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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / e6e8826870bee3facb04f950f0bd725f8a88623d / . / docs / LangRef.html
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4<head>
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 Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]278 <li><a href="#int_trampoline">Trampoline Intrinsic</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 Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]281 </ol>
282 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]283 <li><a href="#int_atomics">Atomic intrinsics</a>
284 <ol>
285 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
286 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
287 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
288 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
289 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
290 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
291 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
292 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
293 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
294 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
295 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
296 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
297 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
298 </ol>
299 </li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]300 <li><a href="#int_memorymarkers">Memory Use Markers</a>
301 <ol>
302 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
303 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
304 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
305 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
306 </ol>
307 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]308 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]309 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]310 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]311 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]312 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]313 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]314 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]315 '<tt>llvm.trap</tt>' Intrinsic</a></li>
316 <li><a href="#int_stackprotector">
317 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]318 <li><a href="#int_objectsize">
319 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]320 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]321 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]322 </ol>
323 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]324</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]325
326<div class="doc_author">
327 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
328 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]329</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]330
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]331<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]332<h2><a name="abstract">Abstract</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]333<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]334
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]335<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]336
337<p>This document is a reference manual for the LLVM assembly language. LLVM is
338 a Static Single Assignment (SSA) based representation that provides type
339 safety, low-level operations, flexibility, and the capability of representing
340 'all' high-level languages cleanly. It is the common code representation
341 used throughout all phases of the LLVM compilation strategy.</p>
342
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]343</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]344
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]345<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]346<h2><a name="introduction">Introduction</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]347<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]348
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]349<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]350
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]351<p>The LLVM code representation is designed to be used in three different forms:
352 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
353 for fast loading by a Just-In-Time compiler), and as a human readable
354 assembly language representation. This allows LLVM to provide a powerful
355 intermediate representation for efficient compiler transformations and
356 analysis, while providing a natural means to debug and visualize the
357 transformations. The three different forms of LLVM are all equivalent. This
358 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]359
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]360<p>The LLVM representation aims to be light-weight and low-level while being
361 expressive, typed, and extensible at the same time. It aims to be a
362 "universal IR" of sorts, by being at a low enough level that high-level ideas
363 may be cleanly mapped to it (similar to how microprocessors are "universal
364 IR's", allowing many source languages to be mapped to them). By providing
365 type information, LLVM can be used as the target of optimizations: for
366 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]367 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]368 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]369
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]370<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]371<h4>
372 <a name="wellformed">Well-Formedness</a>
373</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]374
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]375<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]376
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]377<p>It is important to note that this document describes 'well formed' LLVM
378 assembly language. There is a difference between what the parser accepts and
379 what is considered 'well formed'. For example, the following instruction is
380 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]381
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]382<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]383%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]384</pre>
385
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]386<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
387 LLVM infrastructure provides a verification pass that may be used to verify
388 that an LLVM module is well formed. This pass is automatically run by the
389 parser after parsing input assembly and by the optimizer before it outputs
390 bitcode. The violations pointed out by the verifier pass indicate bugs in
391 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]392
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]393</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]394
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]395</div>
396
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]397<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]398
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]399<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]400<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]401<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]402
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]403<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]404
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]405<p>LLVM identifiers come in two basic types: global and local. Global
406 identifiers (functions, global variables) begin with the <tt>'@'</tt>
407 character. Local identifiers (register names, types) begin with
408 the <tt>'%'</tt> character. Additionally, there are three different formats
409 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]410
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]411<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]412 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]413 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
414 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
415 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
416 other characters in their names can be surrounded with quotes. Special
417 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
418 ASCII code for the character in hexadecimal. In this way, any character
419 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]420
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]421 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]422 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]423
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]424 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]425 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]426</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]427
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]428<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]429 don't need to worry about name clashes with reserved words, and the set of
430 reserved words may be expanded in the future without penalty. Additionally,
431 unnamed identifiers allow a compiler to quickly come up with a temporary
432 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]433
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]434<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]435 languages. There are keywords for different opcodes
436 ('<tt><a href="#i_add">add</a></tt>',
437 '<tt><a href="#i_bitcast">bitcast</a></tt>',
438 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
439 ('<tt><a href="#t_void">void</a></tt>',
440 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
441 reserved words cannot conflict with variable names, because none of them
442 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]443
444<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]445 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]446
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]447<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]448
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]449<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]450%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]451</pre>
452
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]453<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]454
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]455<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]456%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]457</pre>
458
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]459<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]460
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]461<pre class="doc_code">
Gabor Greifec58f752009-10-28 13:05:07 +0000[diff] [blame]462%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
463%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]464%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]465</pre>
466
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]467<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
468 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]469
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]470<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]471 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]472 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]473
474 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]475 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]476
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]477 <li>Unnamed temporaries are numbered sequentially</li>
478</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]479
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]480<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]481 demonstrating instructions, we will follow an instruction with a comment that
482 defines the type and name of value produced. Comments are shown in italic
483 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]484
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]485</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]486
487<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]488<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]489<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]490<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]491<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]492<h3>
493 <a name="modulestructure">Module Structure</a>
494</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]495
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]496<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]497
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]498<p>LLVM programs are composed of "Module"s, each of which is a translation unit
499 of the input programs. Each module consists of functions, global variables,
500 and symbol table entries. Modules may be combined together with the LLVM
501 linker, which merges function (and global variable) definitions, resolves
502 forward declarations, and merges symbol table entries. Here is an example of
503 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]504
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]505<pre class="doc_code">
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]506<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckydb9cd762011-01-29 01:09:53 +0000[diff] [blame]507<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]508
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]509<i>; External declaration of the puts function</i>&nbsp;
510<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]511
512<i>; Definition of main function</i>
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]513define i32 @main() { <i>; i32()* </i>&nbsp;
514 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
515 %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]516
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]517 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
518 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
519 <a href="#i_ret">ret</a> i32 0&nbsp;
520}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]521
522<i>; Named metadata</i>
523!1 = metadata !{i32 41}
524!foo = !{!1, null}
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]525</pre>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]526
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]527<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]528 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]529 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]530 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
531 "<tt>foo"</tt>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]532
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]533<p>In general, a module is made up of a list of global values, where both
534 functions and global variables are global values. Global values are
535 represented by a pointer to a memory location (in this case, a pointer to an
536 array of char, and a pointer to a function), and have one of the
537 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]538
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]539</div>
540
541<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]542<h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]543 <a name="linkage">Linkage Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]544</h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]545
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]546<div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]547
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]548<p>All Global Variables and Functions have one of the following types of
549 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]550
551<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]552 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]553 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
554 by objects in the current module. In particular, linking code into a
555 module with an private global value may cause the private to be renamed as
556 necessary to avoid collisions. Because the symbol is private to the
557 module, all references can be updated. This doesn't show up in any symbol
558 table in the object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]559
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]560 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]561 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
562 assembler and evaluated by the linker. Unlike normal strong symbols, they
563 are removed by the linker from the final linked image (executable or
564 dynamic library).</dd>
565
566 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
567 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
568 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
569 linker. The symbols are removed by the linker from the final linked image
570 (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]571
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]572 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
573 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
574 of the object is not taken. For instance, functions that had an inline
575 definition, but the compiler decided not to inline it. Note,
576 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
577 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
578 visibility. The symbols are removed by the linker from the final linked
579 image (executable or dynamic library).</dd>
580
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]581 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling07d31772010-06-29 22:34:52 +0000[diff] [blame]582 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]583 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
584 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]585
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]586 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]587 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]588 into the object file corresponding to the LLVM module. They exist to
589 allow inlining and other optimizations to take place given knowledge of
590 the definition of the global, which is known to be somewhere outside the
591 module. Globals with <tt>available_externally</tt> linkage are allowed to
592 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
593 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]594
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]595 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]596 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]597 the same name when linkage occurs. This can be used to implement
598 some forms of inline functions, templates, or other code which must be
599 generated in each translation unit that uses it, but where the body may
600 be overridden with a more definitive definition later. Unreferenced
601 <tt>linkonce</tt> globals are allowed to be discarded. Note that
602 <tt>linkonce</tt> linkage does not actually allow the optimizer to
603 inline the body of this function into callers because it doesn't know if
604 this definition of the function is the definitive definition within the
605 program or whether it will be overridden by a stronger definition.
606 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
607 linkage.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]608
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]609 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]610 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
611 <tt>linkonce</tt> linkage, except that unreferenced globals with
612 <tt>weak</tt> linkage may not be discarded. This is used for globals that
613 are declared "weak" in C source code.</dd>
614
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]615 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]616 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
617 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
618 global scope.
619 Symbols with "<tt>common</tt>" linkage are merged in the same way as
620 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]621 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]622 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]623 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
624 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]625
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]626
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]627 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]628 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]629 pointer to array type. When two global variables with appending linkage
630 are linked together, the two global arrays are appended together. This is
631 the LLVM, typesafe, equivalent of having the system linker append together
632 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]633
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]634 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]635 <dd>The semantics of this linkage follow the ELF object file model: the symbol
636 is weak until linked, if not linked, the symbol becomes null instead of
637 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]638
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]639 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
640 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]641 <dd>Some languages allow differing globals to be merged, such as two functions
642 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]643 that only equivalent globals are ever merged (the "one definition rule"
644 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]645 and <tt>weak_odr</tt> linkage types to indicate that the global will only
646 be merged with equivalent globals. These linkage types are otherwise the
647 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]648
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]649 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]650 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]651 visible, meaning that it participates in linkage and can be used to
652 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]653</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]654
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]655<p>The next two types of linkage are targeted for Microsoft Windows platform
656 only. They are designed to support importing (exporting) symbols from (to)
657 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]658
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]659<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]660 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]661 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]662 or variable via a global pointer to a pointer that is set up by the DLL
663 exporting the symbol. On Microsoft Windows targets, the pointer name is
664 formed by combining <code>__imp_</code> and the function or variable
665 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]666
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]667 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]668 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]669 pointer to a pointer in a DLL, so that it can be referenced with the
670 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
671 name is formed by combining <code>__imp_</code> and the function or
672 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]673</dl>
674
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]675<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
676 another module defined a "<tt>.LC0</tt>" variable and was linked with this
677 one, one of the two would be renamed, preventing a collision. Since
678 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
679 declarations), they are accessible outside of the current module.</p>
680
681<p>It is illegal for a function <i>declaration</i> to have any linkage type
682 other than "externally visible", <tt>dllimport</tt>
683 or <tt>extern_weak</tt>.</p>
684
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]685<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]686 or <tt>weak_odr</tt> linkages.</p>
687
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]688</div>
689
690<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]691<h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]692 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]693</h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]694
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]695<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]696
697<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]698 and <a href="#i_invoke">invokes</a> can all have an optional calling
699 convention specified for the call. The calling convention of any pair of
700 dynamic caller/callee must match, or the behavior of the program is
701 undefined. The following calling conventions are supported by LLVM, and more
702 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]703
704<dl>
705 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]706 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]707 specified) matches the target C calling conventions. This calling
708 convention supports varargs function calls and tolerates some mismatch in
709 the declared prototype and implemented declaration of the function (as
710 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]711
712 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]713 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]714 (e.g. by passing things in registers). This calling convention allows the
715 target to use whatever tricks it wants to produce fast code for the
716 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]717 (Application Binary Interface).
718 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]719 when this or the GHC convention is used.</a> This calling convention
720 does not support varargs and requires the prototype of all callees to
721 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]722
723 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]724 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]725 as possible under the assumption that the call is not commonly executed.
726 As such, these calls often preserve all registers so that the call does
727 not break any live ranges in the caller side. This calling convention
728 does not support varargs and requires the prototype of all callees to
729 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]730
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]731 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
732 <dd>This calling convention has been implemented specifically for use by the
733 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
734 It passes everything in registers, going to extremes to achieve this by
735 disabling callee save registers. This calling convention should not be
736 used lightly but only for specific situations such as an alternative to
737 the <em>register pinning</em> performance technique often used when
738 implementing functional programming languages.At the moment only X86
739 supports this convention and it has the following limitations:
740 <ul>
741 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
742 floating point types are supported.</li>
743 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
744 6 floating point parameters.</li>
745 </ul>
746 This calling convention supports
747 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
748 requires both the caller and callee are using it.
749 </dd>
750
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]751 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]752 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]753 target-specific calling conventions to be used. Target specific calling
754 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]755</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]756
757<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]758 support Pascal conventions or any other well-known target-independent
759 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]760
761</div>
762
763<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]764<h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]765 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]766</h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]767
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]768<div>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]769
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]770<p>All Global Variables and Functions have one of the following visibility
771 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]772
773<dl>
774 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]775 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]776 that the declaration is visible to other modules and, in shared libraries,
777 means that the declared entity may be overridden. On Darwin, default
778 visibility means that the declaration is visible to other modules. Default
779 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]780
781 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]782 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]783 object if they are in the same shared object. Usually, hidden visibility
784 indicates that the symbol will not be placed into the dynamic symbol
785 table, so no other module (executable or shared library) can reference it
786 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]787
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]788 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]789 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]790 the dynamic symbol table, but that references within the defining module
791 will bind to the local symbol. That is, the symbol cannot be overridden by
792 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]793</dl>
794
795</div>
796
797<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]798<h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]799 <a name="namedtypes">Named Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]800</h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]801
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]802<div>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]803
804<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]805 it easier to read the IR and make the IR more condensed (particularly when
806 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]807
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]808<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]809%mytype = type { %mytype*, i32 }
810</pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]811
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]812<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattnerdc65f222010-08-17 23:26:04 +0000[diff] [blame]813 "<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]814 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]815
816<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]817 and that you can therefore specify multiple names for the same type. This
818 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
819 uses structural typing, the name is not part of the type. When printing out
820 LLVM IR, the printer will pick <em>one name</em> to render all types of a
821 particular shape. This means that if you have code where two different
822 source types end up having the same LLVM type, that the dumper will sometimes
823 print the "wrong" or unexpected type. This is an important design point and
824 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]825
826</div>
827
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]828<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]829<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]830 <a name="globalvars">Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]831</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]832
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]833<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]834
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]835<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]836 instead of run-time. Global variables may optionally be initialized, may
837 have an explicit section to be placed in, and may have an optional explicit
838 alignment specified. A variable may be defined as "thread_local", which
839 means that it will not be shared by threads (each thread will have a
840 separated copy of the variable). A variable may be defined as a global
841 "constant," which indicates that the contents of the variable
842 will <b>never</b> be modified (enabling better optimization, allowing the
843 global data to be placed in the read-only section of an executable, etc).
844 Note that variables that need runtime initialization cannot be marked
845 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]846
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]847<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
848 constant, even if the final definition of the global is not. This capability
849 can be used to enable slightly better optimization of the program, but
850 requires the language definition to guarantee that optimizations based on the
851 'constantness' are valid for the translation units that do not include the
852 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]853
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]854<p>As SSA values, global variables define pointer values that are in scope
855 (i.e. they dominate) all basic blocks in the program. Global variables
856 always define a pointer to their "content" type because they describe a
857 region of memory, and all memory objects in LLVM are accessed through
858 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]859
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]860<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
861 that the address is not significant, only the content. Constants marked
Rafael Espindolaa5eaa862011-01-15 08:20:57 +0000[diff] [blame]862 like this can be merged with other constants if they have the same
863 initializer. Note that a constant with significant address <em>can</em>
864 be merged with a <tt>unnamed_addr</tt> constant, the result being a
865 constant whose address is significant.</p>
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]866
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]867<p>A global variable may be declared to reside in a target-specific numbered
868 address space. For targets that support them, address spaces may affect how
869 optimizations are performed and/or what target instructions are used to
870 access the variable. The default address space is zero. The address space
871 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]872
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]873<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]874 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]875
Chris Lattnerce99fa92010-04-28 00:13:42 +0000[diff] [blame]876<p>An explicit alignment may be specified for a global, which must be a power
877 of 2. If not present, or if the alignment is set to zero, the alignment of
878 the global is set by the target to whatever it feels convenient. If an
879 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner2d4b8ee2010-04-28 00:31:12 +0000[diff] [blame]880 alignment. Targets and optimizers are not allowed to over-align the global
881 if the global has an assigned section. In this case, the extra alignment
882 could be observable: for example, code could assume that the globals are
883 densely packed in their section and try to iterate over them as an array,
884 alignment padding would break this iteration.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]885
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]886<p>For example, the following defines a global in a numbered address space with
887 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]888
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]889<pre class="doc_code">
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]890@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]891</pre>
892
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]893</div>
894
895
896<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]897<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]898 <a name="functionstructure">Functions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]899</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]900
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]901<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]902
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]903<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]904 optional <a href="#linkage">linkage type</a>, an optional
905 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]906 <a href="#callingconv">calling convention</a>,
907 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]908 <a href="#paramattrs">parameter attribute</a> for the return type, a function
909 name, a (possibly empty) argument list (each with optional
910 <a href="#paramattrs">parameter attributes</a>), optional
911 <a href="#fnattrs">function attributes</a>, an optional section, an optional
912 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
913 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]914
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]915<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
916 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]917 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]918 <a href="#callingconv">calling convention</a>,
919 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]920 <a href="#paramattrs">parameter attribute</a> for the return type, a function
921 name, a possibly empty list of arguments, an optional alignment, and an
922 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]923
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]924<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]925 (Control Flow Graph) for the function. Each basic block may optionally start
926 with a label (giving the basic block a symbol table entry), contains a list
927 of instructions, and ends with a <a href="#terminators">terminator</a>
928 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]929
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]930<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]931 executed on entrance to the function, and it is not allowed to have
932 predecessor basic blocks (i.e. there can not be any branches to the entry
933 block of a function). Because the block can have no predecessors, it also
934 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]935
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]936<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]937 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]938
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]939<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]940 the alignment is set to zero, the alignment of the function is set by the
941 target to whatever it feels convenient. If an explicit alignment is
942 specified, the function is forced to have at least that much alignment. All
943 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]944
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]945<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
946 be significant and two identical functions can be merged</p>.
947
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]948<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]949<pre class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]950define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]951 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
952 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
953 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
954 [<a href="#gc">gc</a>] { ... }
955</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]956
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]957</div>
958
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]959<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]960<h3>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]961 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]962</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]963
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]964<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]965
966<p>Aliases act as "second name" for the aliasee value (which can be either
967 function, global variable, another alias or bitcast of global value). Aliases
968 may have an optional <a href="#linkage">linkage type</a>, and an
969 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]970
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]971<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]972<pre class="doc_code">
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]973@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]974</pre>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]975
976</div>
977
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]978<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]979<h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]980 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]981</h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]982
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]983<div>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]984
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]985<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]986 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]987 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]988
989<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]990<pre class="doc_code">
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]991; Some unnamed metadata nodes, which are referenced by the named metadata.
992!0 = metadata !{metadata !"zero"}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]993!1 = metadata !{metadata !"one"}
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]994!2 = metadata !{metadata !"two"}
Dan Gohman1005bc52010-07-13 19:48:13 +0000[diff] [blame]995; A named metadata.
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]996!name = !{!0, !1, !2}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]997</pre>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]998
999</div>
1000
1001<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1002<h3>
1003 <a name="paramattrs">Parameter Attributes</a>
1004</h3>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1005
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1006<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1007
1008<p>The return type and each parameter of a function type may have a set of
1009 <i>parameter attributes</i> associated with them. Parameter attributes are
1010 used to communicate additional information about the result or parameters of
1011 a function. Parameter attributes are considered to be part of the function,
1012 not of the function type, so functions with different parameter attributes
1013 can have the same function type.</p>
1014
1015<p>Parameter attributes are simple keywords that follow the type specified. If
1016 multiple parameter attributes are needed, they are space separated. For
1017 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1018
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1019<pre class="doc_code">
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]1020declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]1021declare i32 @atoi(i8 zeroext)
1022declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1023</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1024
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1025<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1026 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1027
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1028<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1029
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1030<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1031 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1032 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichebe81732011-03-16 22:20:18 +0000[diff] [blame]1033 should be zero-extended to the extent required by the target's ABI (which
1034 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1035 parameter) or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1036
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1037 <dt><tt><b>signext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1038 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich9e69ff92011-03-17 14:21:58 +0000[diff] [blame]1039 should be sign-extended to the extent required by the target's ABI (which
1040 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1041 return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1042
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1043 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1044 <dd>This indicates that this parameter or return value should be treated in a
1045 special target-dependent fashion during while emitting code for a function
1046 call or return (usually, by putting it in a register as opposed to memory,
1047 though some targets use it to distinguish between two different kinds of
1048 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1049
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1050 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1051 <dd><p>This indicates that the pointer parameter should really be passed by
1052 value to the function. The attribute implies that a hidden copy of the
1053 pointee
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1054 is made between the caller and the callee, so the callee is unable to
1055 modify the value in the callee. This attribute is only valid on LLVM
1056 pointer arguments. It is generally used to pass structs and arrays by
1057 value, but is also valid on pointers to scalars. The copy is considered
1058 to belong to the caller not the callee (for example,
1059 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1060 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1061 values.</p>
1062
1063 <p>The byval attribute also supports specifying an alignment with
1064 the align attribute. It indicates the alignment of the stack slot to
1065 form and the known alignment of the pointer specified to the call site. If
1066 the alignment is not specified, then the code generator makes a
1067 target-specific assumption.</p></dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1068
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1069 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1070 <dd>This indicates that the pointer parameter specifies the address of a
1071 structure that is the return value of the function in the source program.
1072 This pointer must be guaranteed by the caller to be valid: loads and
1073 stores to the structure may be assumed by the callee to not to trap. This
1074 may only be applied to the first parameter. This is not a valid attribute
1075 for return values. </dd>
1076
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1077 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1078 <dd>This indicates that pointer values
1079 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmanefca7f92010-07-02 23:46:54 +0000[diff] [blame]1080 value do not alias pointer values which are not <i>based</i> on it,
1081 ignoring certain "irrelevant" dependencies.
1082 For a call to the parent function, dependencies between memory
1083 references from before or after the call and from those during the call
1084 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1085 return value used in that call.
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1086 The caller shares the responsibility with the callee for ensuring that
1087 these requirements are met.
1088 For further details, please see the discussion of the NoAlias response in
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1089 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1090<br>
John McCall191d4ee2010-07-06 21:07:14 +0000[diff] [blame]1091 Note that this definition of <tt>noalias</tt> is intentionally
1092 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner211244a2010-07-06 20:51:35 +0000[diff] [blame]1093 arguments, though it is slightly weaker.
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1094<br>
1095 For function return values, C99's <tt>restrict</tt> is not meaningful,
1096 while LLVM's <tt>noalias</tt> is.
1097 </dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1098
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1099 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1100 <dd>This indicates that the callee does not make any copies of the pointer
1101 that outlive the callee itself. This is not a valid attribute for return
1102 values.</dd>
1103
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1104 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1105 <dd>This indicates that the pointer parameter can be excised using the
1106 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1107 attribute for return values.</dd>
1108</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1109
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1110</div>
1111
1112<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1113<h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1114 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1115</h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1116
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1117<div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1118
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1119<p>Each function may specify a garbage collector name, which is simply a
1120 string:</p>
1121
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1122<pre class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1123define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1124</pre>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1125
1126<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1127 collector which will cause the compiler to alter its output in order to
1128 support the named garbage collection algorithm.</p>
1129
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1130</div>
1131
1132<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1133<h3>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1134 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1135</h3>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1136
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1137<div>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1138
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1139<p>Function attributes are set to communicate additional information about a
1140 function. Function attributes are considered to be part of the function, not
1141 of the function type, so functions with different parameter attributes can
1142 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1143
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1144<p>Function attributes are simple keywords that follow the type specified. If
1145 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1146
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1147<pre class="doc_code">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1148define void @f() noinline { ... }
1149define void @f() alwaysinline { ... }
1150define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1151define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1152</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1153
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1154<dl>
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1155 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1156 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1157 the backend should forcibly align the stack pointer. Specify the
1158 desired alignment, which must be a power of two, in parentheses.
1159
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1160 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1161 <dd>This attribute indicates that the inliner should attempt to inline this
1162 function into callers whenever possible, ignoring any active inlining size
1163 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1164
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1165 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis6f12e292010-10-25 16:29:03 +0000[diff] [blame]1166 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis0076d202010-10-25 19:07:39 +0000[diff] [blame]1167 meaning the function can be patched and/or hooked even while it is
1168 loaded into memory. On x86, the function prologue will be preceded
1169 by six bytes of padding and will begin with a two-byte instruction.
1170 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1171 higher were compiled in this fashion.</dd>
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1172
Dan Gohman129bd562011-06-16 16:03:13 +0000[diff] [blame]1173 <dt><tt><b>nonlazybind</b></tt></dt>
1174 <dd>This attribute suppresses lazy symbol binding for the function. This
1175 may make calls to the function faster, at the cost of extra program
1176 startup time if the function is not called during program startup.</dd>
1177
Jakob Stoklund Olesen570a4a52010-02-06 01:16:28 +0000[diff] [blame]1178 <dt><tt><b>inlinehint</b></tt></dt>
1179 <dd>This attribute indicates that the source code contained a hint that inlining
1180 this function is desirable (such as the "inline" keyword in C/C++). It
1181 is just a hint; it imposes no requirements on the inliner.</dd>
1182
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1183 <dt><tt><b>naked</b></tt></dt>
1184 <dd>This attribute disables prologue / epilogue emission for the function.
1185 This can have very system-specific consequences.</dd>
1186
1187 <dt><tt><b>noimplicitfloat</b></tt></dt>
1188 <dd>This attributes disables implicit floating point instructions.</dd>
1189
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1190 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1191 <dd>This attribute indicates that the inliner should never inline this
1192 function in any situation. This attribute may not be used together with
1193 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1194
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1195 <dt><tt><b>noredzone</b></tt></dt>
1196 <dd>This attribute indicates that the code generator should not use a red
1197 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1198
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1199 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1200 <dd>This function attribute indicates that the function never returns
1201 normally. This produces undefined behavior at runtime if the function
1202 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1203
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1204 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1205 <dd>This function attribute indicates that the function never returns with an
1206 unwind or exceptional control flow. If the function does unwind, its
1207 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1208
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1209 <dt><tt><b>optsize</b></tt></dt>
1210 <dd>This attribute suggests that optimization passes and code generator passes
1211 make choices that keep the code size of this function low, and otherwise
1212 do optimizations specifically to reduce code size.</dd>
1213
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1214 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1215 <dd>This attribute indicates that the function computes its result (or decides
1216 to unwind an exception) based strictly on its arguments, without
1217 dereferencing any pointer arguments or otherwise accessing any mutable
1218 state (e.g. memory, control registers, etc) visible to caller functions.
1219 It does not write through any pointer arguments
1220 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1221 changes any state visible to callers. This means that it cannot unwind
1222 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1223 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1224
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1225 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1226 <dd>This attribute indicates that the function does not write through any
1227 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1228 arguments) or otherwise modify any state (e.g. memory, control registers,
1229 etc) visible to caller functions. It may dereference pointer arguments
1230 and read state that may be set in the caller. A readonly function always
1231 returns the same value (or unwinds an exception identically) when called
1232 with the same set of arguments and global state. It cannot unwind an
1233 exception by calling the <tt>C++</tt> exception throwing methods, but may
1234 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1235
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1236 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1237 <dd>This attribute indicates that the function should emit a stack smashing
1238 protector. It is in the form of a "canary"&mdash;a random value placed on
1239 the stack before the local variables that's checked upon return from the
1240 function to see if it has been overwritten. A heuristic is used to
1241 determine if a function needs stack protectors or not.<br>
1242<br>
1243 If a function that has an <tt>ssp</tt> attribute is inlined into a
1244 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1245 function will have an <tt>ssp</tt> attribute.</dd>
1246
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1247 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1248 <dd>This attribute indicates that the function should <em>always</em> emit a
1249 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1250 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1251<br>
1252 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1253 function that doesn't have an <tt>sspreq</tt> attribute or which has
1254 an <tt>ssp</tt> attribute, then the resulting function will have
1255 an <tt>sspreq</tt> attribute.</dd>
Rafael Espindolafbff0ec2011-07-25 15:27:59 +0000[diff] [blame]1256
1257 <dt><tt><b><a name="uwtable">uwtable</a></b></tt></dt>
1258 <dd>This attribute indicates that the ABI being targeted requires that
1259 an unwind table entry be produce for this function even if we can
1260 show that no exceptions passes by it. This is normally the case for
1261 the ELF x86-64 abi, but it can be disabled for some compilation
1262 units.</dd>
1263
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1264</dl>
1265
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1266</div>
1267
1268<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1269<h3>
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1270 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1271</h3>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1272
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1273<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1274
1275<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1276 the GCC "file scope inline asm" blocks. These blocks are internally
1277 concatenated by LLVM and treated as a single unit, but may be separated in
1278 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1279
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1280<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1281module asm "inline asm code goes here"
1282module asm "more can go here"
1283</pre>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1284
1285<p>The strings can contain any character by escaping non-printable characters.
1286 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]1287 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1288
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1289<p>The inline asm code is simply printed to the machine code .s file when
1290 assembly code is generated.</p>
1291
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1292</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1293
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1294<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1295<h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1296 <a name="datalayout">Data Layout</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1297</h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1298
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1299<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1300
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1301<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1302 data is to be laid out in memory. The syntax for the data layout is
1303 simply:</p>
1304
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1305<pre class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1306target datalayout = "<i>layout specification</i>"
1307</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1308
1309<p>The <i>layout specification</i> consists of a list of specifications
1310 separated by the minus sign character ('-'). Each specification starts with
1311 a letter and may include other information after the letter to define some
1312 aspect of the data layout. The specifications accepted are as follows:</p>
1313
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1314<dl>
1315 <dt><tt>E</tt></dt>
1316 <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]1317 bits with the most significance have the lowest address location.</dd>
1318
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1319 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1320 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1321 the bits with the least significance have the lowest address
1322 location.</dd>
1323
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1324 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1325 <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]1326 <i>preferred</i> alignments. All sizes are in bits. Specifying
1327 the <i>pref</i> alignment is optional. If omitted, the
1328 preceding <tt>:</tt> should be omitted too.</dd>
1329
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1330 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1331 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1332 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1333
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1334 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1335 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1336 <i>size</i>.</dd>
1337
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1338 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1339 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesen9d8d2212010-05-28 18:54:47 +0000[diff] [blame]1340 <i>size</i>. Only values of <i>size</i> that are supported by the target
1341 will work. 32 (float) and 64 (double) are supported on all targets;
1342 80 or 128 (different flavors of long double) are also supported on some
1343 targets.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1344
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1345 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1346 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1347 <i>size</i>.</dd>
1348
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1349 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1350 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1351 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1352
1353 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1354 <dd>This specifies a set of native integer widths for the target CPU
1355 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1356 "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]1357 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1358 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1359</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1360
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1361<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]1362 default set of specifications which are then (possibly) overridden by the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1363 specifications in the <tt>datalayout</tt> keyword. The default specifications
1364 are given in this list:</p>
1365
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1366<ul>
1367 <li><tt>E</tt> - big endian</li>
Dan Gohmanfdf2e8c2010-02-23 02:44:03 +0000[diff] [blame]1368 <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]1369 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1370 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1371 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1372 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1373 <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]1374 alignment of 64-bits</li>
1375 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1376 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1377 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1378 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1379 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1380 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1381</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1382
1383<p>When LLVM is determining the alignment for a given type, it uses the
1384 following rules:</p>
1385
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1386<ol>
1387 <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]1388 specification is used.</li>
1389
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1390 <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]1391 smallest integer type that is larger than the bitwidth of the sought type
1392 is used. If none of the specifications are larger than the bitwidth then
1393 the the largest integer type is used. For example, given the default
1394 specifications above, the i7 type will use the alignment of i8 (next
1395 largest) while both i65 and i256 will use the alignment of i64 (largest
1396 specified).</li>
1397
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1398 <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]1399 largest vector type that is smaller than the sought vector type will be
1400 used as a fall back. This happens because &lt;128 x double&gt; can be
1401 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1402</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1403
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1404</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1405
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1406<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1407<h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1408 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1409</h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1410
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1411<div>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1412
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1413<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1414with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1415is undefined. Pointer values are associated with address ranges
1416according to the following rules:</p>
1417
1418<ul>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1419 <li>A pointer value is associated with the addresses associated with
1420 any value it is <i>based</i> on.
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1421 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1422 range of the variable's storage.</li>
1423 <li>The result value of an allocation instruction is associated with
1424 the address range of the allocated storage.</li>
1425 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1426 no address.</li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1427 <li>An integer constant other than zero or a pointer value returned
1428 from a function not defined within LLVM may be associated with address
1429 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1430 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1431 allocated by mechanisms provided by LLVM.</li>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1432</ul>
1433
1434<p>A pointer value is <i>based</i> on another pointer value according
1435 to the following rules:</p>
1436
1437<ul>
1438 <li>A pointer value formed from a
1439 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1440 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1441 <li>The result value of a
1442 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1443 of the <tt>bitcast</tt>.</li>
1444 <li>A pointer value formed by an
1445 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1446 pointer values that contribute (directly or indirectly) to the
1447 computation of the pointer's value.</li>
1448 <li>The "<i>based</i> on" relationship is transitive.</li>
1449</ul>
1450
1451<p>Note that this definition of <i>"based"</i> is intentionally
1452 similar to the definition of <i>"based"</i> in C99, though it is
1453 slightly weaker.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1454
1455<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1456<tt><a href="#i_load">load</a></tt> merely indicates the size and
1457alignment of the memory from which to load, as well as the
Dan Gohmanc22c0f32010-06-17 19:23:50 +0000[diff] [blame]1458interpretation of the value. The first operand type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1459<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1460and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1461
1462<p>Consequently, type-based alias analysis, aka TBAA, aka
1463<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1464LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1465additional information which specialized optimization passes may use
1466to implement type-based alias analysis.</p>
1467
1468</div>
1469
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1470<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1471<h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1472 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1473</h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1474
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1475<div>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1476
1477<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1478href="#i_store"><tt>store</tt></a>s, and <a
1479href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1480The optimizers must not change the number of volatile operations or change their
1481order of execution relative to other volatile operations. The optimizers
1482<i>may</i> change the order of volatile operations relative to non-volatile
1483operations. This is not Java's "volatile" and has no cross-thread
1484synchronization behavior.</p>
1485
1486</div>
1487
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1488<!-- ======================================================================= -->
1489<h3>
1490 <a name="memmodel">Memory Model for Concurrent Operations</a>
1491</h3>
1492
1493<div>
1494
1495<p>The LLVM IR does not define any way to start parallel threads of execution
1496or to register signal handlers. Nonetheless, there are platform-specific
1497ways to create them, and we define LLVM IR's behavior in their presence. This
1498model is inspired by the C++0x memory model.</p>
1499
1500<p>We define a <i>happens-before</i> partial order as the least partial order
1501that</p>
1502<ul>
1503 <li>Is a superset of single-thread program order, and</li>
1504 <li>When a <i>synchronizes-with</i> <tt>b</tt>, includes an edge from
1505 <tt>a</tt> to <tt>b</tt>. <i>Synchronizes-with</i> pairs are introduced
1506 by platform-specific techniques, like pthread locks, thread
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1507 creation, thread joining, etc., and by atomic instructions.
1508 (See also <a href="#ordering">Atomic Memory Ordering Constraints</a>).
1509 </li>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1510</ul>
1511
1512<p>Note that program order does not introduce <i>happens-before</i> edges
1513between a thread and signals executing inside that thread.</p>
1514
1515<p>Every (defined) read operation (load instructions, memcpy, atomic
1516loads/read-modify-writes, etc.) <var>R</var> reads a series of bytes written by
1517(defined) write operations (store instructions, atomic
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1518stores/read-modify-writes, memcpy, etc.). For the purposes of this section,
1519initialized globals are considered to have a write of the initializer which is
1520atomic and happens before any other read or write of the memory in question.
1521For each byte of a read <var>R</var>, <var>R<sub>byte</sub></var> may see
1522any write to the same byte, except:</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1523
1524<ul>
1525 <li>If <var>write<sub>1</sub></var> happens before
1526 <var>write<sub>2</sub></var>, and <var>write<sub>2</sub></var> happens
1527 before <var>R<sub>byte</sub></var>, then <var>R<sub>byte</sub></var>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1528 does not see <var>write<sub>1</sub></var>.
Bill Wendling0246bb72011-07-31 06:45:03 +0000[diff] [blame]1529 <li>If <var>R<sub>byte</sub></var> happens before
1530 <var>write<sub>3</sub></var>, then <var>R<sub>byte</sub></var> does not
1531 see <var>write<sub>3</sub></var>.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1532</ul>
1533
1534<p>Given that definition, <var>R<sub>byte</sub></var> is defined as follows:
1535<ul>
1536 <li>If there is no write to the same byte that happens before
1537 <var>R<sub>byte</sub></var>, <var>R<sub>byte</sub></var> returns
1538 <tt>undef</tt> for that byte.
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1539 <li>Otherwise, if <var>R<sub>byte</sub></var> may see exactly one write,
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1540 <var>R<sub>byte</sub></var> returns the value written by that
1541 write.</li>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1542 <li>Otherwise, if <var>R</var> is atomic, and all the writes
1543 <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]1544 values written. See the <a href="#ordering">Atomic Memory Ordering
1545 Constraints</a> section for additional constraints on how the choice
1546 is made.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1547 <li>Otherwise <var>R<sub>byte</sub></var> returns <tt>undef</tt>.</li>
1548</ul>
1549
1550<p><var>R</var> returns the value composed of the series of bytes it read.
1551This implies that some bytes within the value may be <tt>undef</tt>
1552<b>without</b> the entire value being <tt>undef</tt>. Note that this only
1553defines the semantics of the operation; it doesn't mean that targets will
1554emit more than one instruction to read the series of bytes.</p>
1555
1556<p>Note that in cases where none of the atomic intrinsics are used, this model
1557places only one restriction on IR transformations on top of what is required
1558for single-threaded execution: introducing a store to a byte which might not
Eli Friedman101c81d2011-08-02 01:15:34 +0000[diff] [blame]1559otherwise be stored is not allowed in general. (Specifically, in the case
1560where another thread might write to and read from an address, introducing a
1561store can change a load that may see exactly one write into a load that may
1562see multiple writes.)</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1563
1564<!-- FIXME: This model assumes all targets where concurrency is relevant have
1565a byte-size store which doesn't affect adjacent bytes. As far as I can tell,
1566none of the backends currently in the tree fall into this category; however,
1567there might be targets which care. If there are, we want a paragraph
1568like the following:
1569
1570Targets may specify that stores narrower than a certain width are not
1571available; on such a target, for the purposes of this model, treat any
1572non-atomic write with an alignment or width less than the minimum width
1573as if it writes to the relevant surrounding bytes.
1574-->
1575
1576</div>
1577
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1578<!-- ======================================================================= -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]1579<h3>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1580 <a name="ordering">Atomic Memory Ordering Constraints</a>
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]1581</h3>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1582
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]1583<div>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1584
1585<p>Atomic instructions (<a href="#i_cmpxchg"><code>cmpxchg</code></a>,
Eli Friedman21006d42011-08-09 23:02:53 +0000[diff] [blame]1586<a href="#i_atomicrmw"><code>atomicrmw</code></a>,
1587<a href="#i_fence"><code>fence</code></a>,
1588<a href="#i_load"><code>atomic load</code></a>, and
Eli Friedman8fa281a2011-08-09 23:26:12 +0000[diff] [blame]1589<a href="#i_store"><code>atomic store</code></a>) take an ordering parameter
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1590that determines which other atomic instructions on the same address they
1591<i>synchronize with</i>. These semantics are borrowed from Java and C++0x,
1592but are somewhat more colloquial. If these descriptions aren't precise enough,
1593check those specs. <a href="#i_fence"><code>fence</code></a> instructions
1594treat these orderings somewhat differently since they don't take an address.
1595See that instruction's documentation for details.</p>
1596
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1597<dl>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1598<dt><code>unordered</code></dt>
1599<dd>The set of values that can be read is governed by the happens-before
1600partial order. A value cannot be read unless some operation wrote it.
1601This is intended to provide a guarantee strong enough to model Java's
1602non-volatile shared variables. This ordering cannot be specified for
1603read-modify-write operations; it is not strong enough to make them atomic
1604in any interesting way.</dd>
1605<dt><code>monotonic</code></dt>
1606<dd>In addition to the guarantees of <code>unordered</code>, there is a single
1607total order for modifications by <code>monotonic</code> operations on each
1608address. All modification orders must be compatible with the happens-before
1609order. There is no guarantee that the modification orders can be combined to
1610a global total order for the whole program (and this often will not be
1611possible). The read in an atomic read-modify-write operation
1612(<a href="#i_cmpxchg"><code>cmpxchg</code></a> and
1613<a href="#i_atomicrmw"><code>atomicrmw</code></a>)
1614reads the value in the modification order immediately before the value it
1615writes. If one atomic read happens before another atomic read of the same
1616address, the later read must see the same value or a later value in the
1617address's modification order. This disallows reordering of
1618<code>monotonic</code> (or stronger) operations on the same address. If an
1619address is written <code>monotonic</code>ally by one thread, and other threads
1620<code>monotonic</code>ally read that address repeatedly, the other threads must
1621eventually see the write. This is intended to model C++'s relaxed atomic
1622variables.</dd>
1623<dt><code>acquire</code></dt>
1624<dd>In addition to the guarantees of <code>monotonic</code>, if this operation
1625reads a value written by a <code>release</code> atomic operation, it
1626<i>synchronizes-with</i> that operation.</dd>
1627<dt><code>release</code></dt>
1628<dd>In addition to the guarantees of <code>monotonic</code>,
1629a <i>synchronizes-with</i> edge may be formed by an <code>acquire</code>
1630operation.</dd>
1631<dt><code>acq_rel</code> (acquire+release)</dt><dd>Acts as both an
1632<code>acquire</code> and <code>release</code> operation on its address.</dd>
1633<dt><code>seq_cst</code> (sequentially consistent)</dt><dd>
1634<dd>In addition to the guarantees of <code>acq_rel</code>
1635(<code>acquire</code> for an operation which only reads, <code>release</code>
1636for an operation which only writes), there is a global total order on all
1637sequentially-consistent operations on all addresses, which is consistent with
1638the <i>happens-before</i> partial order and with the modification orders of
1639all the affected addresses. Each sequentially-consistent read sees the last
1640preceding write to the same address in this global order. This is intended
1641to model C++'s sequentially-consistent atomic variables and Java's volatile
1642shared variables.</dd>
1643</dl>
1644
1645<p id="singlethread">If an atomic operation is marked <code>singlethread</code>,
1646it only <i>synchronizes with</i> or participates in modification and seq_cst
1647total orderings with other operations running in the same thread (for example,
1648in signal handlers).</p>
1649
1650</div>
1651
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1652</div>
1653
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1654<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1655<h2><a name="typesystem">Type System</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1656<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1657
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1658<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1659
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1660<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1661 intermediate representation. Being typed enables a number of optimizations
1662 to be performed on the intermediate representation directly, without having
1663 to do extra analyses on the side before the transformation. A strong type
1664 system makes it easier to read the generated code and enables novel analyses
1665 and transformations that are not feasible to perform on normal three address
1666 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1667
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1668<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1669<h3>
1670 <a name="t_classifications">Type Classifications</a>
1671</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1672
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1673<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1674
1675<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1676
1677<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1678 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1679 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1680 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1681 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1682 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1683 </tr>
1684 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1685 <td><a href="#t_floating">floating point</a></td>
1686 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1687 </tr>
1688 <tr>
1689 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1690 <td><a href="#t_integer">integer</a>,
1691 <a href="#t_floating">floating point</a>,
1692 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1693 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1694 <a href="#t_struct">structure</a>,
1695 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1696 <a href="#t_label">label</a>,
1697 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1698 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1699 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1700 <tr>
1701 <td><a href="#t_primitive">primitive</a></td>
1702 <td><a href="#t_label">label</a>,
1703 <a href="#t_void">void</a>,
Tobias Grosser05387292010-12-28 20:29:31 +0000[diff] [blame]1704 <a href="#t_integer">integer</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1705 <a href="#t_floating">floating point</a>,
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1706 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1707 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1708 </tr>
1709 <tr>
1710 <td><a href="#t_derived">derived</a></td>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1711 <td><a href="#t_array">array</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1712 <a href="#t_function">function</a>,
1713 <a href="#t_pointer">pointer</a>,
1714 <a href="#t_struct">structure</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1715 <a href="#t_vector">vector</a>,
1716 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1717 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1718 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1719 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1720</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1721
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1722<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1723 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1724 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1725
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1726</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1727
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1728<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1729<h3>
1730 <a name="t_primitive">Primitive Types</a>
1731</h3>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1732
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1733<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1734
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1735<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1736 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1737
1738<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1739<h4>
1740 <a name="t_integer">Integer Type</a>
1741</h4>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1742
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1743<div>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1744
1745<h5>Overview:</h5>
1746<p>The integer type is a very simple type that simply specifies an arbitrary
1747 bit width for the integer type desired. Any bit width from 1 bit to
1748 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1749
1750<h5>Syntax:</h5>
1751<pre>
1752 iN
1753</pre>
1754
1755<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1756 value.</p>
1757
1758<h5>Examples:</h5>
1759<table class="layout">
1760 <tr class="layout">
1761 <td class="left"><tt>i1</tt></td>
1762 <td class="left">a single-bit integer.</td>
1763 </tr>
1764 <tr class="layout">
1765 <td class="left"><tt>i32</tt></td>
1766 <td class="left">a 32-bit integer.</td>
1767 </tr>
1768 <tr class="layout">
1769 <td class="left"><tt>i1942652</tt></td>
1770 <td class="left">a really big integer of over 1 million bits.</td>
1771 </tr>
1772</table>
1773
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1774</div>
1775
1776<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1777<h4>
1778 <a name="t_floating">Floating Point Types</a>
1779</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1780
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1781<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1782
1783<table>
1784 <tbody>
1785 <tr><th>Type</th><th>Description</th></tr>
1786 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1787 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1788 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1789 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1790 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1791 </tbody>
1792</table>
1793
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1794</div>
1795
1796<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1797<h4>
1798 <a name="t_x86mmx">X86mmx Type</a>
1799</h4>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1800
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1801<div>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1802
1803<h5>Overview:</h5>
1804<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>
1805
1806<h5>Syntax:</h5>
1807<pre>
Dale Johannesen473a8c82010-10-01 01:07:02 +0000[diff] [blame]1808 x86mmx
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1809</pre>
1810
1811</div>
1812
1813<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1814<h4>
1815 <a name="t_void">Void Type</a>
1816</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1817
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1818<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1819
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1820<h5>Overview:</h5>
1821<p>The void type does not represent any value and has no size.</p>
1822
1823<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1824<pre>
1825 void
1826</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1827
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1828</div>
1829
1830<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1831<h4>
1832 <a name="t_label">Label Type</a>
1833</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1834
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1835<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1836
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1837<h5>Overview:</h5>
1838<p>The label type represents code labels.</p>
1839
1840<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1841<pre>
1842 label
1843</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1844
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1845</div>
1846
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1847<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1848<h4>
1849 <a name="t_metadata">Metadata Type</a>
1850</h4>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1851
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1852<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1853
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1854<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1855<p>The metadata type represents embedded metadata. No derived types may be
1856 created from metadata except for <a href="#t_function">function</a>
1857 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1858
1859<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1860<pre>
1861 metadata
1862</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1863
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1864</div>
1865
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1866</div>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1867
1868<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1869<h3>
1870 <a name="t_derived">Derived Types</a>
1871</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1872
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1873<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1874
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1875<p>The real power in LLVM comes from the derived types in the system. This is
1876 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1877 useful types. Each of these types contain one or more element types which
1878 may be a primitive type, or another derived type. For example, it is
1879 possible to have a two dimensional array, using an array as the element type
1880 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1881
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1882</div>
1883
1884
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1885<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1886<h4>
1887 <a name="t_aggregate">Aggregate Types</a>
1888</h4>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1889
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1890<div>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1891
1892<p>Aggregate Types are a subset of derived types that can contain multiple
1893 member types. <a href="#t_array">Arrays</a>,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]1894 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1895 aggregate types.</p>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1896
1897</div>
1898
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1899<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1900<h4>
1901 <a name="t_array">Array Type</a>
1902</h4>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1903
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1904<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1905
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1906<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1907<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1908 sequentially in memory. The array type requires a size (number of elements)
1909 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1910
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1911<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1912<pre>
1913 [&lt;# elements&gt; x &lt;elementtype&gt;]
1914</pre>
1915
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1916<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1917 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1918
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1919<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1920<table class="layout">
1921 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1922 <td class="left"><tt>[40 x i32]</tt></td>
1923 <td class="left">Array of 40 32-bit integer values.</td>
1924 </tr>
1925 <tr class="layout">
1926 <td class="left"><tt>[41 x i32]</tt></td>
1927 <td class="left">Array of 41 32-bit integer values.</td>
1928 </tr>
1929 <tr class="layout">
1930 <td class="left"><tt>[4 x i8]</tt></td>
1931 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1932 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1933</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1934<p>Here are some examples of multidimensional arrays:</p>
1935<table class="layout">
1936 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1937 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1938 <td class="left">3x4 array of 32-bit integer values.</td>
1939 </tr>
1940 <tr class="layout">
1941 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1942 <td class="left">12x10 array of single precision floating point values.</td>
1943 </tr>
1944 <tr class="layout">
1945 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1946 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1947 </tr>
1948</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1949
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1950<p>There is no restriction on indexing beyond the end of the array implied by
1951 a static type (though there are restrictions on indexing beyond the bounds
1952 of an allocated object in some cases). This means that single-dimension
1953 'variable sized array' addressing can be implemented in LLVM with a zero
1954 length array type. An implementation of 'pascal style arrays' in LLVM could
1955 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1956
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1957</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1958
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1959<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1960<h4>
1961 <a name="t_function">Function Type</a>
1962</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1963
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1964<div>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1965
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1966<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1967<p>The function type can be thought of as a function signature. It consists of
1968 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]1969 function type is a first class type or a void type.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1970
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1971<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1972<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1973 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1974</pre>
1975
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1976<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]1977 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1978 which indicates that the function takes a variable number of arguments.
1979 Variable argument functions can access their arguments with
1980 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1981 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1982 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1983
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1984<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1985<table class="layout">
1986 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1987 <td class="left"><tt>i32 (i32)</tt></td>
1988 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1989 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1990 </tr><tr class="layout">
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1991 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1992 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1993 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1994 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1995 returning <tt>float</tt>.
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1996 </td>
1997 </tr><tr class="layout">
1998 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1999 <td class="left">A vararg function that takes at least one
2000 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
2001 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]2002 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2003 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]2004 </tr><tr class="layout">
2005 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]2006 <td class="left">A function taking an <tt>i32</tt>, returning a
2007 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]2008 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2009 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2010</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2011
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2012</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2013
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2014<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2015<h4>
2016 <a name="t_struct">Structure Type</a>
2017</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2018
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2019<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2020
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2021<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2022<p>The structure type is used to represent a collection of data members together
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2023 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]2024
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]2025<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
2026 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
2027 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
2028 Structures in registers are accessed using the
2029 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
2030 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2031
2032<p>Structures may optionally be "packed" structures, which indicate that the
2033 alignment of the struct is one byte, and that there is no padding between
Chris Lattner2c38d652011-08-12 17:31:02 +0000[diff] [blame]2034 the elements. In non-packed structs, padding between field types is inserted
2035 as defined by the TargetData string in the module, which is required to match
2036 what the underlying processor expects.</p>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2037
Chris Lattner2c38d652011-08-12 17:31:02 +0000[diff] [blame]2038<p>Structures can either be "literal" or "identified". A literal structure is
2039 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) whereas identified
2040 types are always defined at the top level with a name. Literal types are
2041 uniqued by their contents and can never be recursive or opaque since there is
Chris Lattneraa175c32011-08-12 18:12:40 +0000[diff] [blame]2042 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]2043 never uniqued.
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2044</p>
2045
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2046<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2047<pre>
Chris Lattner2c38d652011-08-12 17:31:02 +0000[diff] [blame]2048 %T1 = type { &lt;type list&gt; } <i>; Identified normal struct type</i>
2049 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Identified packed struct type</i>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2050</pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2051
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2052<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2053<table class="layout">
2054 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2055 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
2056 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2057 </tr>
2058 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2059 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
2060 <td class="left">A pair, where the first element is a <tt>float</tt> and the
2061 second element is a <a href="#t_pointer">pointer</a> to a
2062 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
2063 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2064 </tr>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2065 <tr class="layout">
2066 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
2067 <td class="left">A packed struct known to be 5 bytes in size.</td>
2068 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2069</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2070
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2071</div>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2072
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2073<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2074<h4>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]2075 <a name="t_opaque">Opaque Structure Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2076</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2077
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2078<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2079
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2080<h5>Overview:</h5>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]2081<p>Opaque structure types are used to represent named structure types that do
2082 not have a body specified. This corresponds (for example) to the C notion of
2083 a forward declared structure.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2084
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2085<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2086<pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2087 %X = type opaque
2088 %52 = type opaque
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2089</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2090
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2091<h5>Examples:</h5>
2092<table class="layout">
2093 <tr class="layout">
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2094 <td class="left"><tt>opaque</tt></td>
2095 <td class="left">An opaque type.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2096 </tr>
2097</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2098
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2099</div>
2100
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2101
2102
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2103<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2104<h4>
2105 <a name="t_pointer">Pointer Type</a>
2106</h4>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2107
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2108<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2109
2110<h5>Overview:</h5>
Dan Gohmanff3ef322010-02-25 16:50:07 +0000[diff] [blame]2111<p>The pointer type is used to specify memory locations.
2112 Pointers are commonly used to reference objects in memory.</p>
2113
2114<p>Pointer types may have an optional address space attribute defining the
2115 numbered address space where the pointed-to object resides. The default
2116 address space is number zero. The semantics of non-zero address
2117 spaces are target-specific.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2118
2119<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
2120 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2121
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2122<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2123<pre>
2124 &lt;type&gt; *
2125</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2126
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2127<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2128<table class="layout">
2129 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2130 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2131 <td class="left">A <a href="#t_pointer">pointer</a> to <a
2132 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
2133 </tr>
2134 <tr class="layout">
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]2135 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2136 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2137 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2138 <tt>i32</tt>.</td>
2139 </tr>
2140 <tr class="layout">
2141 <td class="left"><tt>i32 addrspace(5)*</tt></td>
2142 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
2143 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2144 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2145</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2146
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2147</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2148
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2149<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2150<h4>
2151 <a name="t_vector">Vector Type</a>
2152</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2153
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2154<div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2155
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2156<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2157<p>A vector type is a simple derived type that represents a vector of elements.
2158 Vector types are used when multiple primitive data are operated in parallel
2159 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]2160 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2161 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2162
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2163<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2164<pre>
2165 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2166</pre>
2167
Chris Lattner7d2e7be2010-10-10 18:20:35 +0000[diff] [blame]2168<p>The number of elements is a constant integer value larger than 0; elementtype
2169 may be any integer or floating point type. Vectors of size zero are not
2170 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2171
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2172<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2173<table class="layout">
2174 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2175 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
2176 <td class="left">Vector of 4 32-bit integer values.</td>
2177 </tr>
2178 <tr class="layout">
2179 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
2180 <td class="left">Vector of 8 32-bit floating-point values.</td>
2181 </tr>
2182 <tr class="layout">
2183 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2184 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2185 </tr>
2186</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2187
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2188</div>
2189
Bill Wendlingaf75f0c2011-07-31 06:47:33 +0000[diff] [blame]2190</div>
2191
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2192<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2193<h2><a name="constants">Constants</a></h2>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2194<!-- *********************************************************************** -->
2195
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2196<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2197
2198<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2199 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2200
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2201<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2202<h3>
2203 <a name="simpleconstants">Simple Constants</a>
2204</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2205
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2206<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2207
2208<dl>
2209 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2210 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]2211 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2212
2213 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2214 <dd>Standard integers (such as '4') are constants of
2215 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2216 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2217
2218 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2219 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2220 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2221 notation (see below). The assembler requires the exact decimal value of a
2222 floating-point constant. For example, the assembler accepts 1.25 but
2223 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2224 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2225
2226 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2227 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2228 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2229</dl>
2230
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2231<p>The one non-intuitive notation for constants is the hexadecimal form of
2232 floating point constants. For example, the form '<tt>double
2233 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2234 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2235 constants are required (and the only time that they are generated by the
2236 disassembler) is when a floating point constant must be emitted but it cannot
2237 be represented as a decimal floating point number in a reasonable number of
2238 digits. For example, NaN's, infinities, and other special values are
2239 represented in their IEEE hexadecimal format so that assembly and disassembly
2240 do not cause any bits to change in the constants.</p>
2241
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]2242<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2243 represented using the 16-digit form shown above (which matches the IEEE754
2244 representation for double); float values must, however, be exactly
2245 representable as IEE754 single precision. Hexadecimal format is always used
2246 for long double, and there are three forms of long double. The 80-bit format
2247 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2248 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2249 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2250 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2251 currently supported target uses this format. Long doubles will only work if
2252 they match the long double format on your target. All hexadecimal formats
2253 are big-endian (sign bit at the left).</p>
2254
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]2255<p>There are no constants of type x86mmx.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2256</div>
2257
2258<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2259<h3>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2260<a name="aggregateconstants"></a> <!-- old anchor -->
2261<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2262</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2263
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2264<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2265
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2266<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2267 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2268
2269<dl>
2270 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2271 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2272 type definitions (a comma separated list of elements, surrounded by braces
2273 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2274 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2275 Structure constants must have <a href="#t_struct">structure type</a>, and
2276 the number and types of elements must match those specified by the
2277 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2278
2279 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2280 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2281 definitions (a comma separated list of elements, surrounded by square
2282 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2283 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2284 the number and types of elements must match those specified by the
2285 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2286
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2287 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2288 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2289 definitions (a comma separated list of elements, surrounded by
2290 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2291 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2292 have <a href="#t_vector">vector type</a>, and the number and types of
2293 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2294
2295 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2296 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2297 value to zero of <em>any</em> type, including scalar and
2298 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2299 This is often used to avoid having to print large zero initializers
2300 (e.g. for large arrays) and is always exactly equivalent to using explicit
2301 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2302
2303 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2304 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2305 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2306 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2307 be interpreted as part of the instruction stream, metadata is a place to
2308 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2309</dl>
2310
2311</div>
2312
2313<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2314<h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2315 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2316</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2317
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2318<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2319
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2320<p>The addresses of <a href="#globalvars">global variables</a>
2321 and <a href="#functionstructure">functions</a> are always implicitly valid
2322 (link-time) constants. These constants are explicitly referenced when
2323 the <a href="#identifiers">identifier for the global</a> is used and always
2324 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2325 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2326
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2327<pre class="doc_code">
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2328@X = global i32 17
2329@Y = global i32 42
2330@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2331</pre>
2332
2333</div>
2334
2335<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2336<h3>
2337 <a name="undefvalues">Undefined Values</a>
2338</h3>
2339
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2340<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2341
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2342<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]2343 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2344 Undefined values may be of any type (other than '<tt>label</tt>'
2345 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2346
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2347<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2348 program is well defined no matter what value is used. This gives the
2349 compiler more freedom to optimize. Here are some examples of (potentially
2350 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2351
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2352
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2353<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2354 %A = add %X, undef
2355 %B = sub %X, undef
2356 %C = xor %X, undef
2357Safe:
2358 %A = undef
2359 %B = undef
2360 %C = undef
2361</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2362
2363<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]2364 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]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 = or %X, undef
2368 %B = and %X, undef
2369Safe:
2370 %A = -1
2371 %B = 0
2372Unsafe:
2373 %A = undef
2374 %B = undef
2375</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2376
2377<p>These logical operations have bits that are not always affected by the input.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2378 For example, if <tt>%X</tt> has a zero bit, then the output of the
2379 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2380 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2381 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2382 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2383 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2384 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2385 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2386
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2387<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2388 %A = select undef, %X, %Y
2389 %B = select undef, 42, %Y
2390 %C = select %X, %Y, undef
2391Safe:
2392 %A = %X (or %Y)
2393 %B = 42 (or %Y)
2394 %C = %Y
2395Unsafe:
2396 %A = undef
2397 %B = undef
2398 %C = undef
2399</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2400
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2401<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2402 branch) conditions can go <em>either way</em>, but they have to come from one
2403 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2404 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2405 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2406 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2407 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2408 eliminated.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2409
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2410<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2411 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2412
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2413 %B = undef
2414 %C = xor %B, %B
2415
2416 %D = undef
2417 %E = icmp lt %D, 4
2418 %F = icmp gte %D, 4
2419
2420Safe:
2421 %A = undef
2422 %B = undef
2423 %C = undef
2424 %D = undef
2425 %E = undef
2426 %F = undef
2427</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2428
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2429<p>This example points out that two '<tt>undef</tt>' operands are not
2430 necessarily the same. This can be surprising to people (and also matches C
2431 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2432 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2433 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2434 its value over its "live range". This is true because the variable doesn't
2435 actually <em>have a live range</em>. Instead, the value is logically read
2436 from arbitrary registers that happen to be around when needed, so the value
2437 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2438 need to have the same semantics or the core LLVM "replace all uses with"
2439 concept would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2440
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2441<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2442 %A = fdiv undef, %X
2443 %B = fdiv %X, undef
2444Safe:
2445 %A = undef
2446b: unreachable
2447</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2448
2449<p>These examples show the crucial difference between an <em>undefined
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2450 value</em> and <em>undefined behavior</em>. An undefined value (like
2451 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2452 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2453 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2454 defined on SNaN's. However, in the second example, we can make a more
2455 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2456 arbitrary value, we are allowed to assume that it could be zero. Since a
2457 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2458 the operation does not execute at all. This allows us to delete the divide and
2459 all code after it. Because the undefined operation "can't happen", the
2460 optimizer can assume that it occurs in dead code.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2461
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2462<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2463a: store undef -> %X
2464b: store %X -> undef
2465Safe:
2466a: &lt;deleted&gt;
2467b: unreachable
2468</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2469
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2470<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2471 undefined value can be assumed to not have any effect; we can assume that the
2472 value is overwritten with bits that happen to match what was already there.
2473 However, a store <em>to</em> an undefined location could clobber arbitrary
2474 memory, therefore, it has undefined behavior.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2475
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2476</div>
2477
2478<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2479<h3>
2480 <a name="trapvalues">Trap Values</a>
2481</h3>
2482
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2483<div>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2484
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2485<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2486 instead of representing an unspecified bit pattern, they represent the
2487 fact that an instruction or constant expression which cannot evoke side
2488 effects has nevertheless detected a condition which results in undefined
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2489 behavior.</p>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2490
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2491<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]2492 only exist when produced by operations such as
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2493 <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]2494
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2495<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2496
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2497<ul>
2498<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2499 their operands.</li>
2500
2501<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2502 to their dynamic predecessor basic block.</li>
2503
2504<li>Function arguments depend on the corresponding actual argument values in
2505 the dynamic callers of their functions.</li>
2506
2507<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2508 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2509 control back to them.</li>
2510
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2511<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2512 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2513 or exception-throwing call instructions that dynamically transfer control
2514 back to them.</li>
2515
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2516<li>Non-volatile loads and stores depend on the most recent stores to all of the
2517 referenced memory addresses, following the order in the IR
2518 (including loads and stores implied by intrinsics such as
2519 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2520
Dan Gohman7c24ff12010-05-03 14:59:34 +0000[diff] [blame]2521<!-- TODO: In the case of multiple threads, this only applies if the store
2522 "happens-before" the load or store. -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2523
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2524<!-- TODO: floating-point exception state -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2525
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2526<li>An instruction with externally visible side effects depends on the most
2527 recent preceding instruction with externally visible side effects, following
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]2528 the order in the IR. (This includes
2529 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2530
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2531<li>An instruction <i>control-depends</i> on a
2532 <a href="#terminators">terminator instruction</a>
2533 if the terminator instruction has multiple successors and the instruction
2534 is always executed when control transfers to one of the successors, and
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2535 may not be executed when control is transferred to another.</li>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2536
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2537<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2538 instruction if the set of instructions it otherwise depends on would be
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2539 different if the terminator had transferred control to a different
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2540 successor.</li>
2541
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2542<li>Dependence is transitive.</li>
2543
2544</ul>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2545
2546<p>Whenever a trap value is generated, all values which depend on it evaluate
2547 to trap. If they have side effects, the evoke their side effects as if each
2548 operand with a trap value were undef. If they have externally-visible side
2549 effects, the behavior is undefined.</p>
2550
2551<p>Here are some examples:</p>
Dan Gohmanc30f6e12010-04-26 20:54:53 +0000[diff] [blame]2552
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2553<pre class="doc_code">
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2554entry:
2555 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2556 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2557 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2558 store i32 0, i32* %trap_yet_again ; undefined behavior
2559
2560 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2561 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2562
2563 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2564
2565 %narrowaddr = bitcast i32* @g to i16*
2566 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2567 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2568 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2569
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2570 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2571 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2572
2573true:
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2574 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2575 ; it has undefined behavior.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2576 br label %end
2577
2578end:
2579 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2580 ; Both edges into this PHI are
2581 ; control-dependent on %cmp, so this
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2582 ; always results in a trap value.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2583
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2584 volatile store i32 0, i32* @g ; This would depend on the store in %true
2585 ; if %cmp is true, or the store in %entry
2586 ; otherwise, so this is undefined behavior.
2587
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2588 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2589 ; The same branch again, but this time the
2590 ; true block doesn't have side effects.
2591
2592second_true:
2593 ; No side effects!
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2594 ret void
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2595
2596second_end:
2597 volatile store i32 0, i32* @g ; This time, the instruction always depends
2598 ; on the store in %end. Also, it is
2599 ; control-equivalent to %end, so this is
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2600 ; well-defined (again, ignoring earlier
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2601 ; undefined behavior in this example).
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2602</pre>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2603
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2604</div>
2605
2606<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2607<h3>
2608 <a name="blockaddress">Addresses of Basic Blocks</a>
2609</h3>
2610
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2611<div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2612
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2613<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2614
2615<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2616 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2617 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2618
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2619<p>This value only has defined behavior when used as an operand to the
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2620 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2621 comparisons against null. Pointer equality tests between labels addresses
2622 results in undefined behavior &mdash; though, again, comparison against null
2623 is ok, and no label is equal to the null pointer. This may be passed around
2624 as an opaque pointer sized value as long as the bits are not inspected. This
2625 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2626 long as the original value is reconstituted before the <tt>indirectbr</tt>
2627 instruction.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2628
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2629<p>Finally, some targets may provide defined semantics when using the value as
2630 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2631
2632</div>
2633
2634
2635<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2636<h3>
2637 <a name="constantexprs">Constant Expressions</a>
2638</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2639
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2640<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2641
2642<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2643 to be used as constants. Constant expressions may be of
2644 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2645 operation that does not have side effects (e.g. load and call are not
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2646 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2647
2648<dl>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2649 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2650 <dd>Truncate a constant to another type. The bit size of CST must be larger
2651 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2652
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2653 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2654 <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]2655 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2656
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2657 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2658 <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]2659 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2660
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2661 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2662 <dd>Truncate a floating point constant to another floating point type. The
2663 size of CST must be larger than the size of TYPE. Both types must be
2664 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2665
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2666 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2667 <dd>Floating point extend a constant to another type. The size of CST must be
2668 smaller or equal to the size of TYPE. Both types must be floating
2669 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2670
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2671 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2672 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2673 constant. TYPE must be a scalar or vector integer type. CST must be of
2674 scalar or vector floating point type. Both CST and TYPE must be scalars,
2675 or vectors of the same number of elements. If the value won't fit in the
2676 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2677
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2678 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2679 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2680 constant. TYPE must be a scalar or vector integer type. CST must be of
2681 scalar or vector floating point type. Both CST and TYPE must be scalars,
2682 or vectors of the same number of elements. If the value won't fit in the
2683 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2684
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2685 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2686 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2687 constant. TYPE must be a scalar or vector floating point type. CST must be
2688 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2689 vectors of the same number of elements. If the value won't fit in the
2690 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2691
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2692 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2693 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2694 constant. TYPE must be a scalar or vector floating point type. CST must be
2695 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2696 vectors of the same number of elements. If the value won't fit in the
2697 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2698
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2699 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2700 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2701 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2702 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2703 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2704
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2705 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2706 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2707 type. CST must be of integer type. The CST value is zero extended,
2708 truncated, or unchanged to make it fit in a pointer size. This one is
2709 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2710
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2711 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2712 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2713 are the same as those for the <a href="#i_bitcast">bitcast
2714 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2715
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2716 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2717 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2718 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2719 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2720 instruction, the index list may have zero or more indexes, which are
2721 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2722
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2723 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2724 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2725
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2726 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2727 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2728
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2729 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2730 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2731
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2732 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2733 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2734 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2735
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2736 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2737 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2738 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2739
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2740 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2741 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2742 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2743
Nick Lewycky9e130ce2010-05-29 06:44:15 +0000[diff] [blame]2744 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2745 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2746 constants. The index list is interpreted in a similar manner as indices in
2747 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2748 index value must be specified.</dd>
2749
2750 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2751 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2752 constants. The index list is interpreted in a similar manner as indices in
2753 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2754 index value must be specified.</dd>
2755
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2756 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2757 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2758 be any of the <a href="#binaryops">binary</a>
2759 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2760 on operands are the same as those for the corresponding instruction
2761 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2762</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2763
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2764</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2765
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2766</div>
2767
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2768<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2769<h2><a name="othervalues">Other Values</a></h2>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2770<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2771<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2772<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2773<h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2774<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2775</h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2776
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2777<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2778
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2779<p>LLVM supports inline assembler expressions (as opposed
2780 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2781 a special value. This value represents the inline assembler as a string
2782 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2783 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2784 expression has side effects, and a flag indicating whether the function
2785 containing the asm needs to align its stack conservatively. An example
2786 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2787
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2788<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2789i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2790</pre>
2791
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2792<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2793 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2794 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2795
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2796<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2797%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]2798</pre>
2799
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2800<p>Inline asms with side effects not visible in the constraint list must be
2801 marked as having side effects. This is done through the use of the
2802 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2803
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2804<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2805call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2806</pre>
2807
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2808<p>In some cases inline asms will contain code that will not work unless the
2809 stack is aligned in some way, such as calls or SSE instructions on x86,
2810 yet will not contain code that does that alignment within the asm.
2811 The compiler should make conservative assumptions about what the asm might
2812 contain and should generate its usual stack alignment code in the prologue
2813 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2814
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2815<pre class="doc_code">
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2816call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2817</pre>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2818
2819<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2820 first.</p>
2821
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2822<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2823 documented here. Constraints on what can be done (e.g. duplication, moving,
2824 etc need to be documented). This is probably best done by reference to
2825 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2826
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2827<h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2828<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2829</h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2830
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2831<div>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2832
2833<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2834 attached to it that contains a list of constant integers. If present, the
2835 code generator will use the integer as the location cookie value when report
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2836 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]2837 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2838 source code that produced it. For example:</p>
2839
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2840<pre class="doc_code">
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2841call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2842...
2843!42 = !{ i32 1234567 }
2844</pre>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2845
2846<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]2847 IR. If the MDNode contains multiple constants, the code generator will use
2848 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]2849
2850</div>
2851
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2852</div>
2853
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2854<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2855<h3>
2856 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2857</h3>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2858
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2859<div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2860
2861<p>LLVM IR allows metadata to be attached to instructions in the program that
2862 can convey extra information about the code to the optimizers and code
2863 generator. One example application of metadata is source-level debug
2864 information. There are two metadata primitives: strings and nodes. All
2865 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2866 preceding exclamation point ('<tt>!</tt>').</p>
2867
2868<p>A metadata string is a string surrounded by double quotes. It can contain
2869 any character by escaping non-printable characters with "\xx" where "xx" is
2870 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2871
2872<p>Metadata nodes are represented with notation similar to structure constants
2873 (a comma separated list of elements, surrounded by braces and preceded by an
2874 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2875 10}</tt>". Metadata nodes can have any values as their operand.</p>
2876
2877<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2878 metadata nodes, which can be looked up in the module symbol table. For
2879 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2880
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2881<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2882 function is using two metadata arguments.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2883
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2884<div class="doc_code">
2885<pre>
2886call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2887</pre>
2888</div>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2889
2890<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2891 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2892
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2893<div class="doc_code">
2894<pre>
2895%indvar.next = add i64 %indvar, 1, !dbg !21
2896</pre>
2897</div>
2898
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2899</div>
2900
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2901</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2902
2903<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2904<h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2905 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2906</h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2907<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2908<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2909<p>LLVM has a number of "magic" global variables that contain data that affect
2910code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2911of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2912section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2913by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2914
2915<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2916<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2917<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2918</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2919
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2920<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2921
2922<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2923href="#linkage_appending">appending linkage</a>. This array contains a list of
2924pointers to global variables and functions which may optionally have a pointer
2925cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2926
2927<pre>
2928 @X = global i8 4
2929 @Y = global i32 123
2930
2931 @llvm.used = appending global [2 x i8*] [
2932 i8* @X,
2933 i8* bitcast (i32* @Y to i8*)
2934 ], section "llvm.metadata"
2935</pre>
2936
2937<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2938compiler, assembler, and linker are required to treat the symbol as if there is
2939a reference to the global that it cannot see. For example, if a variable has
2940internal linkage and no references other than that from the <tt>@llvm.used</tt>
2941list, it cannot be deleted. This is commonly used to represent references from
2942inline asms and other things the compiler cannot "see", and corresponds to
2943"attribute((used))" in GNU C.</p>
2944
2945<p>On some targets, the code generator must emit a directive to the assembler or
2946object file to prevent the assembler and linker from molesting the symbol.</p>
2947
2948</div>
2949
2950<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2951<h3>
2952 <a name="intg_compiler_used">
2953 The '<tt>llvm.compiler.used</tt>' Global Variable
2954 </a>
2955</h3>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2956
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2957<div>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2958
2959<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2960<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2961touching the symbol. On targets that support it, this allows an intelligent
2962linker to optimize references to the symbol without being impeded as it would be
2963by <tt>@llvm.used</tt>.</p>
2964
2965<p>This is a rare construct that should only be used in rare circumstances, and
2966should not be exposed to source languages.</p>
2967
2968</div>
2969
2970<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2971<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2972<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2973</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2974
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2975<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2976<pre>
2977%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2978@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2979</pre>
2980<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.
2981</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2982
2983</div>
2984
2985<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2986<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2987<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2988</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2989
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2990<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2991<pre>
2992%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2993@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2994</pre>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2995
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2996<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.
2997</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2998
2999</div>
3000
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3001</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3002
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]3003<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3004<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3005<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3006
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3007<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3008
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3009<p>The LLVM instruction set consists of several different classifications of
3010 instructions: <a href="#terminators">terminator
3011 instructions</a>, <a href="#binaryops">binary instructions</a>,
3012 <a href="#bitwiseops">bitwise binary instructions</a>,
3013 <a href="#memoryops">memory instructions</a>, and
3014 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3015
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3016<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3017<h3>
3018 <a name="terminators">Terminator Instructions</a>
3019</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3020
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3021<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3022
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3023<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
3024 in a program ends with a "Terminator" instruction, which indicates which
3025 block should be executed after the current block is finished. These
3026 terminator instructions typically yield a '<tt>void</tt>' value: they produce
3027 control flow, not values (the one exception being the
3028 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
3029
Chris Lattner6445ecb2011-08-02 20:29:13 +0000[diff] [blame]3030<p>The terminator instructions are:
3031 '<a href="#i_ret"><tt>ret</tt></a>',
3032 '<a href="#i_br"><tt>br</tt></a>',
3033 '<a href="#i_switch"><tt>switch</tt></a>',
3034 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>',
3035 '<a href="#i_invoke"><tt>invoke</tt></a>',
3036 '<a href="#i_unwind"><tt>unwind</tt></a>',
3037 '<a href="#i_resume"><tt>resume</tt></a>', and
3038 '<a href="#i_unreachable"><tt>unreachable</tt></a>'.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3039
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3040<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3041<h4>
3042 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
3043</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3044
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3045<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3046
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3047<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]3048<pre>
3049 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]3050 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3051</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3052
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3053<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3054<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
3055 a value) from a function back to the caller.</p>
3056
3057<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
3058 value and then causes control flow, and one that just causes control flow to
3059 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3060
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3061<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3062<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
3063 return value. The type of the return value must be a
3064 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]3065
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3066<p>A function is not <a href="#wellformed">well formed</a> if it it has a
3067 non-void return type and contains a '<tt>ret</tt>' instruction with no return
3068 value or a return value with a type that does not match its type, or if it
3069 has a void return type and contains a '<tt>ret</tt>' instruction with a
3070 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3071
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3072<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3073<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
3074 the calling function's context. If the caller is a
3075 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
3076 instruction after the call. If the caller was an
3077 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
3078 the beginning of the "normal" destination block. If the instruction returns
3079 a value, that value shall set the call or invoke instruction's return
3080 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3081
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3082<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3083<pre>
3084 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3085 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]3086 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]3087</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3088
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3089</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3090<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3091<h4>
3092 <a name="i_br">'<tt>br</tt>' Instruction</a>
3093</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3094
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3095<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3096
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3097<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3098<pre>
Bill Wendlingb3aa4712011-07-26 10:41:15 +0000[diff] [blame]3099 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;
3100 br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3101</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3102
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3103<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3104<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3105 different basic block in the current function. There are two forms of this
3106 instruction, corresponding to a conditional branch and an unconditional
3107 branch.</p>
3108
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3109<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3110<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3111 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3112 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3113 target.</p>
3114
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3115<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3116<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3117 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3118 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3119 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3120
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3121<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]3122<pre>
3123Test:
3124 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3125 br i1 %cond, label %IfEqual, label %IfUnequal
3126IfEqual:
3127 <a href="#i_ret">ret</a> i32 1
3128IfUnequal:
3129 <a href="#i_ret">ret</a> i32 0
3130</pre>
3131
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3132</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3133
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3134<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3135<h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3136 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3137</h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3138
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3139<div>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3140
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3141<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3142<pre>
3143 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3144</pre>
3145
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3146<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3147<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]3148 several different places. It is a generalization of the '<tt>br</tt>'
3149 instruction, allowing a branch to occur to one of many possible
3150 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3151
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3152<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3153<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3154 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3155 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3156 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3157
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3158<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3159<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3160 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3161 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]3162 transferred to the corresponding destination; otherwise, control flow is
3163 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3164
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3165<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3166<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3167 <tt>switch</tt> instruction, this instruction may be code generated in
3168 different ways. For example, it could be generated as a series of chained
3169 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3170
3171<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3172<pre>
3173 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3174 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3175 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3176
3177 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3178 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3179
3180 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3181 switch i32 %val, label %otherwise [ i32 0, label %onzero
3182 i32 1, label %onone
3183 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3184</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3185
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3186</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3187
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3188
3189<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3190<h4>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3191 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3192</h4>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3193
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3194<div>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3195
3196<h5>Syntax:</h5>
3197<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3198 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]3199</pre>
3200
3201<h5>Overview:</h5>
3202
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3203<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3204 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]3205 "<tt>address</tt>". Address must be derived from a <a
3206 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3207
3208<h5>Arguments:</h5>
3209
3210<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3211 rest of the arguments indicate the full set of possible destinations that the
3212 address may point to. Blocks are allowed to occur multiple times in the
3213 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3214
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3215<p>This destination list is required so that dataflow analysis has an accurate
3216 understanding of the CFG.</p>
3217
3218<h5>Semantics:</h5>
3219
3220<p>Control transfers to the block specified in the address argument. All
3221 possible destination blocks must be listed in the label list, otherwise this
3222 instruction has undefined behavior. This implies that jumps to labels
3223 defined in other functions have undefined behavior as well.</p>
3224
3225<h5>Implementation:</h5>
3226
3227<p>This is typically implemented with a jump through a register.</p>
3228
3229<h5>Example:</h5>
3230<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3231 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3232</pre>
3233
3234</div>
3235
3236
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3237<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3238<h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3239 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3240</h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3241
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3242<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3243
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3244<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3245<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3246 &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]3247 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3248</pre>
3249
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3250<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3251<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3252 function, with the possibility of control flow transfer to either the
3253 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3254 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3255 control flow will return to the "normal" label. If the callee (or any
3256 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3257 instruction, control is interrupted and continued at the dynamically nearest
3258 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3259
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3260<p>The '<tt>exception</tt>' label is a
3261 <i><a href="ExceptionHandling.html#overview">landing pad</a></i> for the
3262 exception. As such, '<tt>exception</tt>' label is required to have the
3263 "<a href="#i_landingpad"><tt>landingpad</tt></a>" instruction, which contains
3264 the information about about the behavior of the program after unwinding
3265 happens, as its first non-PHI instruction. The restrictions on the
3266 "<tt>landingpad</tt>" instruction's tightly couples it to the
3267 "<tt>invoke</tt>" instruction, so that the important information contained
3268 within the "<tt>landingpad</tt>" instruction can't be lost through normal
3269 code motion.</p>
3270
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3271<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3272<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3273
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3274<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3275 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3276 convention</a> the call should use. If none is specified, the call
3277 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3278
3279 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3280 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3281 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3282
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3283 <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]3284 function value being invoked. In most cases, this is a direct function
3285 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3286 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3287
3288 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3289 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3290
3291 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]3292 signature argument types and parameter attributes. All arguments must be
3293 of <a href="#t_firstclass">first class</a> type. If the function
3294 signature indicates the function accepts a variable number of arguments,
3295 the extra arguments can be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3296
3297 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3298 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3299
3300 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3301 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3302
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3303 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3304 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3305 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3306</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3307
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3308<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3309<p>This instruction is designed to operate as a standard
3310 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3311 primary difference is that it establishes an association with a label, which
3312 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3313
3314<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3315 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3316 exception. Additionally, this is important for implementation of
3317 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3318
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3319<p>For the purposes of the SSA form, the definition of the value returned by the
3320 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3321 block to the "normal" label. If the callee unwinds then no return value is
3322 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]3323
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3324<p>Note that the code generator does not yet completely support unwind, and
3325that the invoke/unwind semantics are likely to change in future versions.</p>
3326
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3327<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3328<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3329 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3330 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3331 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3332 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3333</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3334
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3335</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3336
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3337<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3338
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3339<h4>
3340 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3341</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3342
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3343<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3344
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3345<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3346<pre>
3347 unwind
3348</pre>
3349
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3350<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3351<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3352 at the first callee in the dynamic call stack which used
3353 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3354 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3355
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3356<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3357<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3358 immediately halt. The dynamic call stack is then searched for the
3359 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3360 Once found, execution continues at the "exceptional" destination block
3361 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3362 instruction in the dynamic call chain, undefined behavior results.</p>
3363
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3364<p>Note that the code generator does not yet completely support unwind, and
3365that the invoke/unwind semantics are likely to change in future versions.</p>
3366
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3367</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3368
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3369 <!-- _______________________________________________________________________ -->
3370
3371<h4>
3372 <a name="i_resume">'<tt>resume</tt>' Instruction</a>
3373</h4>
3374
3375<div>
3376
3377<h5>Syntax:</h5>
3378<pre>
3379 resume &lt;type&gt; &lt;value&gt;
3380</pre>
3381
3382<h5>Overview:</h5>
3383<p>The '<tt>resume</tt>' instruction is a terminator instruction that has no
3384 successors.</p>
3385
3386<h5>Arguments:</h5>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3387<p>The '<tt>resume</tt>' instruction requires one argument, which must have the
Bill Wendlinge4ad50b2011-08-03 18:37:32 +0000[diff] [blame]3388 same type as the result of any '<tt>landingpad</tt>' instruction in the same
3389 function.</p>
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3390
3391<h5>Semantics:</h5>
3392<p>The '<tt>resume</tt>' instruction resumes propagation of an existing
3393 (in-flight) exception whose unwinding was interrupted with
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3394 a <a href="#i_landingpad"><tt>landingpad</tt></a> instruction.</p>
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3395
3396<h5>Example:</h5>
3397<pre>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]3398 resume { i8*, i32 } %exn
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3399</pre>
3400
3401</div>
3402
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3403<!-- _______________________________________________________________________ -->
3404
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3405<h4>
3406 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3407</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3408
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3409<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3410
3411<h5>Syntax:</h5>
3412<pre>
3413 unreachable
3414</pre>
3415
3416<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3417<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3418 instruction is used to inform the optimizer that a particular portion of the
3419 code is not reachable. This can be used to indicate that the code after a
3420 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3421
3422<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3423<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3424
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3425</div>
3426
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3427</div>
3428
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3429<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3430<h3>
3431 <a name="binaryops">Binary Operations</a>
3432</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3433
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3434<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3435
3436<p>Binary operators are used to do most of the computation in a program. They
3437 require two operands of the same type, execute an operation on them, and
3438 produce a single value. The operands might represent multiple data, as is
3439 the case with the <a href="#t_vector">vector</a> data type. The result value
3440 has the same type as its operands.</p>
3441
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3442<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3443
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3444<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3445<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3446 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3447</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3448
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3449<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3450
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3451<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3452<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3453 &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]3454 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3455 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3456 &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]3457</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3458
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3459<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3460<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3461
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3462<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3463<p>The two arguments to the '<tt>add</tt>' instruction must
3464 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3465 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3466
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3467<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3468<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3469
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3470<p>If the sum has unsigned overflow, the result returned is the mathematical
3471 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]3472
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3473<p>Because LLVM integers use a two's complement representation, this instruction
3474 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3475
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3476<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3477 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3478 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3479 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3480 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3481
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3482<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3483<pre>
3484 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3485</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3486
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3487</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3488
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3489<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3490<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3491 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3492</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3493
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3494<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3495
3496<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3497<pre>
3498 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3499</pre>
3500
3501<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3502<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3503
3504<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3505<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3506 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3507 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3508
3509<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3510<p>The value produced is the floating point sum of the two operands.</p>
3511
3512<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3513<pre>
3514 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3515</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3516
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3517</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3518
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3519<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3520<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3521 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3522</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3523
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3524<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3525
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3526<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3527<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3528 &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]3529 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3530 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3531 &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]3532</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3533
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3534<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3535<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3536 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3537
3538<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3539 '<tt>neg</tt>' instruction present in most other intermediate
3540 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3541
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3542<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3543<p>The two arguments to the '<tt>sub</tt>' instruction must
3544 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3545 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3546
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3547<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3548<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3549
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3550<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3551 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3552 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3553
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3554<p>Because LLVM integers use a two's complement representation, this instruction
3555 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3556
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3557<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3558 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3559 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3560 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3561 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3562
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3563<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3564<pre>
3565 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3566 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3567</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3568
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3569</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3570
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3571<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3572<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3573 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3574</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3575
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3576<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3577
3578<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3579<pre>
3580 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3581</pre>
3582
3583<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3584<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3585 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3586
3587<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3588 '<tt>fneg</tt>' instruction present in most other intermediate
3589 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3590
3591<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3592<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3593 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3594 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3595
3596<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3597<p>The value produced is the floating point difference of the two operands.</p>
3598
3599<h5>Example:</h5>
3600<pre>
3601 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3602 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3603</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3604
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3605</div>
3606
3607<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3608<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3609 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3610</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3611
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3612<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3613
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3614<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3615<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3616 &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]3617 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3618 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3619 &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]3620</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3621
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3622<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3623<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3624
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3625<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3626<p>The two arguments to the '<tt>mul</tt>' instruction must
3627 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3628 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3629
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3630<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3631<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3632
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3633<p>If the result of the multiplication has unsigned overflow, the result
3634 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3635 width of the result.</p>
3636
3637<p>Because LLVM integers use a two's complement representation, and the result
3638 is the same width as the operands, this instruction returns the correct
3639 result for both signed and unsigned integers. If a full product
3640 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3641 be sign-extended or zero-extended as appropriate to the width of the full
3642 product.</p>
3643
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3644<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3645 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3646 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3647 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3648 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3649
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3650<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3651<pre>
3652 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3653</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3654
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3655</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3656
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3657<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3658<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3659 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3660</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3661
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3662<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3663
3664<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3665<pre>
3666 &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]3667</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3668
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3669<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3670<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3671
3672<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3673<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3674 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3675 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3676
3677<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3678<p>The value produced is the floating point product of the two operands.</p>
3679
3680<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3681<pre>
3682 &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]3683</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3684
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3685</div>
3686
3687<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3688<h4>
3689 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3690</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3691
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3692<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3693
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3694<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3695<pre>
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3696 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3697 &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]3698</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3699
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3700<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3701<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3702
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3703<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3704<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3705 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3706 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3707
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3708<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3709<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3710
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3711<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3712 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3713
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3714<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3715
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3716<p>If the <tt>exact</tt> keyword is present, the result value of the
3717 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3718 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3719
3720
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3721<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3722<pre>
3723 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3724</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3725
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3726</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3727
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3728<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3729<h4>
3730 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3731</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3732
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3733<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3734
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3735<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3736<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3737 &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]3738 &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]3739</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3740
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3741<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3742<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3743
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3744<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3745<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3746 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3747 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3748
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3749<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3750<p>The value produced is the signed integer quotient of the two operands rounded
3751 towards zero.</p>
3752
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3753<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3754 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3755
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3756<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3757 undefined behavior; this is a rare case, but can occur, for example, by doing
3758 a 32-bit division of -2147483648 by -1.</p>
3759
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3760<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]3761 <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]3762 be rounded.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3763
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3764<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3765<pre>
3766 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3767</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3768
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3769</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3770
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3771<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3772<h4>
3773 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3774</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3775
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3776<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3777
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3778<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3779<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3780 &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]3781</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3782
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3783<h5>Overview:</h5>
3784<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3785
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3786<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3787<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3788 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3789 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3790
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3791<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3792<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3793
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3794<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3795<pre>
3796 &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]3797</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3798
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3799</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3800
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3801<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3802<h4>
3803 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3804</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3805
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3806<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3807
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3808<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3809<pre>
3810 &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]3811</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3812
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3813<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3814<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3815 division of its two arguments.</p>
3816
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3817<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3818<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3819 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3820 values. Both arguments must have identical types.</p>
3821
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3822<h5>Semantics:</h5>
3823<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3824 This instruction always performs an unsigned division to get the
3825 remainder.</p>
3826
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3827<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3828 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3829
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3830<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3831
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3832<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3833<pre>
3834 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3835</pre>
3836
3837</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3838
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3839<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3840<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3841 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3842</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3843
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3844<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3845
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3846<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3847<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3848 &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]3849</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3850
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3851<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3852<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3853 division of its two operands. This instruction can also take
3854 <a href="#t_vector">vector</a> versions of the values in which case the
3855 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3856
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3857<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3858<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3859 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3860 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3861
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3862<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3863<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sandsdea3a5e2011-03-07 09:12:24 +0000[diff] [blame]3864 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3865 <i>modulo</i> operator (where the result is either zero or has the same sign
3866 as the divisor, <tt>op2</tt>) of a value.
3867 For more information about the difference,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3868 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3869 Math Forum</a>. For a table of how this is implemented in various languages,
3870 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3871 Wikipedia: modulo operation</a>.</p>
3872
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3873<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3874 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3875
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3876<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3877 Overflow also leads to undefined behavior; this is a rare case, but can
3878 occur, for example, by taking the remainder of a 32-bit division of
3879 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3880 lets srem be implemented using instructions that return both the result of
3881 the division and the remainder.)</p>
3882
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3883<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3884<pre>
3885 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3886</pre>
3887
3888</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3889
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3890<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3891<h4>
3892 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3893</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3894
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3895<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3896
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3897<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3898<pre>
3899 &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]3900</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3901
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3902<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3903<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3904 its two operands.</p>
3905
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3906<h5>Arguments:</h5>
3907<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3908 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3909 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3910
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3911<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3912<p>This instruction returns the <i>remainder</i> of a division. The remainder
3913 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3914
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3915<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3916<pre>
3917 &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]3918</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3919
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3920</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3921
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3922</div>
3923
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3924<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3925<h3>
3926 <a name="bitwiseops">Bitwise Binary Operations</a>
3927</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3928
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3929<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3930
3931<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3932 program. They are generally very efficient instructions and can commonly be
3933 strength reduced from other instructions. They require two operands of the
3934 same type, execute an operation on them, and produce a single value. The
3935 resulting value is the same type as its operands.</p>
3936
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3937<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3938<h4>
3939 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3940</h4>
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
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3944<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3945<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3946 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3947 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3948 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3949 &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]3950</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3951
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3952<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3953<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3954 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3955
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3956<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3957<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3958 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3959 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3960
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3961<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3962<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3963 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3964 is (statically or dynamically) negative or equal to or larger than the number
3965 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3966 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3967 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3968
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3969<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3970 <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]3971 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3972 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3973 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3974 they would if the shift were expressed as a mul instruction with the same
3975 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3976
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3977<h5>Example:</h5>
3978<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3979 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3980 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3981 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3982 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3983 &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]3984</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3985
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3986</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3987
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3988<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3989<h4>
3990 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3991</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3992
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3993<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3994
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3995<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3996<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3997 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3998 &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]3999</pre>
4000
4001<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4002<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
4003 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4004
4005<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4006<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4007 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4008 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4009
4010<h5>Semantics:</h5>
4011<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4012 significant bits of the result will be filled with zero bits after the shift.
4013 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
4014 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
4015 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
4016 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4017
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4018<p>If the <tt>exact</tt> keyword is present, the result value of the
4019 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4020 shifted out are non-zero.</p>
4021
4022
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4023<h5>Example:</h5>
4024<pre>
4025 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
4026 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
4027 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
4028 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4029 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]4030 &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]4031</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4032
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4033</div>
4034
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]4035<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4036<h4>
4037 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
4038</h4>
4039
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4040<div>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4041
4042<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4043<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4044 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4045 &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]4046</pre>
4047
4048<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4049<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
4050 operand shifted to the right a specified number of bits with sign
4051 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4052
4053<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4054<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4055 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4056 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4057
4058<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4059<p>This instruction always performs an arithmetic shift right operation, The
4060 most significant bits of the result will be filled with the sign bit
4061 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
4062 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
4063 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
4064 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4065
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4066<p>If the <tt>exact</tt> keyword is present, the result value of the
4067 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4068 shifted out are non-zero.</p>
4069
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4070<h5>Example:</h5>
4071<pre>
4072 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
4073 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
4074 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
4075 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4076 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]4077 &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]4078</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4079
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4080</div>
4081
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4082<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4083<h4>
4084 <a name="i_and">'<tt>and</tt>' Instruction</a>
4085</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4086
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4087<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4088
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4089<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4090<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4091 &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]4092</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4093
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4094<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4095<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
4096 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4097
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4098<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4099<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4100 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4101 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4102
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4103<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4104<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4105
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4106<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4107 <tbody>
4108 <tr>
4109 <td>In0</td>
4110 <td>In1</td>
4111 <td>Out</td>
4112 </tr>
4113 <tr>
4114 <td>0</td>
4115 <td>0</td>
4116 <td>0</td>
4117 </tr>
4118 <tr>
4119 <td>0</td>
4120 <td>1</td>
4121 <td>0</td>
4122 </tr>
4123 <tr>
4124 <td>1</td>
4125 <td>0</td>
4126 <td>0</td>
4127 </tr>
4128 <tr>
4129 <td>1</td>
4130 <td>1</td>
4131 <td>1</td>
4132 </tr>
4133 </tbody>
4134</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4135
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4136<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4137<pre>
4138 &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]4139 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
4140 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4141</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4142</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4143<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4144<h4>
4145 <a name="i_or">'<tt>or</tt>' Instruction</a>
4146</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4147
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4148<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4149
4150<h5>Syntax:</h5>
4151<pre>
4152 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4153</pre>
4154
4155<h5>Overview:</h5>
4156<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4157 two operands.</p>
4158
4159<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4160<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4161 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4162 values. Both arguments must have identical types.</p>
4163
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4164<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4165<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4166
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4167<table border="1" cellspacing="0" cellpadding="4">
4168 <tbody>
4169 <tr>
4170 <td>In0</td>
4171 <td>In1</td>
4172 <td>Out</td>
4173 </tr>
4174 <tr>
4175 <td>0</td>
4176 <td>0</td>
4177 <td>0</td>
4178 </tr>
4179 <tr>
4180 <td>0</td>
4181 <td>1</td>
4182 <td>1</td>
4183 </tr>
4184 <tr>
4185 <td>1</td>
4186 <td>0</td>
4187 <td>1</td>
4188 </tr>
4189 <tr>
4190 <td>1</td>
4191 <td>1</td>
4192 <td>1</td>
4193 </tr>
4194 </tbody>
4195</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4196
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4197<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4198<pre>
4199 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4200 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4201 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4202</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4203
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4204</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4205
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4206<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4207<h4>
4208 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4209</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4210
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4211<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4212
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4213<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4214<pre>
4215 &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]4216</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4217
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4218<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4219<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4220 its two operands. The <tt>xor</tt> is used to implement the "one's
4221 complement" operation, which is the "~" operator in C.</p>
4222
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4223<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4224<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4225 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4226 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4227
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4228<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4229<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4230
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4231<table border="1" cellspacing="0" cellpadding="4">
4232 <tbody>
4233 <tr>
4234 <td>In0</td>
4235 <td>In1</td>
4236 <td>Out</td>
4237 </tr>
4238 <tr>
4239 <td>0</td>
4240 <td>0</td>
4241 <td>0</td>
4242 </tr>
4243 <tr>
4244 <td>0</td>
4245 <td>1</td>
4246 <td>1</td>
4247 </tr>
4248 <tr>
4249 <td>1</td>
4250 <td>0</td>
4251 <td>1</td>
4252 </tr>
4253 <tr>
4254 <td>1</td>
4255 <td>1</td>
4256 <td>0</td>
4257 </tr>
4258 </tbody>
4259</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4260
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4261<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4262<pre>
4263 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4264 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4265 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4266 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4267</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4268
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4269</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4270
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4271</div>
4272
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4273<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4274<h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4275 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4276</h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4277
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4278<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4279
4280<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4281 target-independent manner. These instructions cover the element-access and
4282 vector-specific operations needed to process vectors effectively. While LLVM
4283 does directly support these vector operations, many sophisticated algorithms
4284 will want to use target-specific intrinsics to take full advantage of a
4285 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4286
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4287<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4288<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4289 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4290</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4291
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4292<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4293
4294<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4295<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4296 &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]4297</pre>
4298
4299<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4300<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4301 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4302
4303
4304<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4305<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4306 of <a href="#t_vector">vector</a> type. The second operand is an index
4307 indicating the position from which to extract the element. The index may be
4308 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4309
4310<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4311<p>The result is a scalar of the same type as the element type of
4312 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4313 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4314 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4315
4316<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4317<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4318 &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]4319</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4320
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4321</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4322
4323<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4324<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4325 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4326</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4327
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4328<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4329
4330<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4331<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]4332 &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]4333</pre>
4334
4335<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4336<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4337 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4338
4339<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4340<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4341 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4342 whose type must equal the element type of the first operand. The third
4343 operand is an index indicating the position at which to insert the value.
4344 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4345
4346<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4347<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4348 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4349 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4350 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4351
4352<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4353<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4354 &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]4355</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4356
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4357</div>
4358
4359<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4360<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4361 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4362</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4363
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4364<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4365
4366<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4367<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4368 &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]4369</pre>
4370
4371<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4372<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4373 from two input vectors, returning a vector with the same element type as the
4374 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4375
4376<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4377<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4378 with types that match each other. The third argument is a shuffle mask whose
4379 element type is always 'i32'. The result of the instruction is a vector
4380 whose length is the same as the shuffle mask and whose element type is the
4381 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4382
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4383<p>The shuffle mask operand is required to be a constant vector with either
4384 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4385
4386<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4387<p>The elements of the two input vectors are numbered from left to right across
4388 both of the vectors. The shuffle mask operand specifies, for each element of
4389 the result vector, which element of the two input vectors the result element
4390 gets. The element selector may be undef (meaning "don't care") and the
4391 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4392
4393<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4394<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4395 &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]4396 &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]4397 &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]4398 &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]4399 &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]4400 &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]4401 &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]4402 &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]4403</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4404
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4405</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]4406
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4407</div>
4408
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4409<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4410<h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4411 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4412</h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4413
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4414<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4415
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4416<p>LLVM supports several instructions for working with
4417 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4418
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4419<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4420<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4421 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4422</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4423
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4424<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4425
4426<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4427<pre>
4428 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4429</pre>
4430
4431<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4432<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4433 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4434
4435<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4436<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4437 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4438 <a href="#t_array">array</a> type. The operands are constant indices to
4439 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4440 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4441 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4442 <ul>
4443 <li>Since the value being indexed is not a pointer, the first index is
4444 omitted and assumed to be zero.</li>
4445 <li>At least one index must be specified.</li>
4446 <li>Not only struct indices but also array indices must be in
4447 bounds.</li>
4448 </ul>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4449
4450<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4451<p>The result is the value at the position in the aggregate specified by the
4452 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4453
4454<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4455<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4456 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4457</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4458
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4459</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4460
4461<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4462<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4463 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4464</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4465
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4466<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4467
4468<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4469<pre>
Bill Wendling194229e2011-07-26 20:42:28 +0000[diff] [blame]4470 &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]4471</pre>
4472
4473<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4474<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4475 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4476
4477<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4478<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4479 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4480 <a href="#t_array">array</a> type. The second operand is a first-class
4481 value to insert. The following operands are constant indices indicating
4482 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]4483 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4484 value to insert must have the same type as the value identified by the
4485 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4486
4487<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4488<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4489 that of <tt>val</tt> except that the value at the position specified by the
4490 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4491
4492<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4493<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame]4494 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4495 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4496 %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]4497</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4498
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4499</div>
4500
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4501</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4502
4503<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4504<h3>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4505 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4506</h3>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4507
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4508<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4509
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4510<p>A key design point of an SSA-based representation is how it represents
4511 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4512 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4513 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4514
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4515<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4516<h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4517 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4518</h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4519
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4520<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4521
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4522<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4523<pre>
Dan Gohmanf75a7d32010-05-28 01:14:11 +0000[diff] [blame]4524 &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]4525</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4526
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4527<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4528<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4529 currently executing function, to be automatically released when this function
4530 returns to its caller. The object is always allocated in the generic address
4531 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4532
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4533<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4534<p>The '<tt>alloca</tt>' instruction
4535 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4536 runtime stack, returning a pointer of the appropriate type to the program.
4537 If "NumElements" is specified, it is the number of elements allocated,
4538 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4539 specified, the value result of the allocation is guaranteed to be aligned to
4540 at least that boundary. If not specified, or if zero, the target can choose
4541 to align the allocation on any convenient boundary compatible with the
4542 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4543
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4544<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4545
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4546<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4547<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4548 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4549 memory is automatically released when the function returns. The
4550 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4551 variables that must have an address available. When the function returns
4552 (either with the <tt><a href="#i_ret">ret</a></tt>
4553 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4554 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4555
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4556<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4557<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4558 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4559 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4560 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4561 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4562</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4563
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4564</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4565
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4566<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4567<h4>
4568 <a name="i_load">'<tt>load</tt>' Instruction</a>
4569</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4570
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4571<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4572
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4573<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4574<pre>
Eli Friedman21006d42011-08-09 23:02:53 +0000[diff] [blame]4575 &lt;result&gt; = [volatile] load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4576 &lt;result&gt; = atomic [volatile] load &lt;ty&gt;* &lt;pointer&gt; [singlethread] &lt;ordering&gt;, align &lt;alignment&gt;
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4577 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4578</pre>
4579
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4580<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4581<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4582
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4583<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4584<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4585 from which to load. The pointer must point to
4586 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4587 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4588 number or order of execution of this <tt>load</tt> with other <a
4589 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4590
Eli Friedman21006d42011-08-09 23:02:53 +0000[diff] [blame]4591<p>If the <code>load</code> is marked as <code>atomic</code>, it takes an extra
4592 <a href="#ordering">ordering</a> and optional <code>singlethread</code>
4593 argument. The <code>release</code> and <code>acq_rel</code> orderings are
4594 not valid on <code>load</code> instructions. Atomic loads produce <a
4595 href="#memorymodel">defined</a> results when they may see multiple atomic
4596 stores. The type of the pointee must be an integer type whose bit width
4597 is a power of two greater than or equal to eight and less than or equal
4598 to a target-specific size limit. <code>align</code> must be explicitly
4599 specified on atomic loads, and the load has undefined behavior if the
4600 alignment is not set to a value which is at least the size in bytes of
4601 the pointee. <code>!nontemporal</code> does not have any defined semantics
4602 for atomic loads.</p>
4603
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4604<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4605 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]4606 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4607 alignment for the target. It is the responsibility of the code emitter to
4608 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4609 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4610 produce less efficient code. An alignment of 1 is always safe.</p>
4611
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4612<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4613 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4614 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4615 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4616 and code generator that this load is not expected to be reused in the cache.
4617 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4618 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4619
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4620<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4621<p>The location of memory pointed to is loaded. If the value being loaded is of
4622 scalar type then the number of bytes read does not exceed the minimum number
4623 of bytes needed to hold all bits of the type. For example, loading an
4624 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4625 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4626 is undefined if the value was not originally written using a store of the
4627 same type.</p>
4628
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4629<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4630<pre>
4631 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4632 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4633 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4634</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4635
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4636</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4637
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4638<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4639<h4>
4640 <a name="i_store">'<tt>store</tt>' Instruction</a>
4641</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4642
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4643<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4644
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4645<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4646<pre>
Eli Friedman21006d42011-08-09 23:02:53 +0000[diff] [blame]4647 [volatile] store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
4648 atomic [volatile] store &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]4649</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4650
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4651<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4652<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4653
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4654<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4655<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4656 and an address at which to store it. The type of the
4657 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4658 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4659 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4660 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4661 order of execution of this <tt>store</tt> with other <a
4662 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4663
Eli Friedman21006d42011-08-09 23:02:53 +0000[diff] [blame]4664<p>If the <code>store</code> is marked as <code>atomic</code>, it takes an extra
4665 <a href="#ordering">ordering</a> and optional <code>singlethread</code>
4666 argument. The <code>acquire</code> and <code>acq_rel</code> orderings aren't
4667 valid on <code>store</code> instructions. Atomic loads produce <a
4668 href="#memorymodel">defined</a> results when they may see multiple atomic
4669 stores. The type of the pointee must be an integer type whose bit width
4670 is a power of two greater than or equal to eight and less than or equal
4671 to a target-specific size limit. <code>align</code> must be explicitly
4672 specified on atomic stores, and the store has undefined behavior if the
4673 alignment is not set to a value which is at least the size in bytes of
4674 the pointee. <code>!nontemporal</code> does not have any defined semantics
4675 for atomic stores.</p>
4676
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4677<p>The optional constant "align" argument specifies the alignment of the
4678 operation (that is, the alignment of the memory address). A value of 0 or an
4679 omitted "align" argument means that the operation has the preferential
4680 alignment for the target. It is the responsibility of the code emitter to
4681 ensure that the alignment information is correct. Overestimating the
4682 alignment results in an undefined behavior. Underestimating the alignment may
4683 produce less efficient code. An alignment of 1 is always safe.</p>
4684
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4685<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4686 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4687 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4688 instruction tells the optimizer and code generator that this load is
4689 not expected to be reused in the cache. The code generator may
4690 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4691 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4692
4693
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4694<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4695<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4696 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4697 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4698 does not exceed the minimum number of bytes needed to hold all bits of the
4699 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4700 writing a value of a type like <tt>i20</tt> with a size that is not an
4701 integral number of bytes, it is unspecified what happens to the extra bits
4702 that do not belong to the type, but they will typically be overwritten.</p>
4703
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4704<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4705<pre>
4706 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4707 store i32 3, i32* %ptr <i>; yields {void}</i>
4708 %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]4709</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4710
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4711</div>
4712
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4713<!-- _______________________________________________________________________ -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4714<h4>
4715<a name="i_fence">'<tt>fence</tt>' Instruction</a>
4716</h4>
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame]4717
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4718<div>
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame]4719
4720<h5>Syntax:</h5>
4721<pre>
4722 fence [singlethread] &lt;ordering&gt; <i>; yields {void}</i>
4723</pre>
4724
4725<h5>Overview:</h5>
4726<p>The '<tt>fence</tt>' instruction is used to introduce happens-before edges
4727between operations.</p>
4728
4729<h5>Arguments:</h5> <p>'<code>fence</code>' instructions take an <a
4730href="#ordering">ordering</a> argument which defines what
4731<i>synchronizes-with</i> edges they add. They can only be given
4732<code>acquire</code>, <code>release</code>, <code>acq_rel</code>, and
4733<code>seq_cst</code> orderings.</p>
4734
4735<h5>Semantics:</h5>
4736<p>A fence <var>A</var> which has (at least) <code>release</code> ordering
4737semantics <i>synchronizes with</i> a fence <var>B</var> with (at least)
4738<code>acquire</code> ordering semantics if and only if there exist atomic
4739operations <var>X</var> and <var>Y</var>, both operating on some atomic object
4740<var>M</var>, such that <var>A</var> is sequenced before <var>X</var>,
4741<var>X</var> modifies <var>M</var> (either directly or through some side effect
4742of a sequence headed by <var>X</var>), <var>Y</var> is sequenced before
4743<var>B</var>, and <var>Y</var> observes <var>M</var>. This provides a
4744<i>happens-before</i> dependency between <var>A</var> and <var>B</var>. Rather
4745than an explicit <code>fence</code>, one (but not both) of the atomic operations
4746<var>X</var> or <var>Y</var> might provide a <code>release</code> or
4747<code>acquire</code> (resp.) ordering constraint and still
4748<i>synchronize-with</i> the explicit <code>fence</code> and establish the
4749<i>happens-before</i> edge.</p>
4750
4751<p>A <code>fence</code> which has <code>seq_cst</code> ordering, in addition to
4752having both <code>acquire</code> and <code>release</code> semantics specified
4753above, participates in the global program order of other <code>seq_cst</code>
4754operations and/or fences.</p>
4755
4756<p>The optional "<a href="#singlethread"><code>singlethread</code></a>" argument
4757specifies that the fence only synchronizes with other fences in the same
4758thread. (This is useful for interacting with signal handlers.)</p>
4759
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame]4760<h5>Example:</h5>
4761<pre>
4762 fence acquire <i>; yields {void}</i>
4763 fence singlethread seq_cst <i>; yields {void}</i>
4764</pre>
4765
4766</div>
4767
4768<!-- _______________________________________________________________________ -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4769<h4>
4770<a name="i_cmpxchg">'<tt>cmpxchg</tt>' Instruction</a>
4771</h4>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4772
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4773<div>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4774
4775<h5>Syntax:</h5>
4776<pre>
4777 [volatile] cmpxchg &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>
4778</pre>
4779
4780<h5>Overview:</h5>
4781<p>The '<tt>cmpxchg</tt>' instruction is used to atomically modify memory.
4782It loads a value in memory and compares it to a given value. If they are
4783equal, it stores a new value into the memory.</p>
4784
4785<h5>Arguments:</h5>
4786<p>There are three arguments to the '<code>cmpxchg</code>' instruction: an
4787address to operate on, a value to compare to the value currently be at that
4788address, and a new value to place at that address if the compared values are
4789equal. The type of '<var>&lt;cmp&gt;</var>' must be an integer type whose
4790bit width is a power of two greater than or equal to eight and less than
4791or equal to a target-specific size limit. '<var>&lt;cmp&gt;</var>' and
4792'<var>&lt;new&gt;</var>' must have the same type, and the type of
4793'<var>&lt;pointer&gt;</var>' must be a pointer to that type. If the
4794<code>cmpxchg</code> is marked as <code>volatile</code>, then the
4795optimizer is not allowed to modify the number or order of execution
4796of this <code>cmpxchg</code> with other <a href="#volatile">volatile
4797operations</a>.</p>
4798
4799<!-- FIXME: Extend allowed types. -->
4800
4801<p>The <a href="#ordering"><var>ordering</var></a> argument specifies how this
4802<code>cmpxchg</code> synchronizes with other atomic operations.</p>
4803
4804<p>The optional "<code>singlethread</code>" argument declares that the
4805<code>cmpxchg</code> is only atomic with respect to code (usually signal
4806handlers) running in the same thread as the <code>cmpxchg</code>. Otherwise the
4807cmpxchg is atomic with respect to all other code in the system.</p>
4808
4809<p>The pointer passed into cmpxchg must have alignment greater than or equal to
4810the size in memory of the operand.
4811
4812<h5>Semantics:</h5>
4813<p>The contents of memory at the location specified by the
4814'<tt>&lt;pointer&gt;</tt>' operand is read and compared to
4815'<tt>&lt;cmp&gt;</tt>'; if the read value is the equal,
4816'<tt>&lt;new&gt;</tt>' is written. The original value at the location
4817is returned.
4818
4819<p>A successful <code>cmpxchg</code> is a read-modify-write instruction for the
4820purpose of identifying <a href="#release_sequence">release sequences</a>. A
4821failed <code>cmpxchg</code> is equivalent to an atomic load with an ordering
4822parameter determined by dropping any <code>release</code> part of the
4823<code>cmpxchg</code>'s ordering.</p>
4824
4825<!--
4826FIXME: Is compare_exchange_weak() necessary? (Consider after we've done
4827optimization work on ARM.)
4828
4829FIXME: Is a weaker ordering constraint on failure helpful in practice?
4830-->
4831
4832<h5>Example:</h5>
4833<pre>
4834entry:
4835 %orig = atomic <a href="#i_load">load</a> i32* %ptr unordered <i>; yields {i32}</i>
4836 <a href="#i_br">br</a> label %loop
4837
4838loop:
4839 %cmp = <a href="#i_phi">phi</a> i32 [ %orig, %entry ], [%old, %loop]
4840 %squared = <a href="#i_mul">mul</a> i32 %cmp, %cmp
4841 %old = cmpxchg i32* %ptr, i32 %cmp, i32 %squared <i>; yields {i32}</i>
4842 %success = <a href="#i_icmp">icmp</a> eq i32 %cmp, %old
4843 <a href="#i_br">br</a> i1 %success, label %done, label %loop
4844
4845done:
4846 ...
4847</pre>
4848
4849</div>
4850
4851<!-- _______________________________________________________________________ -->
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4852<h4>
4853<a name="i_atomicrmw">'<tt>atomicrmw</tt>' Instruction</a>
4854</h4>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4855
NAKAMURA Takumib5bb29c2011-08-12 06:17:17 +0000[diff] [blame]4856<div>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4857
4858<h5>Syntax:</h5>
4859<pre>
4860 [volatile] atomicrmw &lt;operation&gt; &lt;ty&gt;* &lt;pointer&gt;, &lt;ty&gt; &lt;value&gt; [singlethread] &lt;ordering&gt; <i>; yields {ty}</i>
4861</pre>
4862
4863<h5>Overview:</h5>
4864<p>The '<tt>atomicrmw</tt>' instruction is used to atomically modify memory.</p>
4865
4866<h5>Arguments:</h5>
4867<p>There are three arguments to the '<code>atomicrmw</code>' instruction: an
4868operation to apply, an address whose value to modify, an argument to the
4869operation. The operation must be one of the following keywords:</p>
4870<ul>
4871 <li>xchg</li>
4872 <li>add</li>
4873 <li>sub</li>
4874 <li>and</li>
4875 <li>nand</li>
4876 <li>or</li>
4877 <li>xor</li>
4878 <li>max</li>
4879 <li>min</li>
4880 <li>umax</li>
4881 <li>umin</li>
4882</ul>
4883
4884<p>The type of '<var>&lt;value&gt;</var>' must be an integer type whose
4885bit width is a power of two greater than or equal to eight and less than
4886or equal to a target-specific size limit. The type of the
4887'<code>&lt;pointer&gt;</code>' operand must be a pointer to that type.
4888If the <code>atomicrmw</code> is marked as <code>volatile</code>, then the
4889optimizer is not allowed to modify the number or order of execution of this
4890<code>atomicrmw</code> with other <a href="#volatile">volatile
4891 operations</a>.</p>
4892
4893<!-- FIXME: Extend allowed types. -->
4894
4895<h5>Semantics:</h5>
4896<p>The contents of memory at the location specified by the
4897'<tt>&lt;pointer&gt;</tt>' operand are atomically read, modified, and written
4898back. The original value at the location is returned. The modification is
4899specified by the <var>operation</var> argument:</p>
4900
4901<ul>
4902 <li>xchg: <code>*ptr = val</code></li>
4903 <li>add: <code>*ptr = *ptr + val</code></li>
4904 <li>sub: <code>*ptr = *ptr - val</code></li>
4905 <li>and: <code>*ptr = *ptr &amp; val</code></li>
4906 <li>nand: <code>*ptr = ~(*ptr &amp; val)</code></li>
4907 <li>or: <code>*ptr = *ptr | val</code></li>
4908 <li>xor: <code>*ptr = *ptr ^ val</code></li>
4909 <li>max: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using a signed comparison)</li>
4910 <li>min: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using a signed comparison)</li>
4911 <li>umax: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4912 <li>umin: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4913</ul>
4914
4915<h5>Example:</h5>
4916<pre>
4917 %old = atomicrmw add i32* %ptr, i32 1 acquire <i>; yields {i32}</i>
4918</pre>
4919
4920</div>
4921
4922<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4923<h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4924 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4925</h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4926
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4927<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4928
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4929<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4930<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4931 &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]4932 &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]4933</pre>
4934
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4935<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4936<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4937 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4938 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4939
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4940<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4941<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4942 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4943 elements of the aggregate object are indexed. The interpretation of each
4944 index is dependent on the type being indexed into. The first index always
4945 indexes the pointer value given as the first argument, the second index
4946 indexes a value of the type pointed to (not necessarily the value directly
4947 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4948 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4949 vectors, and structs. Note that subsequent types being indexed into
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4950 can never be pointers, since that would require loading the pointer before
4951 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4952
4953<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]4954 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4955 integer <b>constants</b> are allowed. When indexing into an array, pointer
4956 or vector, integers of any width are allowed, and they are not required to be
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4957 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4958
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4959<p>For example, let's consider a C code fragment and how it gets compiled to
4960 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4961
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4962<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4963struct RT {
4964 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4965 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4966 char C;
4967};
4968struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4969 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4970 double Y;
4971 struct RT Z;
4972};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4973
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4974int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4975 return &amp;s[1].Z.B[5][13];
4976}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4977</pre>
4978
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4979<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4980
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4981<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]4982%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4983%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4984
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4985define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4986entry:
4987 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4988 ret i32* %reg
4989}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4990</pre>
4991
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4992<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4993<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]4994 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4995 }</tt>' type, a structure. The second index indexes into the third element
4996 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4997 i8 }</tt>' type, another structure. The third index indexes into the second
4998 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4999 array. The two dimensions of the array are subscripted into, yielding an
5000 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
5001 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5002
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5003<p>Note that it is perfectly legal to index partially through a structure,
5004 returning a pointer to an inner element. Because of this, the LLVM code for
5005 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5006
5007<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]5008 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5009 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]5010 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
5011 %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]5012 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
5013 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
5014 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5015 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5016</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]5017
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]5018<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]5019 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
5020 base pointer is not an <i>in bounds</i> address of an allocated object,
5021 or if any of the addresses that would be formed by successive addition of
5022 the offsets implied by the indices to the base address with infinitely
5023 precise arithmetic are not an <i>in bounds</i> address of that allocated
5024 object. The <i>in bounds</i> addresses for an allocated object are all
5025 the addresses that point into the object, plus the address one byte past
5026 the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]5027
5028<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
5029 the base address with silently-wrapping two's complement arithmetic, and
5030 the result value of the <tt>getelementptr</tt> may be outside the object
5031 pointed to by the base pointer. The result value may not necessarily be
5032 used to access memory though, even if it happens to point into allocated
5033 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
5034 section for more information.</p>
5035
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5036<p>The getelementptr instruction is often confusing. For some more insight into
5037 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]5038
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]5039<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5040<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5041 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]5042 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
5043 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5044 %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]5045 <i>; yields i8*:eptr</i>
5046 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]5047 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]5048 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5049</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5050
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5051</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]5052
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5053</div>
5054
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5055<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5056<h3>
5057 <a name="convertops">Conversion Operations</a>
5058</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5059
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5060<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5061
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5062<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5063 which all take a single operand and a type. They perform various bit
5064 conversions on the operand.</p>
5065
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5066<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5067<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5068 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5069</h4>
5070
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5071<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5072
5073<h5>Syntax:</h5>
5074<pre>
5075 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5076</pre>
5077
5078<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5079<p>The '<tt>trunc</tt>' instruction truncates its operand to the
5080 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5081
5082<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5083<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
5084 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5085 of the same number of integers.
5086 The bit size of the <tt>value</tt> must be larger than
5087 the bit size of the destination type, <tt>ty2</tt>.
5088 Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5089
5090<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5091<p>The '<tt>trunc</tt>' instruction truncates the high order bits
5092 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
5093 source size must be larger than the destination size, <tt>trunc</tt> cannot
5094 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5095
5096<h5>Example:</h5>
5097<pre>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5098 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
5099 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
5100 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
5101 %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]5102</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5103
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5104</div>
5105
5106<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5107<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5108 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5109</h4>
5110
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5111<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5112
5113<h5>Syntax:</h5>
5114<pre>
5115 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5116</pre>
5117
5118<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5119<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5120 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5121
5122
5123<h5>Arguments:</h5>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]5124<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
5125 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5126 of the same number of integers.
5127 The bit size of the <tt>value</tt> must be smaller than
5128 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5129 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5130
5131<h5>Semantics:</h5>
5132<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]5133 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5134
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]5135<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]5136
5137<h5>Example:</h5>
5138<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5139 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5140 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]5141 %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]5142</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5143
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5144</div>
5145
5146<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5147<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5148 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5149</h4>
5150
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5151<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5152
5153<h5>Syntax:</h5>
5154<pre>
5155 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5156</pre>
5157
5158<h5>Overview:</h5>
5159<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
5160
5161<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5162<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
5163 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5164 of the same number of integers.
5165 The bit size of the <tt>value</tt> must be smaller than
5166 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5167 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5168
5169<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5170<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
5171 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
5172 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5173
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5174<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]5175
5176<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5177<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5178 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5179 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5180 %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]5181</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5182
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5183</div>
5184
5185<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5186<h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5187 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5188</h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5189
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5190<div>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5191
5192<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5193<pre>
5194 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5195</pre>
5196
5197<h5>Overview:</h5>
5198<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5199 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5200
5201<h5>Arguments:</h5>
5202<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5203 point</a> value to cast and a <a href="#t_floating">floating point</a> type
5204 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]5205 <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]5206 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5207
5208<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5209<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5210 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5211 <a href="#t_floating">floating point</a> type. If the value cannot fit
5212 within the destination type, <tt>ty2</tt>, then the results are
5213 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5214
5215<h5>Example:</h5>
5216<pre>
5217 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
5218 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
5219</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5220
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5221</div>
5222
5223<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5224<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5225 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5226</h4>
5227
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5228<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5229
5230<h5>Syntax:</h5>
5231<pre>
5232 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5233</pre>
5234
5235<h5>Overview:</h5>
5236<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]5237 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5238
5239<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5240<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5241 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
5242 a <a href="#t_floating">floating point</a> type to cast it to. The source
5243 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5244
5245<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5246<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5247 <a href="#t_floating">floating point</a> type to a larger
5248 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
5249 used to make a <i>no-op cast</i> because it always changes bits. Use
5250 <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]5251
5252<h5>Example:</h5>
5253<pre>
Nick Lewycky5bb3ece2011-03-31 18:20:19 +0000[diff] [blame]5254 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
5255 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5256</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5257
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5258</div>
5259
5260<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5261<h4>
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]5262 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5263</h4>
5264
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5265<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5266
5267<h5>Syntax:</h5>
5268<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5269 &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]5270</pre>
5271
5272<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5273<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5274 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5275
5276<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5277<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
5278 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5279 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5280 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5281 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5282
5283<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5284<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5285 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5286 towards zero) unsigned integer value. If the value cannot fit
5287 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5288
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5289<h5>Example:</h5>
5290<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5291 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]5292 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5293 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5294</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5295
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5296</div>
5297
5298<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5299<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5300 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5301</h4>
5302
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5303<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5304
5305<h5>Syntax:</h5>
5306<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5307 &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]5308</pre>
5309
5310<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5311<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5312 <a href="#t_floating">floating point</a> <tt>value</tt> to
5313 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5314
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5315<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5316<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
5317 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5318 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5319 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5320 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5321
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5322<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5323<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5324 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5325 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
5326 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5327
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]5328<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5329<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5330 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]5331 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5332 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5333</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5334
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5335</div>
5336
5337<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5338<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5339 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5340</h4>
5341
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5342<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5343
5344<h5>Syntax:</h5>
5345<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5346 &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]5347</pre>
5348
5349<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5350<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5351 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5352
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5353<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5354<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]5355 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5356 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5357 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5358 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5359
5360<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5361<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5362 integer quantity and converts it to the corresponding floating point
5363 value. If the value cannot fit in the floating point value, the results are
5364 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5365
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5366<h5>Example:</h5>
5367<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5368 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5369 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5370</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5371
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5372</div>
5373
5374<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5375<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5376 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5377</h4>
5378
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5379<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5380
5381<h5>Syntax:</h5>
5382<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5383 &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]5384</pre>
5385
5386<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5387<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5388 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5389
5390<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5391<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]5392 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5393 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5394 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5395 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5396
5397<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5398<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5399 quantity and converts it to the corresponding floating point value. If the
5400 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5401
5402<h5>Example:</h5>
5403<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5404 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5405 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5406</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5407
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5408</div>
5409
5410<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5411<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5412 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5413</h4>
5414
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5415<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5416
5417<h5>Syntax:</h5>
5418<pre>
5419 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5420</pre>
5421
5422<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5423<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5424 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5425
5426<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5427<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5428 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5429 <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]5430
5431<h5>Semantics:</h5>
5432<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5433 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5434 truncating or zero extending that value to the size of the integer type. If
5435 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5436 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5437 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5438 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5439
5440<h5>Example:</h5>
5441<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5442 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5443 %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]5444</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5445
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5446</div>
5447
5448<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5449<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5450 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5451</h4>
5452
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5453<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5454
5455<h5>Syntax:</h5>
5456<pre>
5457 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5458</pre>
5459
5460<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5461<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5462 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5463
5464<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]5465<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5466 value to cast, and a type to cast it to, which must be a
5467 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5468
5469<h5>Semantics:</h5>
5470<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5471 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5472 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5473 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5474 than the size of a pointer then a zero extension is done. If they are the
5475 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5476
5477<h5>Example:</h5>
5478<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5479 %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]5480 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5481 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5482</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5483
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5484</div>
5485
5486<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5487<h4>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5488 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5489</h4>
5490
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5491<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5492
5493<h5>Syntax:</h5>
5494<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5495 &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]5496</pre>
5497
5498<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5499<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5500 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5501
5502<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5503<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5504 non-aggregate first class value, and a type to cast it to, which must also be
5505 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5506 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5507 identical. If the source type is a pointer, the destination type must also be
5508 a pointer. This instruction supports bitwise conversion of vectors to
5509 integers and to vectors of other types (as long as they have the same
5510 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5511
5512<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5513<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5514 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5515 this conversion. The conversion is done as if the <tt>value</tt> had been
5516 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5517 be converted to other pointer types with this instruction. To convert
5518 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5519 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5520
5521<h5>Example:</h5>
5522<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5523 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5524 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5525 %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]5526</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5527
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5528</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5529
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5530</div>
5531
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5532<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5533<h3>
5534 <a name="otherops">Other Operations</a>
5535</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5536
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5537<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5538
5539<p>The instructions in this category are the "miscellaneous" instructions, which
5540 defy better classification.</p>
5541
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5542<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5543<h4>
5544 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5545</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5546
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5547<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5548
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5549<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5550<pre>
5551 &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]5552</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5553
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5554<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5555<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5556 boolean values based on comparison of its two integer, integer vector, or
5557 pointer operands.</p>
5558
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5559<h5>Arguments:</h5>
5560<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5561 the condition code indicating the kind of comparison to perform. It is not a
5562 value, just a keyword. The possible condition code are:</p>
5563
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5564<ol>
5565 <li><tt>eq</tt>: equal</li>
5566 <li><tt>ne</tt>: not equal </li>
5567 <li><tt>ugt</tt>: unsigned greater than</li>
5568 <li><tt>uge</tt>: unsigned greater or equal</li>
5569 <li><tt>ult</tt>: unsigned less than</li>
5570 <li><tt>ule</tt>: unsigned less or equal</li>
5571 <li><tt>sgt</tt>: signed greater than</li>
5572 <li><tt>sge</tt>: signed greater or equal</li>
5573 <li><tt>slt</tt>: signed less than</li>
5574 <li><tt>sle</tt>: signed less or equal</li>
5575</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5576
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]5577<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5578 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5579 typed. They must also be identical types.</p>
5580
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5581<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5582<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5583 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5584 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]5585 result, as follows:</p>
5586
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5587<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5588 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5589 <tt>false</tt> otherwise. No sign interpretation is necessary or
5590 performed.</li>
5591
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5592 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5593 <tt>false</tt> otherwise. No sign interpretation is necessary or
5594 performed.</li>
5595
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5596 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5597 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5598
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5599 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5600 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5601 to <tt>op2</tt>.</li>
5602
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5603 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5604 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5605
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5606 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5607 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5608
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5609 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5610 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5611
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5612 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5613 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5614 to <tt>op2</tt>.</li>
5615
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5616 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5617 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5618
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5619 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5620 <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]5621</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5622
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5623<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5624 values are compared as if they were integers.</p>
5625
5626<p>If the operands are integer vectors, then they are compared element by
5627 element. The result is an <tt>i1</tt> vector with the same number of elements
5628 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5629
5630<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5631<pre>
5632 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5633 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5634 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5635 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5636 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5637 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5638</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5639
5640<p>Note that the code generator does not yet support vector types with
5641 the <tt>icmp</tt> instruction.</p>
5642
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5643</div>
5644
5645<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5646<h4>
5647 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5648</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5649
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5650<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5651
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5652<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5653<pre>
5654 &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]5655</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5656
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5657<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5658<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5659 values based on comparison of its operands.</p>
5660
5661<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]5662(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5663
5664<p>If the operands are floating point vectors, then the result type is a vector
5665 of boolean with the same number of elements as the operands being
5666 compared.</p>
5667
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5668<h5>Arguments:</h5>
5669<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5670 the condition code indicating the kind of comparison to perform. It is not a
5671 value, just a keyword. The possible condition code are:</p>
5672
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5673<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5674 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5675 <li><tt>oeq</tt>: ordered and equal</li>
5676 <li><tt>ogt</tt>: ordered and greater than </li>
5677 <li><tt>oge</tt>: ordered and greater than or equal</li>
5678 <li><tt>olt</tt>: ordered and less than </li>
5679 <li><tt>ole</tt>: ordered and less than or equal</li>
5680 <li><tt>one</tt>: ordered and not equal</li>
5681 <li><tt>ord</tt>: ordered (no nans)</li>
5682 <li><tt>ueq</tt>: unordered or equal</li>
5683 <li><tt>ugt</tt>: unordered or greater than </li>
5684 <li><tt>uge</tt>: unordered or greater than or equal</li>
5685 <li><tt>ult</tt>: unordered or less than </li>
5686 <li><tt>ule</tt>: unordered or less than or equal</li>
5687 <li><tt>une</tt>: unordered or not equal</li>
5688 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5689 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5690</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5691
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5692<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5693 <i>unordered</i> means that either operand may be a QNAN.</p>
5694
5695<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5696 a <a href="#t_floating">floating point</a> type or
5697 a <a href="#t_vector">vector</a> of floating point type. They must have
5698 identical types.</p>
5699
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5700<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]5701<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5702 according to the condition code given as <tt>cond</tt>. If the operands are
5703 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5704 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5705 follows:</p>
5706
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5707<ol>
5708 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5709
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5710 <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]5711 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5712
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5713 <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]5714 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5715
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5716 <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]5717 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5718
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5719 <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]5720 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5721
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5722 <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]5723 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5724
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5725 <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]5726 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5727
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5728 <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]5729
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5730 <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]5731 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5732
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5733 <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]5734 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5735
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5736 <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]5737 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5738
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5739 <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]5740 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5741
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5742 <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]5743 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5744
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5745 <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]5746 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5747
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5748 <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]5749
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5750 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5751</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5752
5753<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5754<pre>
5755 &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]5756 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5757 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5758 &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]5759</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5760
5761<p>Note that the code generator does not yet support vector types with
5762 the <tt>fcmp</tt> instruction.</p>
5763
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5764</div>
5765
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5766<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5767<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5768 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5769</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5770
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5771<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5772
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5773<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5774<pre>
5775 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5776</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5777
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5778<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5779<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5780 SSA graph representing the function.</p>
5781
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5782<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5783<p>The type of the incoming values is specified with the first type field. After
5784 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5785 one pair for each predecessor basic block of the current block. Only values
5786 of <a href="#t_firstclass">first class</a> type may be used as the value
5787 arguments to the PHI node. Only labels may be used as the label
5788 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5789
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5790<p>There must be no non-phi instructions between the start of a basic block and
5791 the PHI instructions: i.e. PHI instructions must be first in a basic
5792 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5793
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5794<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5795 occur on the edge from the corresponding predecessor block to the current
5796 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5797 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]5798
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5799<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5800<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5801 specified by the pair corresponding to the predecessor basic block that
5802 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5803
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5804<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5805<pre>
5806Loop: ; Infinite loop that counts from 0 on up...
5807 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5808 %nextindvar = add i32 %indvar, 1
5809 br label %Loop
5810</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5811
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5812</div>
5813
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5814<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5815<h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5816 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5817</h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5818
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5819<div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5820
5821<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5822<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5823 &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>
5824
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5825 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5826</pre>
5827
5828<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5829<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5830 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5831
5832
5833<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5834<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5835 values indicating the condition, and two values of the
5836 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5837 vectors and the condition is a scalar, then entire vectors are selected, not
5838 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5839
5840<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5841<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5842 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5843
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5844<p>If the condition is a vector of i1, then the value arguments must be vectors
5845 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5846
5847<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5848<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5849 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5850</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5851
5852<p>Note that the code generator does not yet support conditions
5853 with vector type.</p>
5854
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5855</div>
5856
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5857<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5858<h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5859 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5860</h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5861
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5862<div>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5863
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5864<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5865<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]5866 &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]5867</pre>
5868
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5869<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5870<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5871
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5872<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5873<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5874
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5875<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5876 <li>The optional "tail" marker indicates that the callee function does not
5877 access any allocas or varargs in the caller. Note that calls may be
5878 marked "tail" even if they do not occur before
5879 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5880 present, the function call is eligible for tail call optimization,
5881 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Chengdc444e92010-03-08 21:05:02 +0000[diff] [blame]5882 optimized into a jump</a>. The code generator may optimize calls marked
5883 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5884 sibling call optimization</a> when the caller and callee have
5885 matching signatures, or 2) forced tail call optimization when the
5886 following extra requirements are met:
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5887 <ul>
5888 <li>Caller and callee both have the calling
5889 convention <tt>fastcc</tt>.</li>
5890 <li>The call is in tail position (ret immediately follows call and ret
5891 uses value of call or is void).</li>
5892 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohmanfbbee8d2010-03-02 01:08:11 +0000[diff] [blame]5893 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5894 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5895 constraints are met.</a></li>
5896 </ul>
5897 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5898
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5899 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5900 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5901 defaults to using C calling conventions. The calling convention of the
5902 call must match the calling convention of the target function, or else the
5903 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5904
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5905 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5906 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5907 '<tt>inreg</tt>' attributes are valid here.</li>
5908
5909 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5910 type of the return value. Functions that return no value are marked
5911 <tt><a href="#t_void">void</a></tt>.</li>
5912
5913 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5914 being invoked. The argument types must match the types implied by this
5915 signature. This type can be omitted if the function is not varargs and if
5916 the function type does not return a pointer to a function.</li>
5917
5918 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5919 be invoked. In most cases, this is a direct function invocation, but
5920 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5921 to function value.</li>
5922
5923 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]5924 signature argument types and parameter attributes. All arguments must be
5925 of <a href="#t_firstclass">first class</a> type. If the function
5926 signature indicates the function accepts a variable number of arguments,
5927 the extra arguments can be specified.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5928
5929 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5930 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5931 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5932</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5933
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5934<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5935<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5936 a specified function, with its incoming arguments bound to the specified
5937 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5938 function, control flow continues with the instruction after the function
5939 call, and the return value of the function is bound to the result
5940 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5941
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5942<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5943<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]5944 %retval = call i32 @test(i32 %argc)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]5945 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]5946 %X = tail call i32 @foo() <i>; yields i32</i>
5947 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5948 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]5949
5950 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5951 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]5952 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5953 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]5954 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]5955 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5956</pre>
5957
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5958<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]5959standard C99 library as being the C99 library functions, and may perform
5960optimizations or generate code for them under that assumption. This is
5961something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5962freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5963
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5964</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5965
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5966<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5967<h4>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]5968 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5969</h4>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5970
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5971<div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5972
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5973<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5974<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5975 &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]5976</pre>
5977
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5978<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5979<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5980 the "variable argument" area of a function call. It is used to implement the
5981 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5982
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5983<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5984<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5985 argument. It returns a value of the specified argument type and increments
5986 the <tt>va_list</tt> to point to the next argument. The actual type
5987 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5988
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5989<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5990<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5991 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5992 to the next argument. For more information, see the variable argument
5993 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5994
5995<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]5996 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5997 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5998
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5999<p><tt>va_arg</tt> is an LLVM instruction instead of
6000 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
6001 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6002
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]6003<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]6004<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
6005
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6006<p>Note that the code generator does not yet fully support va_arg on many
6007 targets. Also, it does not currently support va_arg with aggregate types on
6008 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]6009
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6010</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6011
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6012<!-- _______________________________________________________________________ -->
6013<h4>
6014 <a name="i_landingpad">'<tt>landingpad</tt>' Instruction</a>
6015</h4>
6016
6017<div>
6018
6019<h5>Syntax:</h5>
6020<pre>
Bill Wendlingbf13ee12011-08-08 08:06:05 +0000[diff] [blame]6021 &lt;resultval&gt; = landingpad &lt;somety&gt; personality &lt;type&gt; &lt;pers_fn&gt; &lt;clause&gt;+
6022 &lt;resultval&gt; = landingpad &lt;somety&gt; personality &lt;type&gt; &lt;pers_fn&gt; cleanup &lt;clause&gt;*
6023
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6024 &lt;clause&gt; := catch &lt;type&gt; &lt;value&gt;
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame^]6025 &lt;clause&gt; := filter &lt;array constant type&gt; &lt;array constant&gt;
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6026</pre>
6027
6028<h5>Overview:</h5>
6029<p>The '<tt>landingpad</tt>' instruction is used by
6030 <a href="ExceptionHandling.html#overview">LLVM's exception handling
6031 system</a> to specify that a basic block is a landing pad &mdash; one where
6032 the exception lands, and corresponds to the code found in the
6033 <i><tt>catch</tt></i> portion of a <i><tt>try/catch</tt></i> sequence. It
6034 defines values supplied by the personality function (<tt>pers_fn</tt>) upon
6035 re-entry to the function. The <tt>resultval</tt> has the
6036 type <tt>somety</tt>.</p>
6037
6038<h5>Arguments:</h5>
6039<p>This instruction takes a <tt>pers_fn</tt> value. This is the personality
6040 function associated with the unwinding mechanism. The optional
6041 <tt>cleanup</tt> flag indicates that the landing pad block is a cleanup.</p>
6042
6043<p>A <tt>clause</tt> begins with the clause type &mdash; <tt>catch</tt>
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame^]6044 or <tt>filter</tt> &mdash; and contains the global variable representing the
6045 "type" that may be caught or filtered respectively. Unlike the
6046 <tt>catch</tt> clause, the <tt>filter</tt> clause takes an array constant as
6047 its argument. Use "<tt>[0 x i8**] undef</tt>" for a filter which cannot
6048 throw. The '<tt>landingpad</tt>' instruction must contain <em>at least</em>
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6049 one <tt>clause</tt> or the <tt>cleanup</tt> flag.</p>
6050
6051<h5>Semantics:</h5>
6052<p>The '<tt>landingpad</tt>' instruction defines the values which are set by the
6053 personality function (<tt>pers_fn</tt>) upon re-entry to the function, and
6054 therefore the "result type" of the <tt>landingpad</tt> instruction. As with
6055 calling conventions, how the personality function results are represented in
6056 LLVM IR is target specific.</p>
6057
Bill Wendlingb7a01352011-08-03 17:17:06 +0000[diff] [blame]6058<p>The clauses are applied in order from top to bottom. If two
6059 <tt>landingpad</tt> instructions are merged together through inlining, the
Bill Wendling2905c322011-08-08 07:58:58 +0000[diff] [blame]6060 clauses from the calling function are appended to the list of clauses.</p>
Bill Wendlingb7a01352011-08-03 17:17:06 +0000[diff] [blame]6061
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6062<p>The <tt>landingpad</tt> instruction has several restrictions:</p>
6063
6064<ul>
6065 <li>A landing pad block is a basic block which is the unwind destination of an
6066 '<tt>invoke</tt>' instruction.</li>
6067 <li>A landing pad block must have a '<tt>landingpad</tt>' instruction as its
6068 first non-PHI instruction.</li>
6069 <li>There can be only one '<tt>landingpad</tt>' instruction within the landing
6070 pad block.</li>
6071 <li>A basic block that is not a landing pad block may not include a
6072 '<tt>landingpad</tt>' instruction.</li>
6073 <li>All '<tt>landingpad</tt>' instructions in a function must have the same
6074 personality function.</li>
6075</ul>
6076
6077<h5>Example:</h5>
6078<pre>
6079 ;; A landing pad which can catch an integer.
6080 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
6081 catch i8** @_ZTIi
6082 ;; A landing pad that is a cleanup.
6083 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame^]6084 cleanup
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6085 ;; A landing pad which can catch an integer and can only throw a double.
6086 %res = landingpad { i8*, i32 } personality i32 (...)* @__gxx_personality_v0
6087 catch i8** @_ZTIi
Bill Wendlinge6e88262011-08-12 20:24:12 +0000[diff] [blame^]6088 filter [1 x i8**] [@_ZTId]
Bill Wendlingf78faf82011-08-02 21:52:38 +0000[diff] [blame]6089</pre>
6090
6091</div>
6092
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6093</div>
6094
6095</div>
6096
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6097<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6098<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]6099<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6100
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6101<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6102
6103<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6104 well known names and semantics and are required to follow certain
6105 restrictions. Overall, these intrinsics represent an extension mechanism for
6106 the LLVM language that does not require changing all of the transformations
6107 in LLVM when adding to the language (or the bitcode reader/writer, the
6108 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6109
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]6110<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6111 prefix is reserved in LLVM for intrinsic names; thus, function names may not
6112 begin with this prefix. Intrinsic functions must always be external
6113 functions: you cannot define the body of intrinsic functions. Intrinsic
6114 functions may only be used in call or invoke instructions: it is illegal to
6115 take the address of an intrinsic function. Additionally, because intrinsic
6116 functions are part of the LLVM language, it is required if any are added that
6117 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6118
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6119<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
6120 family of functions that perform the same operation but on different data
6121 types. Because LLVM can represent over 8 million different integer types,
6122 overloading is used commonly to allow an intrinsic function to operate on any
6123 integer type. One or more of the argument types or the result type can be
6124 overloaded to accept any integer type. Argument types may also be defined as
6125 exactly matching a previous argument's type or the result type. This allows
6126 an intrinsic function which accepts multiple arguments, but needs all of them
6127 to be of the same type, to only be overloaded with respect to a single
6128 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6129
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6130<p>Overloaded intrinsics will have the names of its overloaded argument types
6131 encoded into its function name, each preceded by a period. Only those types
6132 which are overloaded result in a name suffix. Arguments whose type is matched
6133 against another type do not. For example, the <tt>llvm.ctpop</tt> function
6134 can take an integer of any width and returns an integer of exactly the same
6135 integer width. This leads to a family of functions such as
6136 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
6137 %val)</tt>. Only one type, the return type, is overloaded, and only one type
6138 suffix is required. Because the argument's type is matched against the return
6139 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6140
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6141<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6142 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6143
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6144<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6145<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6146 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6147</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6148
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6149<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6150
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6151<p>Variable argument support is defined in LLVM with
6152 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
6153 intrinsic functions. These functions are related to the similarly named
6154 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6155
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6156<p>All of these functions operate on arguments that use a target-specific value
6157 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
6158 not define what this type is, so all transformations should be prepared to
6159 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6160
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]6161<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]6162 instruction and the variable argument handling intrinsic functions are
6163 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6164
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]6165<pre class="doc_code">
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6166define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6167 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6168 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6169 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6170 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6171
6172 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6173 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6174
6175 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6176 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6177 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6178 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6179 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6180
6181 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6182 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]6183 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6184}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6185
6186declare void @llvm.va_start(i8*)
6187declare void @llvm.va_copy(i8*, i8*)
6188declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6189</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6190
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6191<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6192<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6193 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6194</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6195
6196
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6197<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6198
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6199<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6200<pre>
6201 declare void %llvm.va_start(i8* &lt;arglist&gt;)
6202</pre>
6203
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6204<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6205<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
6206 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]6207
6208<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6209<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]6210
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6211<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6212<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]6213 macro available in C. In a target-dependent way, it initializes
6214 the <tt>va_list</tt> element to which the argument points, so that the next
6215 call to <tt>va_arg</tt> will produce the first variable argument passed to
6216 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
6217 need to know the last argument of the function as the compiler can figure
6218 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6219
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6220</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6221
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6222<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6223<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6224 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6225</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6226
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6227<div>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6228
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6229<h5>Syntax:</h5>
6230<pre>
6231 declare void @llvm.va_end(i8* &lt;arglist&gt;)
6232</pre>
6233
6234<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6235<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6236 which has been initialized previously
6237 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
6238 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6239
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6240<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6241<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]6242
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6243<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6244<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]6245 macro available in C. In a target-dependent way, it destroys
6246 the <tt>va_list</tt> element to which the argument points. Calls
6247 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
6248 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
6249 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6250
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6251</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6252
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6253<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6254<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6255 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6256</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6257
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6258<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6259
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6260<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6261<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6262 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6263</pre>
6264
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6265<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6266<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6267 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6268
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6269<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6270<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]6271 The second argument is a pointer to a <tt>va_list</tt> element to copy
6272 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6273
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6274<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6275<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]6276 macro available in C. In a target-dependent way, it copies the
6277 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
6278 element. This intrinsic is necessary because
6279 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
6280 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6281
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6282</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6283
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6284</div>
6285
Bill Wendling0246bb72011-07-31 06:45:03 +0000[diff] [blame]6286</div>
6287
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6288<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6289<h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6290 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6291</h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6292
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6293<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6294
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6295<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]6296Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6297intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
6298roots on the stack</a>, as well as garbage collector implementations that
6299require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
6300barriers. Front-ends for type-safe garbage collected languages should generate
6301these intrinsics to make use of the LLVM garbage collectors. For more details,
6302see <a href="GarbageCollection.html">Accurate Garbage Collection with
6303LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]6304
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6305<p>The garbage collection intrinsics only operate on objects in the generic
6306 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]6307
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6308<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6309<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6310 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6311</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6312
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6313<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6314
6315<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6316<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6317 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6318</pre>
6319
6320<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]6321<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]6322 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6323
6324<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6325<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6326 root pointer. The second pointer (which must be either a constant or a
6327 global value address) contains the meta-data to be associated with the
6328 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6329
6330<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]6331<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]6332 location. At compile-time, the code generator generates information to allow
6333 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
6334 intrinsic may only be used in a function which <a href="#gc">specifies a GC
6335 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6336
6337</div>
6338
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6339<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6340<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6341 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6342</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6343
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6344<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6345
6346<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6347<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6348 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6349</pre>
6350
6351<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6352<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6353 locations, allowing garbage collector implementations that require read
6354 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6355
6356<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]6357<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]6358 allocated from the garbage collector. The first object is a pointer to the
6359 start of the referenced object, if needed by the language runtime (otherwise
6360 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6361
6362<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6363<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6364 instruction, but may be replaced with substantially more complex code by the
6365 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
6366 may only be used in a function which <a href="#gc">specifies a GC
6367 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6368
6369</div>
6370
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6371<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6372<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6373 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6374</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6375
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6376<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6377
6378<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6379<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6380 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6381</pre>
6382
6383<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6384<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6385 locations, allowing garbage collector implementations that require write
6386 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6387
6388<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]6389<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]6390 object to store it to, and the third is the address of the field of Obj to
6391 store to. If the runtime does not require a pointer to the object, Obj may
6392 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6393
6394<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6395<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6396 instruction, but may be replaced with substantially more complex code by the
6397 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
6398 may only be used in a function which <a href="#gc">specifies a GC
6399 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6400
6401</div>
6402
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6403</div>
6404
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6405<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6406<h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6407 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6408</h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6409
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6410<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6411
6412<p>These intrinsics are provided by LLVM to expose special features that may
6413 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6414
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6415<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6416<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6417 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6418</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6419
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6420<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6421
6422<h5>Syntax:</h5>
6423<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6424 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6425</pre>
6426
6427<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6428<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
6429 target-specific value indicating the return address of the current function
6430 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6431
6432<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6433<p>The argument to this intrinsic indicates which function to return the address
6434 for. Zero indicates the calling function, one indicates its caller, etc.
6435 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6436
6437<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6438<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
6439 indicating the return address of the specified call frame, or zero if it
6440 cannot be identified. The value returned by this intrinsic is likely to be
6441 incorrect or 0 for arguments other than zero, so it should only be used for
6442 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6443
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6444<p>Note that calling this intrinsic does not prevent function inlining or other
6445 aggressive transformations, so the value returned may not be that of the
6446 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6447
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6448</div>
6449
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6450<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6451<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6452 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6453</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6454
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6455<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6456
6457<h5>Syntax:</h5>
6458<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6459 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6460</pre>
6461
6462<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6463<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6464 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6465
6466<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6467<p>The argument to this intrinsic indicates which function to return the frame
6468 pointer for. Zero indicates the calling function, one indicates its caller,
6469 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6470
6471<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6472<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6473 indicating the frame address of the specified call frame, or zero if it
6474 cannot be identified. The value returned by this intrinsic is likely to be
6475 incorrect or 0 for arguments other than zero, so it should only be used for
6476 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6477
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6478<p>Note that calling this intrinsic does not prevent function inlining or other
6479 aggressive transformations, so the value returned may not be that of the
6480 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6481
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6482</div>
6483
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6484<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6485<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6486 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6487</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6488
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6489<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6490
6491<h5>Syntax:</h5>
6492<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6493 declare i8* @llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6494</pre>
6495
6496<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6497<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6498 of the function stack, for use
6499 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6500 useful for implementing language features like scoped automatic variable
6501 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6502
6503<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6504<p>This intrinsic returns a opaque pointer value that can be passed
6505 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6506 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6507 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6508 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6509 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6510 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6511
6512</div>
6513
6514<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6515<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6516 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6517</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6518
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6519<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6520
6521<h5>Syntax:</h5>
6522<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6523 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6524</pre>
6525
6526<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6527<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6528 the function stack to the state it was in when the
6529 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6530 executed. This is useful for implementing language features like scoped
6531 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6532
6533<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6534<p>See the description
6535 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6536
6537</div>
6538
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6539<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6540<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6541 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6542</h4>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6543
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6544<div>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6545
6546<h5>Syntax:</h5>
6547<pre>
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6548 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]6549</pre>
6550
6551<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6552<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6553 insert a prefetch instruction if supported; otherwise, it is a noop.
6554 Prefetches have no effect on the behavior of the program but can change its
6555 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6556
6557<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6558<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6559 specifier determining if the fetch should be for a read (0) or write (1),
6560 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6561 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6562 specifies whether the prefetch is performed on the data (1) or instruction (0)
6563 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6564 must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6565
6566<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6567<p>This intrinsic does not modify the behavior of the program. In particular,
6568 prefetches cannot trap and do not produce a value. On targets that support
6569 this intrinsic, the prefetch can provide hints to the processor cache for
6570 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6571
6572</div>
6573
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6574<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6575<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6576 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6577</h4>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6578
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6579<div>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6580
6581<h5>Syntax:</h5>
6582<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6583 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6584</pre>
6585
6586<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6587<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6588 Counter (PC) in a region of code to simulators and other tools. The method
6589 is target specific, but it is expected that the marker will use exported
6590 symbols to transmit the PC of the marker. The marker makes no guarantees
6591 that it will remain with any specific instruction after optimizations. It is
6592 possible that the presence of a marker will inhibit optimizations. The
6593 intended use is to be inserted after optimizations to allow correlations of
6594 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6595
6596<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6597<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6598
6599<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6600<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6601 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6602
6603</div>
6604
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6605<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6606<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6607 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6608</h4>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6609
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6610<div>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6611
6612<h5>Syntax:</h5>
6613<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]6614 declare i64 @llvm.readcyclecounter()
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6615</pre>
6616
6617<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6618<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6619 counter register (or similar low latency, high accuracy clocks) on those
6620 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6621 should map to RPCC. As the backing counters overflow quickly (on the order
6622 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6623
6624<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6625<p>When directly supported, reading the cycle counter should not modify any
6626 memory. Implementations are allowed to either return a application specific
6627 value or a system wide value. On backends without support, this is lowered
6628 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6629
6630</div>
6631
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6632</div>
6633
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6634<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6635<h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6636 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6637</h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6638
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6639<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6640
6641<p>LLVM provides intrinsics for a few important standard C library functions.
6642 These intrinsics allow source-language front-ends to pass information about
6643 the alignment of the pointer arguments to the code generator, providing
6644 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6645
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6646<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6647<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6648 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6649</h4>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6650
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6651<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6652
6653<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6654<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]6655 integer bit width and for different address spaces. Not all targets support
6656 all bit widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6657
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6658<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6659 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]6660 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6661 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]6662 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6663</pre>
6664
6665<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6666<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6667 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6668
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6669<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6670 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6671 and the pointers can be in specified address spaces.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6672
6673<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6674
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6675<p>The first argument is a pointer to the destination, the second is a pointer
6676 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6677 number of bytes to copy, the fourth argument is the alignment of the
6678 source and destination locations, and the fifth is a boolean indicating a
6679 volatile access.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6680
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6681<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]6682 then the caller guarantees that both the source and destination pointers are
6683 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6684
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6685<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6686 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6687 The detailed access behavior is not very cleanly specified and it is unwise
6688 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6689
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6690<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6691
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6692<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6693 source location to the destination location, which are not allowed to
6694 overlap. It copies "len" bytes of memory over. If the argument is known to
6695 be aligned to some boundary, this can be specified as the fourth argument,
6696 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6697
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6698</div>
6699
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6700<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6701<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6702 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6703</h4>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6704
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6705<div>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6706
6707<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6708<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]6709 width and for different address space. Not all targets support all bit
6710 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6711
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6712<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6713 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]6714 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6715 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]6716 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6717</pre>
6718
6719<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6720<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6721 source location to the destination location. It is similar to the
6722 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6723 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6724
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6725<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6726 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6727 and the pointers can be in specified address spaces.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6728
6729<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6730
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6731<p>The first argument is a pointer to the destination, the second is a pointer
6732 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6733 number of bytes to copy, the fourth argument is the alignment of the
6734 source and destination locations, and the fifth is a boolean indicating a
6735 volatile access.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6736
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6737<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]6738 then the caller guarantees that the source and destination pointers are
6739 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6740
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6741<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6742 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6743 The detailed access behavior is not very cleanly specified and it is unwise
6744 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6745
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6746<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6747
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6748<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6749 source location to the destination location, which may overlap. It copies
6750 "len" bytes of memory over. If the argument is known to be aligned to some
6751 boundary, this can be specified as the fourth argument, otherwise it should
6752 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6753
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6754</div>
6755
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6756<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6757<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6758 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6759</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6760
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6761<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6762
6763<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6764<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]6765 width and for different address spaces. However, not all targets support all
6766 bit widths.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6767
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6768<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6769 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6770 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6771 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6772 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6773</pre>
6774
6775<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6776<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6777 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6778
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6779<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6780 intrinsic does not return a value and takes extra alignment/volatile
6781 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6782
6783<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6784<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]6785 byte value with which to fill it, the third argument is an integer argument
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6786 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6787 alignment of the destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6788
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6789<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]6790 then the caller guarantees that the destination pointer is aligned to that
6791 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6792
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6793<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6794 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6795 The detailed access behavior is not very cleanly specified and it is unwise
6796 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6797
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6798<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6799<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6800 at the destination location. If the argument is known to be aligned to some
6801 boundary, this can be specified as the fourth argument, otherwise it should
6802 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6803
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6804</div>
6805
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6806<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6807<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6808 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6809</h4>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6810
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6811<div>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6812
6813<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6814<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6815 floating point or vector of floating point type. Not all targets support all
6816 types however.</p>
6817
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6818<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6819 declare float @llvm.sqrt.f32(float %Val)
6820 declare double @llvm.sqrt.f64(double %Val)
6821 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6822 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6823 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6824</pre>
6825
6826<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6827<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6828 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6829 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6830 behavior for negative numbers other than -0.0 (which allows for better
6831 optimization, because there is no need to worry about errno being
6832 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]6833
6834<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6835<p>The argument and return value are floating point numbers of the same
6836 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6837
6838<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6839<p>This function returns the sqrt of the specified operand if it is a
6840 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6841
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6842</div>
6843
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6844<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6845<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6846 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6847</h4>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6848
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6849<div>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6850
6851<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6852<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6853 floating point or vector of floating point type. Not all targets support all
6854 types however.</p>
6855
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6856<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6857 declare float @llvm.powi.f32(float %Val, i32 %power)
6858 declare double @llvm.powi.f64(double %Val, i32 %power)
6859 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6860 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6861 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6862</pre>
6863
6864<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6865<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6866 specified (positive or negative) power. The order of evaluation of
6867 multiplications is not defined. When a vector of floating point type is
6868 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6869
6870<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6871<p>The second argument is an integer power, and the first is a value to raise to
6872 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6873
6874<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6875<p>This function returns the first value raised to the second power with an
6876 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6877
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6878</div>
6879
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6880<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6881<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6882 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6883</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6884
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6885<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6886
6887<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6888<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6889 floating point or vector of floating point type. Not all targets support all
6890 types however.</p>
6891
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6892<pre>
6893 declare float @llvm.sin.f32(float %Val)
6894 declare double @llvm.sin.f64(double %Val)
6895 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6896 declare fp128 @llvm.sin.f128(fp128 %Val)
6897 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6898</pre>
6899
6900<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6901<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6902
6903<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6904<p>The argument and return value are floating point numbers of the same
6905 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6906
6907<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6908<p>This function returns the sine of the specified operand, returning the same
6909 values as the libm <tt>sin</tt> functions would, and handles error conditions
6910 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6911
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6912</div>
6913
6914<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6915<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6916 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6917</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6918
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6919<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6920
6921<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6922<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6923 floating point or vector of floating point type. Not all targets support all
6924 types however.</p>
6925
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6926<pre>
6927 declare float @llvm.cos.f32(float %Val)
6928 declare double @llvm.cos.f64(double %Val)
6929 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6930 declare fp128 @llvm.cos.f128(fp128 %Val)
6931 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6932</pre>
6933
6934<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6935<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6936
6937<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6938<p>The argument and return value are floating point numbers of the same
6939 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6940
6941<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6942<p>This function returns the cosine of the specified operand, returning the same
6943 values as the libm <tt>cos</tt> functions would, and handles error conditions
6944 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6945
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6946</div>
6947
6948<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6949<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6950 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6951</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6952
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6953<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6954
6955<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6956<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6957 floating point or vector of floating point type. Not all targets support all
6958 types however.</p>
6959
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6960<pre>
6961 declare float @llvm.pow.f32(float %Val, float %Power)
6962 declare double @llvm.pow.f64(double %Val, double %Power)
6963 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6964 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6965 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6966</pre>
6967
6968<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6969<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6970 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6971
6972<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6973<p>The second argument is a floating point power, and the first is a value to
6974 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6975
6976<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6977<p>This function returns the first value raised to the second power, returning
6978 the same values as the libm <tt>pow</tt> functions would, and handles error
6979 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6980
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6981</div>
6982
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6983</div>
6984
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]6985<!-- _______________________________________________________________________ -->
6986<h4>
6987 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6988</h4>
6989
6990<div>
6991
6992<h5>Syntax:</h5>
6993<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6994 floating point or vector of floating point type. Not all targets support all
6995 types however.</p>
6996
6997<pre>
6998 declare float @llvm.exp.f32(float %Val)
6999 declare double @llvm.exp.f64(double %Val)
7000 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
7001 declare fp128 @llvm.exp.f128(fp128 %Val)
7002 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
7003</pre>
7004
7005<h5>Overview:</h5>
7006<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
7007
7008<h5>Arguments:</h5>
7009<p>The argument and return value are floating point numbers of the same
7010 type.</p>
7011
7012<h5>Semantics:</h5>
7013<p>This function returns the same values as the libm <tt>exp</tt> functions
7014 would, and handles error conditions in the same way.</p>
7015
7016</div>
7017
7018<!-- _______________________________________________________________________ -->
7019<h4>
7020 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
7021</h4>
7022
7023<div>
7024
7025<h5>Syntax:</h5>
7026<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
7027 floating point or vector of floating point type. Not all targets support all
7028 types however.</p>
7029
7030<pre>
7031 declare float @llvm.log.f32(float %Val)
7032 declare double @llvm.log.f64(double %Val)
7033 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
7034 declare fp128 @llvm.log.f128(fp128 %Val)
7035 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
7036</pre>
7037
7038<h5>Overview:</h5>
7039<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
7040
7041<h5>Arguments:</h5>
7042<p>The argument and return value are floating point numbers of the same
7043 type.</p>
7044
7045<h5>Semantics:</h5>
7046<p>This function returns the same values as the libm <tt>log</tt> functions
7047 would, and handles error conditions in the same way.</p>
7048
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]7049<h4>
7050 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
7051</h4>
7052
7053<div>
7054
7055<h5>Syntax:</h5>
7056<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
7057 floating point or vector of floating point type. Not all targets support all
7058 types however.</p>
7059
7060<pre>
7061 declare float @llvm.fma.f32(float %a, float %b, float %c)
7062 declare double @llvm.fma.f64(double %a, double %b, double %c)
7063 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
7064 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
7065 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
7066</pre>
7067
7068<h5>Overview:</h5>
Cameron Zwarichabc43e62011-07-08 22:13:55 +0000[diff] [blame]7069<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]7070 operation.</p>
7071
7072<h5>Arguments:</h5>
7073<p>The argument and return value are floating point numbers of the same
7074 type.</p>
7075
7076<h5>Semantics:</h5>
7077<p>This function returns the same values as the libm <tt>fma</tt> functions
7078 would.</p>
7079
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]7080</div>
7081
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7082<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7083<h3>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7084 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7085</h3>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7086
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7087<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7088
7089<p>LLVM provides intrinsics for a few important bit manipulation operations.
7090 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7091
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7092<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7093<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]7094 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7095</h4>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7096
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7097<div>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7098
7099<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]7100<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7101 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
7102
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7103<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7104 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
7105 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
7106 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7107</pre>
7108
7109<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7110<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
7111 values with an even number of bytes (positive multiple of 16 bits). These
7112 are useful for performing operations on data that is not in the target's
7113 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7114
7115<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7116<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
7117 and low byte of the input i16 swapped. Similarly,
7118 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
7119 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
7120 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
7121 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
7122 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
7123 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7124
7125</div>
7126
7127<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7128<h4>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]7129 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7130</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7131
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7132<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7133
7134<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]7135<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]7136 width, or on any vector with integer elements. Not all targets support all
7137 bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7138
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7139<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7140 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7141 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7142 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7143 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
7144 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7145 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]7146</pre>
7147
7148<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7149<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
7150 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7151
7152<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7153<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]7154 integer type, or a vector with integer elements.
7155 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7156
7157<h5>Semantics:</h5>
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7158<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
7159 element of a vector.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7160
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7161</div>
7162
7163<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7164<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]7165 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7166</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7167
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7168<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7169
7170<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7171<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]7172 integer bit width, or any vector whose elements are integers. Not all
7173 targets support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7174
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7175<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7176 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
7177 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7178 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7179 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
7180 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7181 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]7182</pre>
7183
7184<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7185<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
7186 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7187
7188<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7189<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]7190 integer type, or any vector type with integer element type.
7191 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7192
7193<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7194<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7195 zeros in a variable, or within each element of the vector if the operation
7196 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]7197 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7198
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7199</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]7200
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7201<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7202<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]7203 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7204</h4>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7205
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7206<div>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7207
7208<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7209<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]7210 integer bit width, or any vector of integer elements. Not all targets
7211 support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7212
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7213<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7214 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
7215 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7216 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7217 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
7218 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7219 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]7220</pre>
7221
7222<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7223<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
7224 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7225
7226<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7227<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]7228 integer type, or a vectory with integer element type.. The return type
7229 must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7230
7231<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7232<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7233 zeros in a variable, or within each element of a vector.
7234 If the src == 0 then the result is the size in bits of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7235 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7236
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7237</div>
7238
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7239</div>
7240
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7241<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7242<h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7243 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7244</h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7245
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7246<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7247
7248<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7249
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7250<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7251<h4>
7252 <a name="int_sadd_overflow">
7253 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
7254 </a>
7255</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7256
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7257<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7258
7259<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7260<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]7261 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7262
7263<pre>
7264 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
7265 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7266 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
7267</pre>
7268
7269<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7270<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7271 a signed addition of the two arguments, and indicate whether an overflow
7272 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7273
7274<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7275<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]7276 be of integer types of any bit width, but they must have the same bit
7277 width. The second element of the result structure must be of
7278 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7279 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7280
7281<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7282<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7283 a signed addition of the two variables. They return a structure &mdash; the
7284 first element of which is the signed summation, and the second element of
7285 which is a bit specifying if the signed summation resulted in an
7286 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7287
7288<h5>Examples:</h5>
7289<pre>
7290 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7291 %sum = extractvalue {i32, i1} %res, 0
7292 %obit = extractvalue {i32, i1} %res, 1
7293 br i1 %obit, label %overflow, label %normal
7294</pre>
7295
7296</div>
7297
7298<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7299<h4>
7300 <a name="int_uadd_overflow">
7301 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
7302 </a>
7303</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7304
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7305<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7306
7307<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7308<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]7309 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7310
7311<pre>
7312 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
7313 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7314 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
7315</pre>
7316
7317<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7318<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7319 an unsigned addition of the two arguments, and indicate whether a carry
7320 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7321
7322<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7323<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]7324 be of integer types of any bit width, but they must have the same bit
7325 width. The second element of the result structure must be of
7326 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7327 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7328
7329<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7330<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7331 an unsigned addition of the two arguments. They return a structure &mdash;
7332 the first element of which is the sum, and the second element of which is a
7333 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7334
7335<h5>Examples:</h5>
7336<pre>
7337 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7338 %sum = extractvalue {i32, i1} %res, 0
7339 %obit = extractvalue {i32, i1} %res, 1
7340 br i1 %obit, label %carry, label %normal
7341</pre>
7342
7343</div>
7344
7345<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7346<h4>
7347 <a name="int_ssub_overflow">
7348 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
7349 </a>
7350</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7351
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7352<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7353
7354<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7355<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]7356 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7357
7358<pre>
7359 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
7360 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7361 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
7362</pre>
7363
7364<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7365<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7366 a signed subtraction of the two arguments, and indicate whether an overflow
7367 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7368
7369<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7370<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]7371 be of integer types of any bit width, but they must have the same bit
7372 width. The second element of the result structure must be of
7373 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7374 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7375
7376<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7377<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7378 a signed subtraction of the two arguments. They return a structure &mdash;
7379 the first element of which is the subtraction, and the second element of
7380 which is a bit specifying if the signed subtraction resulted in an
7381 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7382
7383<h5>Examples:</h5>
7384<pre>
7385 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7386 %sum = extractvalue {i32, i1} %res, 0
7387 %obit = extractvalue {i32, i1} %res, 1
7388 br i1 %obit, label %overflow, label %normal
7389</pre>
7390
7391</div>
7392
7393<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7394<h4>
7395 <a name="int_usub_overflow">
7396 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
7397 </a>
7398</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7399
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7400<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7401
7402<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7403<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]7404 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7405
7406<pre>
7407 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
7408 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7409 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
7410</pre>
7411
7412<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7413<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7414 an unsigned subtraction of the two arguments, and indicate whether an
7415 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7416
7417<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7418<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]7419 be of integer types of any bit width, but they must have the same bit
7420 width. The second element of the result structure must be of
7421 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7422 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7423
7424<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7425<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7426 an unsigned subtraction of the two arguments. They return a structure &mdash;
7427 the first element of which is the subtraction, and the second element of
7428 which is a bit specifying if the unsigned subtraction resulted in an
7429 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7430
7431<h5>Examples:</h5>
7432<pre>
7433 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7434 %sum = extractvalue {i32, i1} %res, 0
7435 %obit = extractvalue {i32, i1} %res, 1
7436 br i1 %obit, label %overflow, label %normal
7437</pre>
7438
7439</div>
7440
7441<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7442<h4>
7443 <a name="int_smul_overflow">
7444 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
7445 </a>
7446</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7447
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7448<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7449
7450<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7451<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]7452 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7453
7454<pre>
7455 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
7456 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7457 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
7458</pre>
7459
7460<h5>Overview:</h5>
7461
7462<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7463 a signed multiplication of the two arguments, and indicate whether an
7464 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7465
7466<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7467<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]7468 be of integer types of any bit width, but they must have the same bit
7469 width. The second element of the result structure must be of
7470 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7471 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7472
7473<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7474<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7475 a signed multiplication of the two arguments. They return a structure &mdash;
7476 the first element of which is the multiplication, and the second element of
7477 which is a bit specifying if the signed multiplication resulted in an
7478 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7479
7480<h5>Examples:</h5>
7481<pre>
7482 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7483 %sum = extractvalue {i32, i1} %res, 0
7484 %obit = extractvalue {i32, i1} %res, 1
7485 br i1 %obit, label %overflow, label %normal
7486</pre>
7487
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]7488</div>
7489
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7490<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7491<h4>
7492 <a name="int_umul_overflow">
7493 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7494 </a>
7495</h4>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7496
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7497<div>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7498
7499<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7500<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]7501 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7502
7503<pre>
7504 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7505 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7506 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7507</pre>
7508
7509<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7510<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7511 a unsigned multiplication of the two arguments, and indicate whether an
7512 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7513
7514<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7515<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]7516 be of integer types of any bit width, but they must have the same bit
7517 width. The second element of the result structure must be of
7518 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7519 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7520
7521<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7522<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7523 an unsigned multiplication of the two arguments. They return a structure
7524 &mdash; the first element of which is the multiplication, and the second
7525 element of which is a bit specifying if the unsigned multiplication resulted
7526 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7527
7528<h5>Examples:</h5>
7529<pre>
7530 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7531 %sum = extractvalue {i32, i1} %res, 0
7532 %obit = extractvalue {i32, i1} %res, 1
7533 br i1 %obit, label %overflow, label %normal
7534</pre>
7535
7536</div>
7537
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7538</div>
7539
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7540<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7541<h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7542 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7543</h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7544
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7545<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7546
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7547<p>Half precision floating point is a storage-only format. This means that it is
7548 a dense encoding (in memory) but does not support computation in the
7549 format.</p>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7550
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7551<p>This means that code must first load the half-precision floating point
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7552 value as an i16, then convert it to float with <a
7553 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7554 Computation can then be performed on the float value (including extending to
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7555 double etc). To store the value back to memory, it is first converted to
7556 float if needed, then converted to i16 with
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7557 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7558 storing as an i16 value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7559
7560<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7561<h4>
7562 <a name="int_convert_to_fp16">
7563 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7564 </a>
7565</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7566
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7567<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7568
7569<h5>Syntax:</h5>
7570<pre>
7571 declare i16 @llvm.convert.to.fp16(f32 %a)
7572</pre>
7573
7574<h5>Overview:</h5>
7575<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7576 a conversion from single precision floating point format to half precision
7577 floating point format.</p>
7578
7579<h5>Arguments:</h5>
7580<p>The intrinsic function contains single argument - the value to be
7581 converted.</p>
7582
7583<h5>Semantics:</h5>
7584<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7585 a conversion from single precision floating point format to half precision
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7586 floating point format. The return value is an <tt>i16</tt> which
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7587 contains the converted number.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7588
7589<h5>Examples:</h5>
7590<pre>
7591 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7592 store i16 %res, i16* @x, align 2
7593</pre>
7594
7595</div>
7596
7597<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7598<h4>
7599 <a name="int_convert_from_fp16">
7600 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7601 </a>
7602</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7603
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7604<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7605
7606<h5>Syntax:</h5>
7607<pre>
7608 declare f32 @llvm.convert.from.fp16(i16 %a)
7609</pre>
7610
7611<h5>Overview:</h5>
7612<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7613 a conversion from half precision floating point format to single precision
7614 floating point format.</p>
7615
7616<h5>Arguments:</h5>
7617<p>The intrinsic function contains single argument - the value to be
7618 converted.</p>
7619
7620<h5>Semantics:</h5>
7621<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7622 conversion from half single precision floating point format to single
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7623 precision floating point format. The input half-float value is represented by
7624 an <tt>i16</tt> value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7625
7626<h5>Examples:</h5>
7627<pre>
7628 %a = load i16* @x, align 2
7629 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7630</pre>
7631
7632</div>
7633
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7634</div>
7635
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7636<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7637<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7638 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7639</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7640
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7641<div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7642
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7643<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7644 prefix), are described in
7645 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7646 Level Debugging</a> document.</p>
7647
7648</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7649
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7650<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7651<h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7652 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7653</h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7654
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7655<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7656
7657<p>The LLVM exception handling intrinsics (which all start with
7658 <tt>llvm.eh.</tt> prefix), are described in
7659 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7660 Handling</a> document.</p>
7661
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7662</div>
7663
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7664<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7665<h3>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7666 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7667</h3>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7668
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7669<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7670
7671<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]7672 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7673 The result is a callable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7674 function pointer lacking the nest parameter - the caller does not need to
7675 provide a value for it. Instead, the value to use is stored in advance in a
7676 "trampoline", a block of memory usually allocated on the stack, which also
7677 contains code to splice the nest value into the argument list. This is used
7678 to implement the GCC nested function address extension.</p>
7679
7680<p>For example, if the function is
7681 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7682 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7683 follows:</p>
7684
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]7685<pre class="doc_code">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7686 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7687 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7688 %p = call i8* @llvm.init.trampoline(i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval)
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7689 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7690</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7691
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7692<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7693 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7694
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7695<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7696<h4>
7697 <a name="int_it">
7698 '<tt>llvm.init.trampoline</tt>' Intrinsic
7699 </a>
7700</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7701
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7702<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7703
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7704<h5>Syntax:</h5>
7705<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7706 declare i8* @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]7707</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7708
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7709<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7710<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7711 function pointer suitable for executing it.</p>
7712
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7713<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7714<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7715 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7716 sufficiently aligned block of memory; this memory is written to by the
7717 intrinsic. Note that the size and the alignment are target-specific - LLVM
7718 currently provides no portable way of determining them, so a front-end that
7719 generates this intrinsic needs to have some target-specific knowledge.
7720 The <tt>func</tt> argument must hold a function bitcast to
7721 an <tt>i8*</tt>.</p>
7722
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7723<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7724<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7725 dependent code, turning it into a function. A pointer to this function is
7726 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7727 function pointer type</a> before being called. The new function's signature
7728 is the same as that of <tt>func</tt> with any arguments marked with
7729 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7730 is allowed, and it must be of pointer type. Calling the new function is
7731 equivalent to calling <tt>func</tt> with the same argument list, but
7732 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7733 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7734 by <tt>tramp</tt> is modified, then the effect of any later call to the
7735 returned function pointer is undefined.</p>
7736
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7737</div>
7738
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7739</div>
7740
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7741<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7742<h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7743 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7744</h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7745
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7746<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7747
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7748<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7749 hardware constructs for atomic operations and memory synchronization. This
7750 provides an interface to the hardware, not an interface to the programmer. It
7751 is aimed at a low enough level to allow any programming models or APIs
7752 (Application Programming Interfaces) which need atomic behaviors to map
7753 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7754 hardware provides a "universal IR" for source languages, it also provides a
7755 starting point for developing a "universal" atomic operation and
7756 synchronization IR.</p>
7757
7758<p>These do <em>not</em> form an API such as high-level threading libraries,
7759 software transaction memory systems, atomic primitives, and intrinsic
7760 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7761 application libraries. The hardware interface provided by LLVM should allow
7762 a clean implementation of all of these APIs and parallel programming models.
7763 No one model or paradigm should be selected above others unless the hardware
7764 itself ubiquitously does so.</p>
7765
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7766<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7767<h4>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7768 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7769</h4>
7770
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7771<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7772<h5>Syntax:</h5>
7773<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7774 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]7775</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7776
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7777<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7778<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7779 specific pairs of memory access types.</p>
7780
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7781<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7782<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7783 The first four arguments enables a specific barrier as listed below. The
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]7784 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7785 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7786
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7787<ul>
7788 <li><tt>ll</tt>: load-load barrier</li>
7789 <li><tt>ls</tt>: load-store barrier</li>
7790 <li><tt>sl</tt>: store-load barrier</li>
7791 <li><tt>ss</tt>: store-store barrier</li>
7792 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7793</ul>
7794
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7795<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7796<p>This intrinsic causes the system to enforce some ordering constraints upon
7797 the loads and stores of the program. This barrier does not
7798 indicate <em>when</em> any events will occur, it only enforces
7799 an <em>order</em> in which they occur. For any of the specified pairs of load
7800 and store operations (f.ex. load-load, or store-load), all of the first
7801 operations preceding the barrier will complete before any of the second
7802 operations succeeding the barrier begin. Specifically the semantics for each
7803 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7804
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7805<ul>
7806 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7807 after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7808 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7809 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7810 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7811 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7812 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7813 load after the barrier begins.</li>
7814</ul>
7815
7816<p>These semantics are applied with a logical "and" behavior when more than one
7817 is enabled in a single memory barrier intrinsic.</p>
7818
7819<p>Backends may implement stronger barriers than those requested when they do
7820 not support as fine grained a barrier as requested. Some architectures do
7821 not need all types of barriers and on such architectures, these become
7822 noops.</p>
7823
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7824<h5>Example:</h5>
7825<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7826%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7827%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7828 store i32 4, %ptr
7829
7830%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0b0669a2011-06-29 17:14:00 +0000[diff] [blame]7831 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]7832 <i>; guarantee the above finishes</i>
7833 store i32 8, %ptr <i>; before this begins</i>
7834</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7835
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7836</div>
7837
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7838<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7839<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7840 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7841</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7842
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7843<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7844
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7845<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7846<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7847 any integer bit width and for different address spaces. Not all targets
7848 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7849
7850<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7851 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7852 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7853 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7854 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]7855</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7856
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7857<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7858<p>This loads a value in memory and compares it to a given value. If they are
7859 equal, it stores a new value into the memory.</p>
7860
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7861<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7862<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7863 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7864 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7865 this integer type. While any bit width integer may be used, targets may only
7866 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7867
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7868<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7869<p>This entire intrinsic must be executed atomically. It first loads the value
7870 in memory pointed to by <tt>ptr</tt> and compares it with the
7871 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7872 memory. The loaded value is yielded in all cases. This provides the
7873 equivalent of an atomic compare-and-swap operation within the SSA
7874 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7875
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7876<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7877<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7878%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7879%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7880 store i32 4, %ptr
7881
7882%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7883%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7884 <i>; yields {i32}:result1 = 4</i>
7885%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7886%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7887
7888%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7889%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7890 <i>; yields {i32}:result2 = 8</i>
7891%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7892
7893%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7894</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7895
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7896</div>
7897
7898<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7899<h4>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7900 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7901</h4>
7902
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7903<div>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7904<h5>Syntax:</h5>
7905
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7906<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7907 integer bit width. Not all targets support all bit widths however.</p>
7908
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7909<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7910 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7911 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7912 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7913 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]7914</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7915
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7916<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7917<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7918 the value from memory. It then stores the value in <tt>val</tt> in the memory
7919 at <tt>ptr</tt>.</p>
7920
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7921<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7922<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7923 the <tt>val</tt> argument and the result must be integers of the same bit
7924 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7925 integer type. The targets may only lower integer representations they
7926 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7927
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7928<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7929<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7930 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7931 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7932
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7933<h5>Examples:</h5>
7934<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7935%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7936%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7937 store i32 4, %ptr
7938
7939%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7940%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7941 <i>; yields {i32}:result1 = 4</i>
7942%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7943%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7944
7945%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7946%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7947 <i>; yields {i32}:result2 = 8</i>
7948
7949%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7950%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7951</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7952
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7953</div>
7954
7955<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7956<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7957 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7958</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7959
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7960<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7961
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7962<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7963<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7964 any integer bit width. Not all targets support all bit widths however.</p>
7965
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7966<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7967 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7968 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7969 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7970 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]7971</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7972
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7973<h5>Overview:</h5>
7974<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7975 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7976
7977<h5>Arguments:</h5>
7978<p>The intrinsic takes two arguments, the first a pointer to an integer value
7979 and the second an integer value. The result is also an integer value. These
7980 integer types can have any bit width, but they must all have the same bit
7981 width. The targets may only lower integer representations they support.</p>
7982
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7983<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7984<p>This intrinsic does a series of operations atomically. It first loads the
7985 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7986 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]7987
7988<h5>Examples:</h5>
7989<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7990%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7991%ptr = bitcast i8* %mallocP to i32*
7992 store i32 4, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7993%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7994 <i>; yields {i32}:result1 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7995%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7996 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7997%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7998 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7999%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]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
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]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_sub">'<tt>llvm.atomic.load.sub.*</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
Mon P Wang28873102008-06-25 08:15:39 +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.sub</tt> on
8013 any integer bit width and for different address spaces. Not all targets
8014 support all bit widths however.</p>
8015
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8016<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8017 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8018 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8019 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8020 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]8021</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8022
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8023<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]8024<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8025 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
8026
8027<h5>Arguments:</h5>
8028<p>The intrinsic takes two arguments, the first a pointer to an integer value
8029 and the second an integer value. The result is also an integer value. These
8030 integer types can have any bit width, but they must all have the same bit
8031 width. The targets may only lower integer representations they support.</p>
8032
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8033<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8034<p>This intrinsic does a series of operations atomically. It first loads the
8035 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
8036 result to <tt>ptr</tt>. It yields the original value stored
8037 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8038
8039<h5>Examples:</h5>
8040<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]8041%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8042%ptr = bitcast i8* %mallocP to i32*
8043 store i32 8, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8044%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8045 <i>; yields {i32}:result1 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8046%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8047 <i>; yields {i32}:result2 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8048%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8049 <i>; yields {i32}:result3 = 2</i>
8050%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
8051</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8052
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8053</div>
8054
8055<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8056<h4>
8057 <a name="int_atomic_load_and">
8058 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
8059 </a>
8060 <br>
8061 <a name="int_atomic_load_nand">
8062 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
8063 </a>
8064 <br>
8065 <a name="int_atomic_load_or">
8066 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
8067 </a>
8068 <br>
8069 <a name="int_atomic_load_xor">
8070 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
8071 </a>
8072</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8073
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8074<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8075
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8076<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8077<p>These are overloaded intrinsics. You can
8078 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
8079 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
8080 bit width and for different address spaces. Not all targets support all bit
8081 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8082
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8083<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8084 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8085 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8086 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8087 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]8088</pre>
8089
8090<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8091 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8092 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8093 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8094 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]8095</pre>
8096
8097<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8098 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8099 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8100 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8101 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]8102</pre>
8103
8104<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8105 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8106 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8107 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8108 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]8109</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8110
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8111<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8112<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
8113 the value stored in memory at <tt>ptr</tt>. It yields the original value
8114 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8115
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8116<h5>Arguments:</h5>
8117<p>These intrinsics take two arguments, the first a pointer to an integer value
8118 and the second an integer value. The result is also an integer value. These
8119 integer types can have any bit width, but they must all have the same bit
8120 width. The targets may only lower integer representations they support.</p>
8121
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8122<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8123<p>These intrinsics does a series of operations atomically. They first load the
8124 value stored at <tt>ptr</tt>. They then do the bitwise
8125 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
8126 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8127
8128<h5>Examples:</h5>
8129<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]8130%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8131%ptr = bitcast i8* %mallocP to i32*
8132 store i32 0x0F0F, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8133%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8134 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8135%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8136 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8137%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8138 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8139%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8140 <i>; yields {i32}:result3 = FF</i>
8141%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
8142</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8143
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8144</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8145
8146<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8147<h4>
8148 <a name="int_atomic_load_max">
8149 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
8150 </a>
8151 <br>
8152 <a name="int_atomic_load_min">
8153 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
8154 </a>
8155 <br>
8156 <a name="int_atomic_load_umax">
8157 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
8158 </a>
8159 <br>
8160 <a name="int_atomic_load_umin">
8161 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
8162 </a>
8163</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8164
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8165<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8166
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8167<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8168<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
8169 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
8170 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
8171 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8172
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8173<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8174 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8175 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8176 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8177 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]8178</pre>
8179
8180<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8181 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8182 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8183 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8184 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]8185</pre>
8186
8187<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8188 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8189 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8190 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8191 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]8192</pre>
8193
8194<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8195 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8196 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8197 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8198 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]8199</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8200
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8201<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]8202<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8203 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
8204 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8205
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8206<h5>Arguments:</h5>
8207<p>These intrinsics take two arguments, the first a pointer to an integer value
8208 and the second an integer value. The result is also an integer value. These
8209 integer types can have any bit width, but they must all have the same bit
8210 width. The targets may only lower integer representations they support.</p>
8211
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8212<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8213<p>These intrinsics does a series of operations atomically. They first load the
8214 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
8215 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
8216 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8217
8218<h5>Examples:</h5>
8219<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]8220%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8221%ptr = bitcast i8* %mallocP to i32*
8222 store i32 7, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8223%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8224 <i>; yields {i32}:result0 = 7</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8225%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8226 <i>; yields {i32}:result1 = -2</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8227%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8228 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8229%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8230 <i>; yields {i32}:result3 = 8</i>
8231%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
8232</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8233
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8234</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]8235
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8236</div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8237
8238<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8239<h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8240 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8241</h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8242
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8243<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8244
8245<p>This class of intrinsics exists to information about the lifetime of memory
8246 objects and ranges where variables are immutable.</p>
8247
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8248<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8249<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8250 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8251</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8252
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8253<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8254
8255<h5>Syntax:</h5>
8256<pre>
8257 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8258</pre>
8259
8260<h5>Overview:</h5>
8261<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
8262 object's lifetime.</p>
8263
8264<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8265<p>The first argument is a constant integer representing the size of the
8266 object, or -1 if it is variable sized. The second argument is a pointer to
8267 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8268
8269<h5>Semantics:</h5>
8270<p>This intrinsic indicates that before this point in the code, the value of the
8271 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]8272 never be used and has an undefined value. A load from the pointer that
8273 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8274 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
8275
8276</div>
8277
8278<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8279<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8280 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8281</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8282
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8283<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8284
8285<h5>Syntax:</h5>
8286<pre>
8287 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8288</pre>
8289
8290<h5>Overview:</h5>
8291<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
8292 object's lifetime.</p>
8293
8294<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8295<p>The first argument is a constant integer representing the size of the
8296 object, or -1 if it is variable sized. The second argument is a pointer to
8297 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8298
8299<h5>Semantics:</h5>
8300<p>This intrinsic indicates that after this point in the code, the value of the
8301 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
8302 never be used and has an undefined value. Any stores into the memory object
8303 following this intrinsic may be removed as dead.
8304
8305</div>
8306
8307<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8308<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8309 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8310</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8311
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8312<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8313
8314<h5>Syntax:</h5>
8315<pre>
Nick Lewycky29b6cb42010-11-30 04:13:41 +0000[diff] [blame]8316 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8317</pre>
8318
8319<h5>Overview:</h5>
8320<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
8321 a memory object will not change.</p>
8322
8323<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8324<p>The first argument is a constant integer representing the size of the
8325 object, or -1 if it is variable sized. The second argument is a pointer to
8326 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8327
8328<h5>Semantics:</h5>
8329<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
8330 the return value, the referenced memory location is constant and
8331 unchanging.</p>
8332
8333</div>
8334
8335<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8336<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8337 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8338</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8339
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8340<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8341
8342<h5>Syntax:</h5>
8343<pre>
8344 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8345</pre>
8346
8347<h5>Overview:</h5>
8348<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
8349 a memory object are mutable.</p>
8350
8351<h5>Arguments:</h5>
8352<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8353 The second argument is a constant integer representing the size of the
8354 object, or -1 if it is variable sized and the third argument is a pointer
8355 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8356
8357<h5>Semantics:</h5>
8358<p>This intrinsic indicates that the memory is mutable again.</p>
8359
8360</div>
8361
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8362</div>
8363
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]8364<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8365<h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8366 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8367</h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8368
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8369<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8370
8371<p>This class of intrinsics is designed to be generic and has no specific
8372 purpose.</p>
8373
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8374<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8375<h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8376 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8377</h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8378
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8379<div>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8380
8381<h5>Syntax:</h5>
8382<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8383 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]8384</pre>
8385
8386<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8387<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8388
8389<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8390<p>The first argument is a pointer to a value, the second is a pointer to a
8391 global string, the third is a pointer to a global string which is the source
8392 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8393
8394<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8395<p>This intrinsic allows annotation of local variables with arbitrary strings.
8396 This can be useful for special purpose optimizations that want to look for
8397 these annotations. These have no other defined use, they are ignored by code
8398 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8399
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8400</div>
8401
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8402<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8403<h4>
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]8404 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8405</h4>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8406
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8407<div>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8408
8409<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8410<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
8411 any integer bit width.</p>
8412
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8413<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8414 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8415 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8416 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8417 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8418 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]8419</pre>
8420
8421<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8422<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8423
8424<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8425<p>The first argument is an integer value (result of some expression), the
8426 second is a pointer to a global string, the third is a pointer to a global
8427 string which is the source file name, and the last argument is the line
8428 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8429
8430<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8431<p>This intrinsic allows annotations to be put on arbitrary expressions with
8432 arbitrary strings. This can be useful for special purpose optimizations that
8433 want to look for these annotations. These have no other defined use, they
8434 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8435
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8436</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]8437
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8438<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8439<h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8440 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8441</h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8442
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8443<div>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8444
8445<h5>Syntax:</h5>
8446<pre>
8447 declare void @llvm.trap()
8448</pre>
8449
8450<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8451<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8452
8453<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8454<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8455
8456<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8457<p>This intrinsics is lowered to the target dependent trap instruction. If the
8458 target does not have a trap instruction, this intrinsic will be lowered to
8459 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8460
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8461</div>
8462
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8463<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8464<h4>
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]8465 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8466</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8467
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8468<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8469
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8470<h5>Syntax:</h5>
8471<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8472 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8473</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8474
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8475<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8476<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8477 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8478 ensure that it is placed on the stack before local variables.</p>
8479
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8480<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8481<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8482 arguments. The first argument is the value loaded from the stack
8483 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8484 that has enough space to hold the value of the guard.</p>
8485
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8486<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8487<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8488 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8489 stack. This is to ensure that if a local variable on the stack is
8490 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8491 the guard on the stack is checked against the original guard. If they are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8492 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8493 function.</p>
8494
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8495</div>
8496
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8497<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8498<h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8499 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8500</h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8501
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8502<div>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8503
8504<h5>Syntax:</h5>
8505<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8506 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8507 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8508</pre>
8509
8510<h5>Overview:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8511<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8512 the optimizers to determine at compile time whether a) an operation (like
8513 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8514 runtime check for overflow isn't necessary. An object in this context means
8515 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8516
8517<h5>Arguments:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8518<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]8519 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8520 is a boolean 0 or 1. This argument determines whether you want the
8521 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]8522 1, variables are not allowed.</p>
8523
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8524<h5>Semantics:</h5>
8525<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8526 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8527 depending on the <tt>type</tt> argument, if the size cannot be determined at
8528 compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8529
8530</div>
8531
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8532</div>
8533
8534</div>
8535
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8536<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8537<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8538<address>
8539 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]8540 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
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8544 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]8545 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8546 Last modified: $Date$
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Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]8549</body>
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