloaded intrinsics. You can
8127 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
8128 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
8129 bit width and for different address spaces. Not all targets support all bit
8130 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8131
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8132<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8133 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8134 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8135 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8136 declare i64 @llvm.atomic.load.and.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8137</pre>
8138
8139<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8140 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8141 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8142 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8143 declare i64 @llvm.atomic.load.or.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8144</pre>
8145
8146<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8147 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8148 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8149 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8150 declare i64 @llvm.atomic.load.nand.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8151</pre>
8152
8153<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8154 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8155 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8156 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8157 declare i64 @llvm.atomic.load.xor.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8158</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8159
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8160<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8161<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
8162 the value stored in memory at <tt>ptr</tt>. It yields the original value
8163 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8164
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8165<h5>Arguments:</h5>
8166<p>These intrinsics take two arguments, the first a pointer to an integer value
8167 and the second an integer value. The result is also an integer value. These
8168 integer types can have any bit width, but they must all have the same bit
8169 width. The targets may only lower integer representations they support.</p>
8170
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8171<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8172<p>These intrinsics does a series of operations atomically. They first load the
8173 value stored at <tt>ptr</tt>. They then do the bitwise
8174 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
8175 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8176
8177<h5>Examples:</h5>
8178<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]8179%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8180%ptr = bitcast i8* %mallocP to i32*
8181 store i32 0x0F0F, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8182%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8183 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8184%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8185 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8186%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8187 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8188%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8189 <i>; yields {i32}:result3 = FF</i>
8190%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
8191</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8192
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8193</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8194
8195<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8196<h4>
8197 <a name="int_atomic_load_max">
8198 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
8199 </a>
8200 <br>
8201 <a name="int_atomic_load_min">
8202 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
8203 </a>
8204 <br>
8205 <a name="int_atomic_load_umax">
8206 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
8207 </a>
8208 <br>
8209 <a name="int_atomic_load_umin">
8210 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
8211 </a>
8212</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8213
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8214<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8215
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8216<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8217<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
8218 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
8219 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
8220 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8221
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8222<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8223 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8224 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8225 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8226 declare i64 @llvm.atomic.load.max.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8227</pre>
8228
8229<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8230 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8231 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8232 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8233 declare i64 @llvm.atomic.load.min.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8234</pre>
8235
8236<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8237 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8238 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8239 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8240 declare i64 @llvm.atomic.load.umax.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8241</pre>
8242
8243<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8244 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8245 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8246 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8247 declare i64 @llvm.atomic.load.umin.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8248</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8249
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8250<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]8251<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8252 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
8253 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8254
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8255<h5>Arguments:</h5>
8256<p>These intrinsics take two arguments, the first a pointer to an integer value
8257 and the second an integer value. The result is also an integer value. These
8258 integer types can have any bit width, but they must all have the same bit
8259 width. The targets may only lower integer representations they support.</p>
8260
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8261<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8262<p>These intrinsics does a series of operations atomically. They first load the
8263 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
8264 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
8265 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8266
8267<h5>Examples:</h5>
8268<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]8269%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8270%ptr = bitcast i8* %mallocP to i32*
8271 store i32 7, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8272%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8273 <i>; yields {i32}:result0 = 7</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8274%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8275 <i>; yields {i32}:result1 = -2</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8276%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8277 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8278%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8279 <i>; yields {i32}:result3 = 8</i>
8280%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
8281</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8282
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8283</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]8284
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8285</div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8286
8287<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8288<h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8289 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8290</h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8291
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8292<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8293
8294<p>This class of intrinsics exists to information about the lifetime of memory
8295 objects and ranges where variables are immutable.</p>
8296
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8297<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8298<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8299 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8300</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8301
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8302<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8303
8304<h5>Syntax:</h5>
8305<pre>
8306 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8307</pre>
8308
8309<h5>Overview:</h5>
8310<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
8311 object's lifetime.</p>
8312
8313<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8314<p>The first argument is a constant integer representing the size of the
8315 object, or -1 if it is variable sized. The second argument is a pointer to
8316 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8317
8318<h5>Semantics:</h5>
8319<p>This intrinsic indicates that before this point in the code, the value of the
8320 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
Nick Lewycky8d336592009-10-27 16:56:58 +0000[diff] [blame]8321 never be used and has an undefined value. A load from the pointer that
8322 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8323 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
8324
8325</div>
8326
8327<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8328<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8329 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8330</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8331
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8332<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8333
8334<h5>Syntax:</h5>
8335<pre>
8336 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8337</pre>
8338
8339<h5>Overview:</h5>
8340<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
8341 object's lifetime.</p>
8342
8343<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8344<p>The first argument is a constant integer representing the size of the
8345 object, or -1 if it is variable sized. The second argument is a pointer to
8346 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8347
8348<h5>Semantics:</h5>
8349<p>This intrinsic indicates that after this point in the code, the value of the
8350 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
8351 never be used and has an undefined value. Any stores into the memory object
8352 following this intrinsic may be removed as dead.
8353
8354</div>
8355
8356<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8357<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8358 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8359</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8360
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8361<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8362
8363<h5>Syntax:</h5>
8364<pre>
Nick Lewycky29b6cb42010-11-30 04:13:41 +0000[diff] [blame]8365 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8366</pre>
8367
8368<h5>Overview:</h5>
8369<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
8370 a memory object will not change.</p>
8371
8372<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8373<p>The first argument is a constant integer representing the size of the
8374 object, or -1 if it is variable sized. The second argument is a pointer to
8375 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8376
8377<h5>Semantics:</h5>
8378<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
8379 the return value, the referenced memory location is constant and
8380 unchanging.</p>
8381
8382</div>
8383
8384<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8385<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8386 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8387</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8388
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8389<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8390
8391<h5>Syntax:</h5>
8392<pre>
8393 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8394</pre>
8395
8396<h5>Overview:</h5>
8397<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
8398 a memory object are mutable.</p>
8399
8400<h5>Arguments:</h5>
8401<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8402 The second argument is a constant integer representing the size of the
8403 object, or -1 if it is variable sized and the third argument is a pointer
8404 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8405
8406<h5>Semantics:</h5>
8407<p>This intrinsic indicates that the memory is mutable again.</p>
8408
8409</div>
8410
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8411</div>
8412
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]8413<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8414<h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8415 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8416</h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8417
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8418<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8419
8420<p>This class of intrinsics is designed to be generic and has no specific
8421 purpose.</p>
8422
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8423<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8424<h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8425 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8426</h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8427
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8428<div>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8429
8430<h5>Syntax:</h5>
8431<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8432 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8433</pre>
8434
8435<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8436<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8437
8438<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8439<p>The first argument is a pointer to a value, the second is a pointer to a
8440 global string, the third is a pointer to a global string which is the source
8441 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8442
8443<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8444<p>This intrinsic allows annotation of local variables with arbitrary strings.
8445 This can be useful for special purpose optimizations that want to look for
John Criswelle865c032011-08-19 16:57:55 +0000[diff] [blame]8446 these annotations. These have no other defined use; they are ignored by code
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8447 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8448
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8449</div>
8450
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8451<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8452<h4>
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]8453 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8454</h4>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8455
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8456<div>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8457
8458<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8459<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
8460 any integer bit width.</p>
8461
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8462<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8463 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8464 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8465 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8466 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8467 declare i256 @llvm.annotation.i256(i256 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8468</pre>
8469
8470<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8471<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8472
8473<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8474<p>The first argument is an integer value (result of some expression), the
8475 second is a pointer to a global string, the third is a pointer to a global
8476 string which is the source file name, and the last argument is the line
8477 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8478
8479<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8480<p>This intrinsic allows annotations to be put on arbitrary expressions with
8481 arbitrary strings. This can be useful for special purpose optimizations that
John Criswelle865c032011-08-19 16:57:55 +0000[diff] [blame]8482 want to look for these annotations. These have no other defined use; they
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8483 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8484
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8485</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]8486
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8487<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8488<h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8489 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8490</h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8491
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8492<div>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8493
8494<h5>Syntax:</h5>
8495<pre>
8496 declare void @llvm.trap()
8497</pre>
8498
8499<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8500<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8501
8502<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8503<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8504
8505<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8506<p>This intrinsics is lowered to the target dependent trap instruction. If the
8507 target does not have a trap instruction, this intrinsic will be lowered to
8508 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8509
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8510</div>
8511
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8512<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8513<h4>
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]8514 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8515</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8516
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8517<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8518
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8519<h5>Syntax:</h5>
8520<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8521 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8522</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8523
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8524<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8525<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8526 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8527 ensure that it is placed on the stack before local variables.</p>
8528
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8529<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8530<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8531 arguments. The first argument is the value loaded from the stack
8532 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8533 that has enough space to hold the value of the guard.</p>
8534
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8535<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8536<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8537 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8538 stack. This is to ensure that if a local variable on the stack is
8539 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8540 the guard on the stack is checked against the original guard. If they are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8541 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8542 function.</p>
8543
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8544</div>
8545
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8546<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8547<h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8548 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8549</h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8550
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8551<div>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8552
8553<h5>Syntax:</h5>
8554<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8555 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8556 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8557</pre>
8558
8559<h5>Overview:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8560<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8561 the optimizers to determine at compile time whether a) an operation (like
8562 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8563 runtime check for overflow isn't necessary. An object in this context means
8564 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8565
8566<h5>Arguments:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8567<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]8568 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8569 is a boolean 0 or 1. This argument determines whether you want the
8570 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]8571 1, variables are not allowed.</p>
8572
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8573<h5>Semantics:</h5>
8574<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8575 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8576 depending on the <tt>type</tt> argument, if the size cannot be determined at
8577 compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8578
8579</div>
8580
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8581</div>
8582
8583</div>
8584
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8585<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8586<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8587<address>
8588 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8590 <a href="http://validator.w3.org/check/referer"><img
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Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8592
8593 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]8594 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8595 Last modified: $Date$
8596</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]8597
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]8598</body>
8599</html>