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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / ff03048c1350fcc4fda1ef6d6c57252f3a950854 / . / 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 Wendling772fe172011-07-27 20:18:04 +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>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]205 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]206 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]207 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]208 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]209 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]210 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]211 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
212 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]213 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
214 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
215 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]216 </ol>
217 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]218 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
219 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]220 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
221 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
222 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]223 </ol>
224 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]225 <li><a href="#int_codegen">Code Generator Intrinsics</a>
226 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]227 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
228 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
229 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
230 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
231 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
232 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohman31f1af12010-05-26 21:56:15 +0000[diff] [blame]233 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]234 </ol>
235 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]236 <li><a href="#int_libc">Standard C Library Intrinsics</a>
237 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]238 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
239 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
240 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
241 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
242 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]243 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
244 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
245 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohman08b280b2011-05-27 00:36:31 +0000[diff] [blame]246 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
247 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]248 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]249 </ol>
250 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]251 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]252 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]253 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]254 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
255 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
256 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]257 </ol>
258 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]259 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
260 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]261 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
262 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
263 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
264 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
265 <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]266 <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]267 </ol>
268 </li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]269 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
270 <ol>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]271 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
272 <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]273 </ol>
274 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]275 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]276 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]277 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]278 <ol>
279 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]280 </ol>
281 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]282 <li><a href="#int_atomics">Atomic intrinsics</a>
283 <ol>
284 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
285 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
286 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
287 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
288 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
289 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
290 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
291 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
292 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
293 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
294 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
295 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
296 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
297 </ol>
298 </li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]299 <li><a href="#int_memorymarkers">Memory Use Markers</a>
300 <ol>
301 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
302 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
303 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
304 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
305 </ol>
306 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]307 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]308 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]309 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]310 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]311 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]312 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]313 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]314 '<tt>llvm.trap</tt>' Intrinsic</a></li>
315 <li><a href="#int_stackprotector">
316 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]317 <li><a href="#int_objectsize">
318 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]319 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]320 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]321 </ol>
322 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]323</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]324
325<div class="doc_author">
326 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
327 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]328</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]329
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]330<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]331<h2><a name="abstract">Abstract</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]332<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]333
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]334<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]335
336<p>This document is a reference manual for the LLVM assembly language. LLVM is
337 a Static Single Assignment (SSA) based representation that provides type
338 safety, low-level operations, flexibility, and the capability of representing
339 'all' high-level languages cleanly. It is the common code representation
340 used throughout all phases of the LLVM compilation strategy.</p>
341
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]342</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]343
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]344<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]345<h2><a name="introduction">Introduction</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]346<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]347
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]348<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]349
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]350<p>The LLVM code representation is designed to be used in three different forms:
351 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
352 for fast loading by a Just-In-Time compiler), and as a human readable
353 assembly language representation. This allows LLVM to provide a powerful
354 intermediate representation for efficient compiler transformations and
355 analysis, while providing a natural means to debug and visualize the
356 transformations. The three different forms of LLVM are all equivalent. This
357 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]358
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]359<p>The LLVM representation aims to be light-weight and low-level while being
360 expressive, typed, and extensible at the same time. It aims to be a
361 "universal IR" of sorts, by being at a low enough level that high-level ideas
362 may be cleanly mapped to it (similar to how microprocessors are "universal
363 IR's", allowing many source languages to be mapped to them). By providing
364 type information, LLVM can be used as the target of optimizations: for
365 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]366 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]367 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]368
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]369<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]370<h4>
371 <a name="wellformed">Well-Formedness</a>
372</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]373
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]374<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]375
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]376<p>It is important to note that this document describes 'well formed' LLVM
377 assembly language. There is a difference between what the parser accepts and
378 what is considered 'well formed'. For example, the following instruction is
379 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]380
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]381<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]382%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]383</pre>
384
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]385<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
386 LLVM infrastructure provides a verification pass that may be used to verify
387 that an LLVM module is well formed. This pass is automatically run by the
388 parser after parsing input assembly and by the optimizer before it outputs
389 bitcode. The violations pointed out by the verifier pass indicate bugs in
390 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]391
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]392</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]393
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]394</div>
395
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]396<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]397
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]398<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]399<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]400<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]401
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]402<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]403
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]404<p>LLVM identifiers come in two basic types: global and local. Global
405 identifiers (functions, global variables) begin with the <tt>'@'</tt>
406 character. Local identifiers (register names, types) begin with
407 the <tt>'%'</tt> character. Additionally, there are three different formats
408 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]409
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]410<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]411 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]412 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
413 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
414 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
415 other characters in their names can be surrounded with quotes. Special
416 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
417 ASCII code for the character in hexadecimal. In this way, any character
418 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]419
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]420 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]421 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]422
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]423 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]424 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]425</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]426
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]427<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]428 don't need to worry about name clashes with reserved words, and the set of
429 reserved words may be expanded in the future without penalty. Additionally,
430 unnamed identifiers allow a compiler to quickly come up with a temporary
431 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]432
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]433<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]434 languages. There are keywords for different opcodes
435 ('<tt><a href="#i_add">add</a></tt>',
436 '<tt><a href="#i_bitcast">bitcast</a></tt>',
437 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
438 ('<tt><a href="#t_void">void</a></tt>',
439 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
440 reserved words cannot conflict with variable names, because none of them
441 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]442
443<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]444 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]445
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]446<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]447
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]448<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]449%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]450</pre>
451
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]452<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]453
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]454<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]455%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]456</pre>
457
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]458<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]459
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]460<pre class="doc_code">
Gabor Greifec58f752009-10-28 13:05:07 +0000[diff] [blame]461%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
462%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]463%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]464</pre>
465
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]466<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
467 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]468
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]469<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]470 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]471 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]472
473 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]474 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]475
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]476 <li>Unnamed temporaries are numbered sequentially</li>
477</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]478
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]479<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]480 demonstrating instructions, we will follow an instruction with a comment that
481 defines the type and name of value produced. Comments are shown in italic
482 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]483
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]484</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]485
486<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]487<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]488<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]489<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]490<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]491<h3>
492 <a name="modulestructure">Module Structure</a>
493</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]494
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]495<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]496
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]497<p>LLVM programs are composed of "Module"s, each of which is a translation unit
498 of the input programs. Each module consists of functions, global variables,
499 and symbol table entries. Modules may be combined together with the LLVM
500 linker, which merges function (and global variable) definitions, resolves
501 forward declarations, and merges symbol table entries. Here is an example of
502 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]503
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]504<pre class="doc_code">
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]505<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckydb9cd762011-01-29 01:09:53 +0000[diff] [blame]506<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]507
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]508<i>; External declaration of the puts function</i>&nbsp;
509<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]510
511<i>; Definition of main function</i>
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]512define i32 @main() { <i>; i32()* </i>&nbsp;
513 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
514 %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]515
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]516 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
517 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
518 <a href="#i_ret">ret</a> i32 0&nbsp;
519}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]520
521<i>; Named metadata</i>
522!1 = metadata !{i32 41}
523!foo = !{!1, null}
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]524</pre>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]525
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]526<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]527 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]528 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]529 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
530 "<tt>foo"</tt>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]531
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]532<p>In general, a module is made up of a list of global values, where both
533 functions and global variables are global values. Global values are
534 represented by a pointer to a memory location (in this case, a pointer to an
535 array of char, and a pointer to a function), and have one of the
536 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]537
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]538</div>
539
540<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]541<h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]542 <a name="linkage">Linkage Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]543</h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]544
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]545<div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]546
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]547<p>All Global Variables and Functions have one of the following types of
548 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]549
550<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]551 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]552 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
553 by objects in the current module. In particular, linking code into a
554 module with an private global value may cause the private to be renamed as
555 necessary to avoid collisions. Because the symbol is private to the
556 module, all references can be updated. This doesn't show up in any symbol
557 table in the object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]558
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]559 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]560 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
561 assembler and evaluated by the linker. Unlike normal strong symbols, they
562 are removed by the linker from the final linked image (executable or
563 dynamic library).</dd>
564
565 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
566 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
567 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
568 linker. The symbols are removed by the linker from the final linked image
569 (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]570
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]571 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
572 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
573 of the object is not taken. For instance, functions that had an inline
574 definition, but the compiler decided not to inline it. Note,
575 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
576 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
577 visibility. The symbols are removed by the linker from the final linked
578 image (executable or dynamic library).</dd>
579
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]580 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling07d31772010-06-29 22:34:52 +0000[diff] [blame]581 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]582 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
583 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]584
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]585 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]586 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]587 into the object file corresponding to the LLVM module. They exist to
588 allow inlining and other optimizations to take place given knowledge of
589 the definition of the global, which is known to be somewhere outside the
590 module. Globals with <tt>available_externally</tt> linkage are allowed to
591 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
592 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]593
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]594 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]595 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]596 the same name when linkage occurs. This can be used to implement
597 some forms of inline functions, templates, or other code which must be
598 generated in each translation unit that uses it, but where the body may
599 be overridden with a more definitive definition later. Unreferenced
600 <tt>linkonce</tt> globals are allowed to be discarded. Note that
601 <tt>linkonce</tt> linkage does not actually allow the optimizer to
602 inline the body of this function into callers because it doesn't know if
603 this definition of the function is the definitive definition within the
604 program or whether it will be overridden by a stronger definition.
605 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
606 linkage.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]607
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]608 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]609 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
610 <tt>linkonce</tt> linkage, except that unreferenced globals with
611 <tt>weak</tt> linkage may not be discarded. This is used for globals that
612 are declared "weak" in C source code.</dd>
613
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]614 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]615 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
616 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
617 global scope.
618 Symbols with "<tt>common</tt>" linkage are merged in the same way as
619 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]620 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]621 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]622 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
623 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]624
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]625
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]626 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]627 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]628 pointer to array type. When two global variables with appending linkage
629 are linked together, the two global arrays are appended together. This is
630 the LLVM, typesafe, equivalent of having the system linker append together
631 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]632
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]633 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]634 <dd>The semantics of this linkage follow the ELF object file model: the symbol
635 is weak until linked, if not linked, the symbol becomes null instead of
636 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]637
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]638 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
639 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]640 <dd>Some languages allow differing globals to be merged, such as two functions
641 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]642 that only equivalent globals are ever merged (the "one definition rule"
643 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]644 and <tt>weak_odr</tt> linkage types to indicate that the global will only
645 be merged with equivalent globals. These linkage types are otherwise the
646 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]647
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]648 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]649 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]650 visible, meaning that it participates in linkage and can be used to
651 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]652</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]653
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]654<p>The next two types of linkage are targeted for Microsoft Windows platform
655 only. They are designed to support importing (exporting) symbols from (to)
656 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]657
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]658<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]659 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]660 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]661 or variable via a global pointer to a pointer that is set up by the DLL
662 exporting the symbol. On Microsoft Windows targets, the pointer name is
663 formed by combining <code>__imp_</code> and the function or variable
664 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]665
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]666 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]667 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]668 pointer to a pointer in a DLL, so that it can be referenced with the
669 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
670 name is formed by combining <code>__imp_</code> and the function or
671 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]672</dl>
673
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]674<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
675 another module defined a "<tt>.LC0</tt>" variable and was linked with this
676 one, one of the two would be renamed, preventing a collision. Since
677 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
678 declarations), they are accessible outside of the current module.</p>
679
680<p>It is illegal for a function <i>declaration</i> to have any linkage type
681 other than "externally visible", <tt>dllimport</tt>
682 or <tt>extern_weak</tt>.</p>
683
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]684<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]685 or <tt>weak_odr</tt> linkages.</p>
686
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]687</div>
688
689<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]690<h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]691 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]692</h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]693
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]694<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]695
696<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]697 and <a href="#i_invoke">invokes</a> can all have an optional calling
698 convention specified for the call. The calling convention of any pair of
699 dynamic caller/callee must match, or the behavior of the program is
700 undefined. The following calling conventions are supported by LLVM, and more
701 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]702
703<dl>
704 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]705 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]706 specified) matches the target C calling conventions. This calling
707 convention supports varargs function calls and tolerates some mismatch in
708 the declared prototype and implemented declaration of the function (as
709 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]710
711 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]712 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]713 (e.g. by passing things in registers). This calling convention allows the
714 target to use whatever tricks it wants to produce fast code for the
715 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]716 (Application Binary Interface).
717 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]718 when this or the GHC convention is used.</a> This calling convention
719 does not support varargs and requires the prototype of all callees to
720 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]721
722 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]723 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]724 as possible under the assumption that the call is not commonly executed.
725 As such, these calls often preserve all registers so that the call does
726 not break any live ranges in the caller side. This calling convention
727 does not support varargs and requires the prototype of all callees to
728 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]729
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]730 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
731 <dd>This calling convention has been implemented specifically for use by the
732 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
733 It passes everything in registers, going to extremes to achieve this by
734 disabling callee save registers. This calling convention should not be
735 used lightly but only for specific situations such as an alternative to
736 the <em>register pinning</em> performance technique often used when
737 implementing functional programming languages.At the moment only X86
738 supports this convention and it has the following limitations:
739 <ul>
740 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
741 floating point types are supported.</li>
742 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
743 6 floating point parameters.</li>
744 </ul>
745 This calling convention supports
746 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
747 requires both the caller and callee are using it.
748 </dd>
749
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]750 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]751 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]752 target-specific calling conventions to be used. Target specific calling
753 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]754</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]755
756<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]757 support Pascal conventions or any other well-known target-independent
758 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]759
760</div>
761
762<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]763<h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]764 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]765</h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]766
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]767<div>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]768
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]769<p>All Global Variables and Functions have one of the following visibility
770 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]771
772<dl>
773 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]774 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]775 that the declaration is visible to other modules and, in shared libraries,
776 means that the declared entity may be overridden. On Darwin, default
777 visibility means that the declaration is visible to other modules. Default
778 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]779
780 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]781 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]782 object if they are in the same shared object. Usually, hidden visibility
783 indicates that the symbol will not be placed into the dynamic symbol
784 table, so no other module (executable or shared library) can reference it
785 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]786
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]787 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]788 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]789 the dynamic symbol table, but that references within the defining module
790 will bind to the local symbol. That is, the symbol cannot be overridden by
791 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]792</dl>
793
794</div>
795
796<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]797<h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]798 <a name="namedtypes">Named Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]799</h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]800
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]801<div>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]802
803<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]804 it easier to read the IR and make the IR more condensed (particularly when
805 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]806
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]807<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]808%mytype = type { %mytype*, i32 }
809</pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]810
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]811<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattnerdc65f222010-08-17 23:26:04 +0000[diff] [blame]812 "<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]813 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]814
815<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]816 and that you can therefore specify multiple names for the same type. This
817 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
818 uses structural typing, the name is not part of the type. When printing out
819 LLVM IR, the printer will pick <em>one name</em> to render all types of a
820 particular shape. This means that if you have code where two different
821 source types end up having the same LLVM type, that the dumper will sometimes
822 print the "wrong" or unexpected type. This is an important design point and
823 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]824
825</div>
826
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]827<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]828<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]829 <a name="globalvars">Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]830</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]831
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]832<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]833
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]834<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]835 instead of run-time. Global variables may optionally be initialized, may
836 have an explicit section to be placed in, and may have an optional explicit
837 alignment specified. A variable may be defined as "thread_local", which
838 means that it will not be shared by threads (each thread will have a
839 separated copy of the variable). A variable may be defined as a global
840 "constant," which indicates that the contents of the variable
841 will <b>never</b> be modified (enabling better optimization, allowing the
842 global data to be placed in the read-only section of an executable, etc).
843 Note that variables that need runtime initialization cannot be marked
844 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]845
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]846<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
847 constant, even if the final definition of the global is not. This capability
848 can be used to enable slightly better optimization of the program, but
849 requires the language definition to guarantee that optimizations based on the
850 'constantness' are valid for the translation units that do not include the
851 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]852
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]853<p>As SSA values, global variables define pointer values that are in scope
854 (i.e. they dominate) all basic blocks in the program. Global variables
855 always define a pointer to their "content" type because they describe a
856 region of memory, and all memory objects in LLVM are accessed through
857 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]858
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]859<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
860 that the address is not significant, only the content. Constants marked
Rafael Espindolaa5eaa862011-01-15 08:20:57 +0000[diff] [blame]861 like this can be merged with other constants if they have the same
862 initializer. Note that a constant with significant address <em>can</em>
863 be merged with a <tt>unnamed_addr</tt> constant, the result being a
864 constant whose address is significant.</p>
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]865
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]866<p>A global variable may be declared to reside in a target-specific numbered
867 address space. For targets that support them, address spaces may affect how
868 optimizations are performed and/or what target instructions are used to
869 access the variable. The default address space is zero. The address space
870 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]871
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]872<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]873 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]874
Chris Lattnerce99fa92010-04-28 00:13:42 +0000[diff] [blame]875<p>An explicit alignment may be specified for a global, which must be a power
876 of 2. If not present, or if the alignment is set to zero, the alignment of
877 the global is set by the target to whatever it feels convenient. If an
878 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner2d4b8ee2010-04-28 00:31:12 +0000[diff] [blame]879 alignment. Targets and optimizers are not allowed to over-align the global
880 if the global has an assigned section. In this case, the extra alignment
881 could be observable: for example, code could assume that the globals are
882 densely packed in their section and try to iterate over them as an array,
883 alignment padding would break this iteration.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]884
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]885<p>For example, the following defines a global in a numbered address space with
886 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]887
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]888<pre class="doc_code">
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]889@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]890</pre>
891
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]892</div>
893
894
895<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]896<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]897 <a name="functionstructure">Functions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]898</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]899
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]900<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]901
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]902<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]903 optional <a href="#linkage">linkage type</a>, an optional
904 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]905 <a href="#callingconv">calling convention</a>,
906 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]907 <a href="#paramattrs">parameter attribute</a> for the return type, a function
908 name, a (possibly empty) argument list (each with optional
909 <a href="#paramattrs">parameter attributes</a>), optional
910 <a href="#fnattrs">function attributes</a>, an optional section, an optional
911 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
912 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]913
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]914<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
915 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]916 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]917 <a href="#callingconv">calling convention</a>,
918 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]919 <a href="#paramattrs">parameter attribute</a> for the return type, a function
920 name, a possibly empty list of arguments, an optional alignment, and an
921 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]922
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]923<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]924 (Control Flow Graph) for the function. Each basic block may optionally start
925 with a label (giving the basic block a symbol table entry), contains a list
926 of instructions, and ends with a <a href="#terminators">terminator</a>
927 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]928
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]929<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]930 executed on entrance to the function, and it is not allowed to have
931 predecessor basic blocks (i.e. there can not be any branches to the entry
932 block of a function). Because the block can have no predecessors, it also
933 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]934
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]935<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]936 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]937
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]938<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]939 the alignment is set to zero, the alignment of the function is set by the
940 target to whatever it feels convenient. If an explicit alignment is
941 specified, the function is forced to have at least that much alignment. All
942 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]943
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]944<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
945 be significant and two identical functions can be merged</p>.
946
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]947<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]948<pre class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]949define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]950 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
951 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
952 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
953 [<a href="#gc">gc</a>] { ... }
954</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]955
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]956</div>
957
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]958<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]959<h3>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]960 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]961</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]962
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]963<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]964
965<p>Aliases act as "second name" for the aliasee value (which can be either
966 function, global variable, another alias or bitcast of global value). Aliases
967 may have an optional <a href="#linkage">linkage type</a>, and an
968 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]969
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]970<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]971<pre class="doc_code">
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]972@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]973</pre>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]974
975</div>
976
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]977<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]978<h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]979 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]980</h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]981
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]982<div>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]983
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]984<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]985 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]986 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]987
988<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]989<pre class="doc_code">
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]990; Some unnamed metadata nodes, which are referenced by the named metadata.
991!0 = metadata !{metadata !"zero"}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]992!1 = metadata !{metadata !"one"}
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]993!2 = metadata !{metadata !"two"}
Dan Gohman1005bc52010-07-13 19:48:13 +0000[diff] [blame]994; A named metadata.
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]995!name = !{!0, !1, !2}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]996</pre>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]997
998</div>
999
1000<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1001<h3>
1002 <a name="paramattrs">Parameter Attributes</a>
1003</h3>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1004
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1005<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1006
1007<p>The return type and each parameter of a function type may have a set of
1008 <i>parameter attributes</i> associated with them. Parameter attributes are
1009 used to communicate additional information about the result or parameters of
1010 a function. Parameter attributes are considered to be part of the function,
1011 not of the function type, so functions with different parameter attributes
1012 can have the same function type.</p>
1013
1014<p>Parameter attributes are simple keywords that follow the type specified. If
1015 multiple parameter attributes are needed, they are space separated. For
1016 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1017
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1018<pre class="doc_code">
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]1019declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]1020declare i32 @atoi(i8 zeroext)
1021declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1022</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1023
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1024<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1025 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1026
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1027<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1028
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1029<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1030 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1031 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichebe81732011-03-16 22:20:18 +0000[diff] [blame]1032 should be zero-extended to the extent required by the target's ABI (which
1033 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1034 parameter) or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1035
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1036 <dt><tt><b>signext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1037 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich9e69ff92011-03-17 14:21:58 +0000[diff] [blame]1038 should be sign-extended to the extent required by the target's ABI (which
1039 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1040 return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1041
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1042 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1043 <dd>This indicates that this parameter or return value should be treated in a
1044 special target-dependent fashion during while emitting code for a function
1045 call or return (usually, by putting it in a register as opposed to memory,
1046 though some targets use it to distinguish between two different kinds of
1047 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1048
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1049 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1050 <dd><p>This indicates that the pointer parameter should really be passed by
1051 value to the function. The attribute implies that a hidden copy of the
1052 pointee
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1053 is made between the caller and the callee, so the callee is unable to
1054 modify the value in the callee. This attribute is only valid on LLVM
1055 pointer arguments. It is generally used to pass structs and arrays by
1056 value, but is also valid on pointers to scalars. The copy is considered
1057 to belong to the caller not the callee (for example,
1058 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1059 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1060 values.</p>
1061
1062 <p>The byval attribute also supports specifying an alignment with
1063 the align attribute. It indicates the alignment of the stack slot to
1064 form and the known alignment of the pointer specified to the call site. If
1065 the alignment is not specified, then the code generator makes a
1066 target-specific assumption.</p></dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1067
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1068 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1069 <dd>This indicates that the pointer parameter specifies the address of a
1070 structure that is the return value of the function in the source program.
1071 This pointer must be guaranteed by the caller to be valid: loads and
1072 stores to the structure may be assumed by the callee to not to trap. This
1073 may only be applied to the first parameter. This is not a valid attribute
1074 for return values. </dd>
1075
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1076 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1077 <dd>This indicates that pointer values
1078 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmanefca7f92010-07-02 23:46:54 +0000[diff] [blame]1079 value do not alias pointer values which are not <i>based</i> on it,
1080 ignoring certain "irrelevant" dependencies.
1081 For a call to the parent function, dependencies between memory
1082 references from before or after the call and from those during the call
1083 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1084 return value used in that call.
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1085 The caller shares the responsibility with the callee for ensuring that
1086 these requirements are met.
1087 For further details, please see the discussion of the NoAlias response in
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1088 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1089<br>
John McCall191d4ee2010-07-06 21:07:14 +0000[diff] [blame]1090 Note that this definition of <tt>noalias</tt> is intentionally
1091 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner211244a2010-07-06 20:51:35 +0000[diff] [blame]1092 arguments, though it is slightly weaker.
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1093<br>
1094 For function return values, C99's <tt>restrict</tt> is not meaningful,
1095 while LLVM's <tt>noalias</tt> is.
1096 </dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1097
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1098 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1099 <dd>This indicates that the callee does not make any copies of the pointer
1100 that outlive the callee itself. This is not a valid attribute for return
1101 values.</dd>
1102
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1103 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1104 <dd>This indicates that the pointer parameter can be excised using the
1105 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1106 attribute for return values.</dd>
1107</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1108
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1109</div>
1110
1111<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1112<h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1113 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1114</h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1115
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1116<div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1117
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1118<p>Each function may specify a garbage collector name, which is simply a
1119 string:</p>
1120
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1121<pre class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1122define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1123</pre>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1124
1125<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1126 collector which will cause the compiler to alter its output in order to
1127 support the named garbage collection algorithm.</p>
1128
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1129</div>
1130
1131<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1132<h3>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1133 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1134</h3>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1135
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1136<div>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1137
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1138<p>Function attributes are set to communicate additional information about a
1139 function. Function attributes are considered to be part of the function, not
1140 of the function type, so functions with different parameter attributes can
1141 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1142
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1143<p>Function attributes are simple keywords that follow the type specified. If
1144 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1145
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1146<pre class="doc_code">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1147define void @f() noinline { ... }
1148define void @f() alwaysinline { ... }
1149define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1150define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1151</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1152
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1153<dl>
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1154 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1155 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1156 the backend should forcibly align the stack pointer. Specify the
1157 desired alignment, which must be a power of two, in parentheses.
1158
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1159 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1160 <dd>This attribute indicates that the inliner should attempt to inline this
1161 function into callers whenever possible, ignoring any active inlining size
1162 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1163
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1164 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis6f12e292010-10-25 16:29:03 +0000[diff] [blame]1165 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis0076d202010-10-25 19:07:39 +0000[diff] [blame]1166 meaning the function can be patched and/or hooked even while it is
1167 loaded into memory. On x86, the function prologue will be preceded
1168 by six bytes of padding and will begin with a two-byte instruction.
1169 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1170 higher were compiled in this fashion.</dd>
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1171
Dan Gohman129bd562011-06-16 16:03:13 +0000[diff] [blame]1172 <dt><tt><b>nonlazybind</b></tt></dt>
1173 <dd>This attribute suppresses lazy symbol binding for the function. This
1174 may make calls to the function faster, at the cost of extra program
1175 startup time if the function is not called during program startup.</dd>
1176
Jakob Stoklund Olesen570a4a52010-02-06 01:16:28 +0000[diff] [blame]1177 <dt><tt><b>inlinehint</b></tt></dt>
1178 <dd>This attribute indicates that the source code contained a hint that inlining
1179 this function is desirable (such as the "inline" keyword in C/C++). It
1180 is just a hint; it imposes no requirements on the inliner.</dd>
1181
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1182 <dt><tt><b>naked</b></tt></dt>
1183 <dd>This attribute disables prologue / epilogue emission for the function.
1184 This can have very system-specific consequences.</dd>
1185
1186 <dt><tt><b>noimplicitfloat</b></tt></dt>
1187 <dd>This attributes disables implicit floating point instructions.</dd>
1188
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1189 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1190 <dd>This attribute indicates that the inliner should never inline this
1191 function in any situation. This attribute may not be used together with
1192 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1193
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1194 <dt><tt><b>noredzone</b></tt></dt>
1195 <dd>This attribute indicates that the code generator should not use a red
1196 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1197
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1198 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1199 <dd>This function attribute indicates that the function never returns
1200 normally. This produces undefined behavior at runtime if the function
1201 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1202
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1203 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1204 <dd>This function attribute indicates that the function never returns with an
1205 unwind or exceptional control flow. If the function does unwind, its
1206 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1207
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1208 <dt><tt><b>optsize</b></tt></dt>
1209 <dd>This attribute suggests that optimization passes and code generator passes
1210 make choices that keep the code size of this function low, and otherwise
1211 do optimizations specifically to reduce code size.</dd>
1212
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1213 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1214 <dd>This attribute indicates that the function computes its result (or decides
1215 to unwind an exception) based strictly on its arguments, without
1216 dereferencing any pointer arguments or otherwise accessing any mutable
1217 state (e.g. memory, control registers, etc) visible to caller functions.
1218 It does not write through any pointer arguments
1219 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1220 changes any state visible to callers. This means that it cannot unwind
1221 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1222 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1223
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1224 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1225 <dd>This attribute indicates that the function does not write through any
1226 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1227 arguments) or otherwise modify any state (e.g. memory, control registers,
1228 etc) visible to caller functions. It may dereference pointer arguments
1229 and read state that may be set in the caller. A readonly function always
1230 returns the same value (or unwinds an exception identically) when called
1231 with the same set of arguments and global state. It cannot unwind an
1232 exception by calling the <tt>C++</tt> exception throwing methods, but may
1233 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1234
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1235 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1236 <dd>This attribute indicates that the function should emit a stack smashing
1237 protector. It is in the form of a "canary"&mdash;a random value placed on
1238 the stack before the local variables that's checked upon return from the
1239 function to see if it has been overwritten. A heuristic is used to
1240 determine if a function needs stack protectors or not.<br>
1241<br>
1242 If a function that has an <tt>ssp</tt> attribute is inlined into a
1243 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1244 function will have an <tt>ssp</tt> attribute.</dd>
1245
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1246 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1247 <dd>This attribute indicates that the function should <em>always</em> emit a
1248 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1249 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1250<br>
1251 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1252 function that doesn't have an <tt>sspreq</tt> attribute or which has
1253 an <tt>ssp</tt> attribute, then the resulting function will have
1254 an <tt>sspreq</tt> attribute.</dd>
Rafael Espindolafbff0ec2011-07-25 15:27:59 +0000[diff] [blame]1255
1256 <dt><tt><b><a name="uwtable">uwtable</a></b></tt></dt>
1257 <dd>This attribute indicates that the ABI being targeted requires that
1258 an unwind table entry be produce for this function even if we can
1259 show that no exceptions passes by it. This is normally the case for
1260 the ELF x86-64 abi, but it can be disabled for some compilation
1261 units.</dd>
1262
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1263</dl>
1264
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1265</div>
1266
1267<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1268<h3>
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1269 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1270</h3>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1271
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1272<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1273
1274<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1275 the GCC "file scope inline asm" blocks. These blocks are internally
1276 concatenated by LLVM and treated as a single unit, but may be separated in
1277 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1278
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1279<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1280module asm "inline asm code goes here"
1281module asm "more can go here"
1282</pre>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1283
1284<p>The strings can contain any character by escaping non-printable characters.
1285 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]1286 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1287
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1288<p>The inline asm code is simply printed to the machine code .s file when
1289 assembly code is generated.</p>
1290
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1291</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1292
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1293<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1294<h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1295 <a name="datalayout">Data Layout</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1296</h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1297
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1298<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1299
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1300<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1301 data is to be laid out in memory. The syntax for the data layout is
1302 simply:</p>
1303
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1304<pre class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1305target datalayout = "<i>layout specification</i>"
1306</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1307
1308<p>The <i>layout specification</i> consists of a list of specifications
1309 separated by the minus sign character ('-'). Each specification starts with
1310 a letter and may include other information after the letter to define some
1311 aspect of the data layout. The specifications accepted are as follows:</p>
1312
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1313<dl>
1314 <dt><tt>E</tt></dt>
1315 <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]1316 bits with the most significance have the lowest address location.</dd>
1317
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1318 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1319 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1320 the bits with the least significance have the lowest address
1321 location.</dd>
1322
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1323 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1324 <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]1325 <i>preferred</i> alignments. All sizes are in bits. Specifying
1326 the <i>pref</i> alignment is optional. If omitted, the
1327 preceding <tt>:</tt> should be omitted too.</dd>
1328
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1329 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1330 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1331 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1332
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1333 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1334 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1335 <i>size</i>.</dd>
1336
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1337 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1338 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesen9d8d2212010-05-28 18:54:47 +0000[diff] [blame]1339 <i>size</i>. Only values of <i>size</i> that are supported by the target
1340 will work. 32 (float) and 64 (double) are supported on all targets;
1341 80 or 128 (different flavors of long double) are also supported on some
1342 targets.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1343
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1344 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1345 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1346 <i>size</i>.</dd>
1347
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1348 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1349 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1350 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1351
1352 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1353 <dd>This specifies a set of native integer widths for the target CPU
1354 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1355 "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]1356 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1357 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1358</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1359
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1360<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]1361 default set of specifications which are then (possibly) overridden by the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1362 specifications in the <tt>datalayout</tt> keyword. The default specifications
1363 are given in this list:</p>
1364
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1365<ul>
1366 <li><tt>E</tt> - big endian</li>
Dan Gohmanfdf2e8c2010-02-23 02:44:03 +0000[diff] [blame]1367 <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]1368 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1369 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1370 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1371 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1372 <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]1373 alignment of 64-bits</li>
1374 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1375 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1376 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1377 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1378 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1379 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1380</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1381
1382<p>When LLVM is determining the alignment for a given type, it uses the
1383 following rules:</p>
1384
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1385<ol>
1386 <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]1387 specification is used.</li>
1388
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1389 <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]1390 smallest integer type that is larger than the bitwidth of the sought type
1391 is used. If none of the specifications are larger than the bitwidth then
1392 the the largest integer type is used. For example, given the default
1393 specifications above, the i7 type will use the alignment of i8 (next
1394 largest) while both i65 and i256 will use the alignment of i64 (largest
1395 specified).</li>
1396
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1397 <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]1398 largest vector type that is smaller than the sought vector type will be
1399 used as a fall back. This happens because &lt;128 x double&gt; can be
1400 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1401</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1402
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1403</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1404
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1405<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1406<h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1407 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1408</h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1409
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1410<div>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1411
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1412<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1413with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1414is undefined. Pointer values are associated with address ranges
1415according to the following rules:</p>
1416
1417<ul>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1418 <li>A pointer value is associated with the addresses associated with
1419 any value it is <i>based</i> on.
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1420 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1421 range of the variable's storage.</li>
1422 <li>The result value of an allocation instruction is associated with
1423 the address range of the allocated storage.</li>
1424 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1425 no address.</li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1426 <li>An integer constant other than zero or a pointer value returned
1427 from a function not defined within LLVM may be associated with address
1428 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1429 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1430 allocated by mechanisms provided by LLVM.</li>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1431</ul>
1432
1433<p>A pointer value is <i>based</i> on another pointer value according
1434 to the following rules:</p>
1435
1436<ul>
1437 <li>A pointer value formed from a
1438 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1439 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1440 <li>The result value of a
1441 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1442 of the <tt>bitcast</tt>.</li>
1443 <li>A pointer value formed by an
1444 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1445 pointer values that contribute (directly or indirectly) to the
1446 computation of the pointer's value.</li>
1447 <li>The "<i>based</i> on" relationship is transitive.</li>
1448</ul>
1449
1450<p>Note that this definition of <i>"based"</i> is intentionally
1451 similar to the definition of <i>"based"</i> in C99, though it is
1452 slightly weaker.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1453
1454<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1455<tt><a href="#i_load">load</a></tt> merely indicates the size and
1456alignment of the memory from which to load, as well as the
Dan Gohmanc22c0f32010-06-17 19:23:50 +0000[diff] [blame]1457interpretation of the value. The first operand type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1458<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1459and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1460
1461<p>Consequently, type-based alias analysis, aka TBAA, aka
1462<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1463LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1464additional information which specialized optimization passes may use
1465to implement type-based alias analysis.</p>
1466
1467</div>
1468
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1469<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1470<h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1471 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1472</h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1473
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1474<div>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1475
1476<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1477href="#i_store"><tt>store</tt></a>s, and <a
1478href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1479The optimizers must not change the number of volatile operations or change their
1480order of execution relative to other volatile operations. The optimizers
1481<i>may</i> change the order of volatile operations relative to non-volatile
1482operations. This is not Java's "volatile" and has no cross-thread
1483synchronization behavior.</p>
1484
1485</div>
1486
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1487<!-- ======================================================================= -->
1488<h3>
1489 <a name="memmodel">Memory Model for Concurrent Operations</a>
1490</h3>
1491
1492<div>
1493
1494<p>The LLVM IR does not define any way to start parallel threads of execution
1495or to register signal handlers. Nonetheless, there are platform-specific
1496ways to create them, and we define LLVM IR's behavior in their presence. This
1497model is inspired by the C++0x memory model.</p>
1498
1499<p>We define a <i>happens-before</i> partial order as the least partial order
1500that</p>
1501<ul>
1502 <li>Is a superset of single-thread program order, and</li>
1503 <li>When a <i>synchronizes-with</i> <tt>b</tt>, includes an edge from
1504 <tt>a</tt> to <tt>b</tt>. <i>Synchronizes-with</i> pairs are introduced
1505 by platform-specific techniques, like pthread locks, thread
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame^]1506 creation, thread joining, etc., and by atomic instructions.
1507 (See also <a href="#ordering">Atomic Memory Ordering Constraints</a>).
1508 </li>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1509</ul>
1510
1511<p>Note that program order does not introduce <i>happens-before</i> edges
1512between a thread and signals executing inside that thread.</p>
1513
1514<p>Every (defined) read operation (load instructions, memcpy, atomic
1515loads/read-modify-writes, etc.) <var>R</var> reads a series of bytes written by
1516(defined) write operations (store instructions, atomic
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1517stores/read-modify-writes, memcpy, etc.). For the purposes of this section,
1518initialized globals are considered to have a write of the initializer which is
1519atomic and happens before any other read or write of the memory in question.
1520For each byte of a read <var>R</var>, <var>R<sub>byte</sub></var> may see
1521any write to the same byte, except:</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1522
1523<ul>
1524 <li>If <var>write<sub>1</sub></var> happens before
1525 <var>write<sub>2</sub></var>, and <var>write<sub>2</sub></var> happens
1526 before <var>R<sub>byte</sub></var>, then <var>R<sub>byte</sub></var>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1527 does not see <var>write<sub>1</sub></var>.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1528 <li>If <var>R<sub>byte</sub></var> happens before <var>write<sub>3</var>,
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1529 then <var>R<sub>byte</sub></var> does not see
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1530 <var>write<sub>3</sub></var>.
1531</ul>
1532
1533<p>Given that definition, <var>R<sub>byte</sub></var> is defined as follows:
1534<ul>
1535 <li>If there is no write to the same byte that happens before
1536 <var>R<sub>byte</sub></var>, <var>R<sub>byte</sub></var> returns
1537 <tt>undef</tt> for that byte.
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1538 <li>Otherwise, if <var>R<sub>byte</sub></var> may see exactly one write,
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1539 <var>R<sub>byte</sub></var> returns the value written by that
1540 write.</li>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1541 <li>Otherwise, if <var>R</var> is atomic, and all the writes
1542 <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^]1543 values written. See the <a href="#ordering">Atomic Memory Ordering
1544 Constraints</a> section for additional constraints on how the choice
1545 is made.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1546 <li>Otherwise <var>R<sub>byte</sub></var> returns <tt>undef</tt>.</li>
1547</ul>
1548
1549<p><var>R</var> returns the value composed of the series of bytes it read.
1550This implies that some bytes within the value may be <tt>undef</tt>
1551<b>without</b> the entire value being <tt>undef</tt>. Note that this only
1552defines the semantics of the operation; it doesn't mean that targets will
1553emit more than one instruction to read the series of bytes.</p>
1554
1555<p>Note that in cases where none of the atomic intrinsics are used, this model
1556places only one restriction on IR transformations on top of what is required
1557for single-threaded execution: introducing a store to a byte which might not
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1558otherwise be stored to can introduce undefined behavior. (Specifically, in
1559the case where another thread might write to and read from an address,
1560introducing a store can change a load that may see exactly one write into
1561a load that may see multiple writes.)</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1562
1563<!-- FIXME: This model assumes all targets where concurrency is relevant have
1564a byte-size store which doesn't affect adjacent bytes. As far as I can tell,
1565none of the backends currently in the tree fall into this category; however,
1566there might be targets which care. If there are, we want a paragraph
1567like the following:
1568
1569Targets may specify that stores narrower than a certain width are not
1570available; on such a target, for the purposes of this model, treat any
1571non-atomic write with an alignment or width less than the minimum width
1572as if it writes to the relevant surrounding bytes.
1573-->
1574
1575</div>
1576
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame^]1577<!-- ======================================================================= -->
1578<div class="doc_subsection">
1579 <a name="ordering">Atomic Memory Ordering Constraints</a>
1580</div>
1581
1582<div class="doc_text">
1583
1584<p>Atomic instructions (<a href="#i_cmpxchg"><code>cmpxchg</code></a>,
1585<a href="#i_atomicrmw"><code>atomicrmw</code></a>, and
1586<a href="#i_fence"><code>fence</code></a>) take an ordering parameter
1587that determines which other atomic instructions on the same address they
1588<i>synchronize with</i>. These semantics are borrowed from Java and C++0x,
1589but are somewhat more colloquial. If these descriptions aren't precise enough,
1590check those specs. <a href="#i_fence"><code>fence</code></a> instructions
1591treat these orderings somewhat differently since they don't take an address.
1592See that instruction's documentation for details.</p>
1593
1594<!-- FIXME Note atomic load+store here once those get added. -->
1595
1596<dl>
1597<!-- FIXME: unordered is intended to be used for atomic load and store;
1598it isn't allowed for any instruction yet. -->
1599<dt><code>unordered</code></dt>
1600<dd>The set of values that can be read is governed by the happens-before
1601partial order. A value cannot be read unless some operation wrote it.
1602This is intended to provide a guarantee strong enough to model Java's
1603non-volatile shared variables. This ordering cannot be specified for
1604read-modify-write operations; it is not strong enough to make them atomic
1605in any interesting way.</dd>
1606<dt><code>monotonic</code></dt>
1607<dd>In addition to the guarantees of <code>unordered</code>, there is a single
1608total order for modifications by <code>monotonic</code> operations on each
1609address. All modification orders must be compatible with the happens-before
1610order. There is no guarantee that the modification orders can be combined to
1611a global total order for the whole program (and this often will not be
1612possible). The read in an atomic read-modify-write operation
1613(<a href="#i_cmpxchg"><code>cmpxchg</code></a> and
1614<a href="#i_atomicrmw"><code>atomicrmw</code></a>)
1615reads the value in the modification order immediately before the value it
1616writes. If one atomic read happens before another atomic read of the same
1617address, the later read must see the same value or a later value in the
1618address's modification order. This disallows reordering of
1619<code>monotonic</code> (or stronger) operations on the same address. If an
1620address is written <code>monotonic</code>ally by one thread, and other threads
1621<code>monotonic</code>ally read that address repeatedly, the other threads must
1622eventually see the write. This is intended to model C++'s relaxed atomic
1623variables.</dd>
1624<dt><code>acquire</code></dt>
1625<dd>In addition to the guarantees of <code>monotonic</code>, if this operation
1626reads a value written by a <code>release</code> atomic operation, it
1627<i>synchronizes-with</i> that operation.</dd>
1628<dt><code>release</code></dt>
1629<dd>In addition to the guarantees of <code>monotonic</code>,
1630a <i>synchronizes-with</i> edge may be formed by an <code>acquire</code>
1631operation.</dd>
1632<dt><code>acq_rel</code> (acquire+release)</dt><dd>Acts as both an
1633<code>acquire</code> and <code>release</code> operation on its address.</dd>
1634<dt><code>seq_cst</code> (sequentially consistent)</dt><dd>
1635<dd>In addition to the guarantees of <code>acq_rel</code>
1636(<code>acquire</code> for an operation which only reads, <code>release</code>
1637for an operation which only writes), there is a global total order on all
1638sequentially-consistent operations on all addresses, which is consistent with
1639the <i>happens-before</i> partial order and with the modification orders of
1640all the affected addresses. Each sequentially-consistent read sees the last
1641preceding write to the same address in this global order. This is intended
1642to model C++'s sequentially-consistent atomic variables and Java's volatile
1643shared variables.</dd>
1644</dl>
1645
1646<p id="singlethread">If an atomic operation is marked <code>singlethread</code>,
1647it only <i>synchronizes with</i> or participates in modification and seq_cst
1648total orderings with other operations running in the same thread (for example,
1649in signal handlers).</p>
1650
1651</div>
1652
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1653</div>
1654
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1655<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1656<h2><a name="typesystem">Type System</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1657<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1658
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1659<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1660
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1661<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1662 intermediate representation. Being typed enables a number of optimizations
1663 to be performed on the intermediate representation directly, without having
1664 to do extra analyses on the side before the transformation. A strong type
1665 system makes it easier to read the generated code and enables novel analyses
1666 and transformations that are not feasible to perform on normal three address
1667 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1668
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1669<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1670<h3>
1671 <a name="t_classifications">Type Classifications</a>
1672</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1673
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1674<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1675
1676<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1677
1678<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1679 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1680 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1681 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1682 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1683 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1684 </tr>
1685 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1686 <td><a href="#t_floating">floating point</a></td>
1687 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1688 </tr>
1689 <tr>
1690 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1691 <td><a href="#t_integer">integer</a>,
1692 <a href="#t_floating">floating point</a>,
1693 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1694 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1695 <a href="#t_struct">structure</a>,
1696 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1697 <a href="#t_label">label</a>,
1698 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1699 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1700 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1701 <tr>
1702 <td><a href="#t_primitive">primitive</a></td>
1703 <td><a href="#t_label">label</a>,
1704 <a href="#t_void">void</a>,
Tobias Grosser05387292010-12-28 20:29:31 +0000[diff] [blame]1705 <a href="#t_integer">integer</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1706 <a href="#t_floating">floating point</a>,
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1707 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1708 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1709 </tr>
1710 <tr>
1711 <td><a href="#t_derived">derived</a></td>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1712 <td><a href="#t_array">array</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1713 <a href="#t_function">function</a>,
1714 <a href="#t_pointer">pointer</a>,
1715 <a href="#t_struct">structure</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1716 <a href="#t_vector">vector</a>,
1717 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1718 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1719 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1720 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1721</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1722
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1723<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1724 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1725 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1726
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1727</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1728
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1729<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1730<h3>
1731 <a name="t_primitive">Primitive Types</a>
1732</h3>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1733
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1734<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1735
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1736<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1737 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1738
1739<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1740<h4>
1741 <a name="t_integer">Integer Type</a>
1742</h4>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1743
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1744<div>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1745
1746<h5>Overview:</h5>
1747<p>The integer type is a very simple type that simply specifies an arbitrary
1748 bit width for the integer type desired. Any bit width from 1 bit to
1749 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1750
1751<h5>Syntax:</h5>
1752<pre>
1753 iN
1754</pre>
1755
1756<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1757 value.</p>
1758
1759<h5>Examples:</h5>
1760<table class="layout">
1761 <tr class="layout">
1762 <td class="left"><tt>i1</tt></td>
1763 <td class="left">a single-bit integer.</td>
1764 </tr>
1765 <tr class="layout">
1766 <td class="left"><tt>i32</tt></td>
1767 <td class="left">a 32-bit integer.</td>
1768 </tr>
1769 <tr class="layout">
1770 <td class="left"><tt>i1942652</tt></td>
1771 <td class="left">a really big integer of over 1 million bits.</td>
1772 </tr>
1773</table>
1774
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1775</div>
1776
1777<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1778<h4>
1779 <a name="t_floating">Floating Point Types</a>
1780</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1781
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1782<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1783
1784<table>
1785 <tbody>
1786 <tr><th>Type</th><th>Description</th></tr>
1787 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1788 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1789 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1790 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1791 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1792 </tbody>
1793</table>
1794
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1795</div>
1796
1797<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1798<h4>
1799 <a name="t_x86mmx">X86mmx Type</a>
1800</h4>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1801
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1802<div>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1803
1804<h5>Overview:</h5>
1805<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>
1806
1807<h5>Syntax:</h5>
1808<pre>
Dale Johannesen473a8c82010-10-01 01:07:02 +0000[diff] [blame]1809 x86mmx
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1810</pre>
1811
1812</div>
1813
1814<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1815<h4>
1816 <a name="t_void">Void Type</a>
1817</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1818
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1819<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1820
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1821<h5>Overview:</h5>
1822<p>The void type does not represent any value and has no size.</p>
1823
1824<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1825<pre>
1826 void
1827</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1828
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1829</div>
1830
1831<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1832<h4>
1833 <a name="t_label">Label Type</a>
1834</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1835
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1836<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1837
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1838<h5>Overview:</h5>
1839<p>The label type represents code labels.</p>
1840
1841<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1842<pre>
1843 label
1844</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1845
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1846</div>
1847
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1848<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1849<h4>
1850 <a name="t_metadata">Metadata Type</a>
1851</h4>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1852
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1853<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1854
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1855<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1856<p>The metadata type represents embedded metadata. No derived types may be
1857 created from metadata except for <a href="#t_function">function</a>
1858 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1859
1860<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1861<pre>
1862 metadata
1863</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1864
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1865</div>
1866
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1867</div>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1868
1869<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1870<h3>
1871 <a name="t_derived">Derived Types</a>
1872</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1873
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1874<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1875
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1876<p>The real power in LLVM comes from the derived types in the system. This is
1877 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1878 useful types. Each of these types contain one or more element types which
1879 may be a primitive type, or another derived type. For example, it is
1880 possible to have a two dimensional array, using an array as the element type
1881 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1882
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1883</div>
1884
1885
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1886<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1887<h4>
1888 <a name="t_aggregate">Aggregate Types</a>
1889</h4>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1890
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1891<div>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1892
1893<p>Aggregate Types are a subset of derived types that can contain multiple
1894 member types. <a href="#t_array">Arrays</a>,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]1895 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1896 aggregate types.</p>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1897
1898</div>
1899
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1900<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1901<h4>
1902 <a name="t_array">Array Type</a>
1903</h4>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1904
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1905<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1906
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1907<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1908<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1909 sequentially in memory. The array type requires a size (number of elements)
1910 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1911
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1912<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1913<pre>
1914 [&lt;# elements&gt; x &lt;elementtype&gt;]
1915</pre>
1916
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1917<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1918 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1919
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1920<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1921<table class="layout">
1922 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1923 <td class="left"><tt>[40 x i32]</tt></td>
1924 <td class="left">Array of 40 32-bit integer values.</td>
1925 </tr>
1926 <tr class="layout">
1927 <td class="left"><tt>[41 x i32]</tt></td>
1928 <td class="left">Array of 41 32-bit integer values.</td>
1929 </tr>
1930 <tr class="layout">
1931 <td class="left"><tt>[4 x i8]</tt></td>
1932 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1933 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1934</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1935<p>Here are some examples of multidimensional arrays:</p>
1936<table class="layout">
1937 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1938 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1939 <td class="left">3x4 array of 32-bit integer values.</td>
1940 </tr>
1941 <tr class="layout">
1942 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1943 <td class="left">12x10 array of single precision floating point values.</td>
1944 </tr>
1945 <tr class="layout">
1946 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1947 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1948 </tr>
1949</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1950
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1951<p>There is no restriction on indexing beyond the end of the array implied by
1952 a static type (though there are restrictions on indexing beyond the bounds
1953 of an allocated object in some cases). This means that single-dimension
1954 'variable sized array' addressing can be implemented in LLVM with a zero
1955 length array type. An implementation of 'pascal style arrays' in LLVM could
1956 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1957
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1958</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1959
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1960<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1961<h4>
1962 <a name="t_function">Function Type</a>
1963</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1964
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1965<div>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1966
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1967<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1968<p>The function type can be thought of as a function signature. It consists of
1969 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]1970 function type is a first class type or a void type.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1971
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1972<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1973<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1974 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1975</pre>
1976
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1977<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]1978 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1979 which indicates that the function takes a variable number of arguments.
1980 Variable argument functions can access their arguments with
1981 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1982 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1983 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1984
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1985<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1986<table class="layout">
1987 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1988 <td class="left"><tt>i32 (i32)</tt></td>
1989 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1990 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1991 </tr><tr class="layout">
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1992 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1993 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1994 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1995 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1996 returning <tt>float</tt>.
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1997 </td>
1998 </tr><tr class="layout">
1999 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2000 <td class="left">A vararg function that takes at least one
2001 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
2002 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]2003 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2004 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]2005 </tr><tr class="layout">
2006 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]2007 <td class="left">A function taking an <tt>i32</tt>, returning a
2008 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]2009 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2010 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2011</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2012
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2013</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2014
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2015<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2016<h4>
2017 <a name="t_struct">Structure Type</a>
2018</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2019
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2020<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2021
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2022<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2023<p>The structure type is used to represent a collection of data members together
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2024 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]2025
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]2026<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
2027 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
2028 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
2029 Structures in registers are accessed using the
2030 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
2031 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2032
2033<p>Structures may optionally be "packed" structures, which indicate that the
2034 alignment of the struct is one byte, and that there is no padding between
2035 the elements. In non-packed structs, padding between field types is defined
2036 by the target data string to match the underlying processor.</p>
2037
2038<p>Structures can either be "anonymous" or "named". An anonymous structure is
2039 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) and a named types
2040 are always defined at the top level with a name. Anonmyous types are uniqued
2041 by their contents and can never be recursive since there is no way to write
2042 one. Named types can be recursive.
2043</p>
2044
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2045<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2046<pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2047 %T1 = type { &lt;type list&gt; } <i>; Named normal struct type</i>
2048 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Named packed struct type</i>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2049</pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2050
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2051<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2052<table class="layout">
2053 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2054 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
2055 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2056 </tr>
2057 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2058 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
2059 <td class="left">A pair, where the first element is a <tt>float</tt> and the
2060 second element is a <a href="#t_pointer">pointer</a> to a
2061 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
2062 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2063 </tr>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2064 <tr class="layout">
2065 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
2066 <td class="left">A packed struct known to be 5 bytes in size.</td>
2067 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2068</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2069
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2070</div>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2071
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2072<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2073<h4>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]2074 <a name="t_opaque">Opaque Structure Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2075</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2076
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2077<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2078
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2079<h5>Overview:</h5>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]2080<p>Opaque structure types are used to represent named structure types that do
2081 not have a body specified. This corresponds (for example) to the C notion of
2082 a forward declared structure.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2083
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2084<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2085<pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2086 %X = type opaque
2087 %52 = type opaque
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2088</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2089
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2090<h5>Examples:</h5>
2091<table class="layout">
2092 <tr class="layout">
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2093 <td class="left"><tt>opaque</tt></td>
2094 <td class="left">An opaque type.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2095 </tr>
2096</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2097
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2098</div>
2099
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2100
2101
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2102<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2103<h4>
2104 <a name="t_pointer">Pointer Type</a>
2105</h4>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2106
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2107<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2108
2109<h5>Overview:</h5>
Dan Gohmanff3ef322010-02-25 16:50:07 +0000[diff] [blame]2110<p>The pointer type is used to specify memory locations.
2111 Pointers are commonly used to reference objects in memory.</p>
2112
2113<p>Pointer types may have an optional address space attribute defining the
2114 numbered address space where the pointed-to object resides. The default
2115 address space is number zero. The semantics of non-zero address
2116 spaces are target-specific.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2117
2118<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
2119 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2120
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2121<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2122<pre>
2123 &lt;type&gt; *
2124</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2125
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2126<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2127<table class="layout">
2128 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2129 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2130 <td class="left">A <a href="#t_pointer">pointer</a> to <a
2131 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
2132 </tr>
2133 <tr class="layout">
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]2134 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2135 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2136 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2137 <tt>i32</tt>.</td>
2138 </tr>
2139 <tr class="layout">
2140 <td class="left"><tt>i32 addrspace(5)*</tt></td>
2141 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
2142 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2143 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2144</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2145
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2146</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2147
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2148<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2149<h4>
2150 <a name="t_vector">Vector Type</a>
2151</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2152
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2153<div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2154
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2155<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2156<p>A vector type is a simple derived type that represents a vector of elements.
2157 Vector types are used when multiple primitive data are operated in parallel
2158 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]2159 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2160 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2161
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2162<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2163<pre>
2164 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2165</pre>
2166
Chris Lattner7d2e7be2010-10-10 18:20:35 +0000[diff] [blame]2167<p>The number of elements is a constant integer value larger than 0; elementtype
2168 may be any integer or floating point type. Vectors of size zero are not
2169 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2170
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2171<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2172<table class="layout">
2173 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2174 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
2175 <td class="left">Vector of 4 32-bit integer values.</td>
2176 </tr>
2177 <tr class="layout">
2178 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
2179 <td class="left">Vector of 8 32-bit floating-point values.</td>
2180 </tr>
2181 <tr class="layout">
2182 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2183 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2184 </tr>
2185</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2186
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2187</div>
2188
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2189<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2190<h2><a name="constants">Constants</a></h2>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2191<!-- *********************************************************************** -->
2192
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2193<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2194
2195<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2196 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2197
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2198<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2199<h3>
2200 <a name="simpleconstants">Simple Constants</a>
2201</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2202
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2203<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2204
2205<dl>
2206 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2207 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]2208 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2209
2210 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2211 <dd>Standard integers (such as '4') are constants of
2212 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2213 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2214
2215 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2216 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2217 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2218 notation (see below). The assembler requires the exact decimal value of a
2219 floating-point constant. For example, the assembler accepts 1.25 but
2220 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2221 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2222
2223 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2224 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2225 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2226</dl>
2227
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2228<p>The one non-intuitive notation for constants is the hexadecimal form of
2229 floating point constants. For example, the form '<tt>double
2230 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2231 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2232 constants are required (and the only time that they are generated by the
2233 disassembler) is when a floating point constant must be emitted but it cannot
2234 be represented as a decimal floating point number in a reasonable number of
2235 digits. For example, NaN's, infinities, and other special values are
2236 represented in their IEEE hexadecimal format so that assembly and disassembly
2237 do not cause any bits to change in the constants.</p>
2238
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]2239<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2240 represented using the 16-digit form shown above (which matches the IEEE754
2241 representation for double); float values must, however, be exactly
2242 representable as IEE754 single precision. Hexadecimal format is always used
2243 for long double, and there are three forms of long double. The 80-bit format
2244 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2245 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2246 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2247 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2248 currently supported target uses this format. Long doubles will only work if
2249 they match the long double format on your target. All hexadecimal formats
2250 are big-endian (sign bit at the left).</p>
2251
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]2252<p>There are no constants of type x86mmx.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2253</div>
2254
2255<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2256<h3>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2257<a name="aggregateconstants"></a> <!-- old anchor -->
2258<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2259</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2260
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2261<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2262
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2263<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2264 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2265
2266<dl>
2267 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2268 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2269 type definitions (a comma separated list of elements, surrounded by braces
2270 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2271 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2272 Structure constants must have <a href="#t_struct">structure type</a>, and
2273 the number and types of elements must match those specified by the
2274 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2275
2276 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2277 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2278 definitions (a comma separated list of elements, surrounded by square
2279 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2280 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2281 the number and types of elements must match those specified by the
2282 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2283
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2284 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2285 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2286 definitions (a comma separated list of elements, surrounded by
2287 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2288 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2289 have <a href="#t_vector">vector type</a>, and the number and types of
2290 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2291
2292 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2293 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2294 value to zero of <em>any</em> type, including scalar and
2295 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2296 This is often used to avoid having to print large zero initializers
2297 (e.g. for large arrays) and is always exactly equivalent to using explicit
2298 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2299
2300 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2301 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2302 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2303 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2304 be interpreted as part of the instruction stream, metadata is a place to
2305 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2306</dl>
2307
2308</div>
2309
2310<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2311<h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2312 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2313</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2314
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2315<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2316
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2317<p>The addresses of <a href="#globalvars">global variables</a>
2318 and <a href="#functionstructure">functions</a> are always implicitly valid
2319 (link-time) constants. These constants are explicitly referenced when
2320 the <a href="#identifiers">identifier for the global</a> is used and always
2321 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2322 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2323
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2324<pre class="doc_code">
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2325@X = global i32 17
2326@Y = global i32 42
2327@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2328</pre>
2329
2330</div>
2331
2332<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2333<h3>
2334 <a name="undefvalues">Undefined Values</a>
2335</h3>
2336
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2337<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2338
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2339<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]2340 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2341 Undefined values may be of any type (other than '<tt>label</tt>'
2342 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2343
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2344<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2345 program is well defined no matter what value is used. This gives the
2346 compiler more freedom to optimize. Here are some examples of (potentially
2347 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2348
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2349
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2350<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2351 %A = add %X, undef
2352 %B = sub %X, undef
2353 %C = xor %X, undef
2354Safe:
2355 %A = undef
2356 %B = undef
2357 %C = undef
2358</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2359
2360<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]2361 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]2362
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2363<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2364 %A = or %X, undef
2365 %B = and %X, undef
2366Safe:
2367 %A = -1
2368 %B = 0
2369Unsafe:
2370 %A = undef
2371 %B = undef
2372</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2373
2374<p>These logical operations have bits that are not always affected by the input.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2375 For example, if <tt>%X</tt> has a zero bit, then the output of the
2376 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2377 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2378 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2379 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2380 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2381 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2382 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2383
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2384<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2385 %A = select undef, %X, %Y
2386 %B = select undef, 42, %Y
2387 %C = select %X, %Y, undef
2388Safe:
2389 %A = %X (or %Y)
2390 %B = 42 (or %Y)
2391 %C = %Y
2392Unsafe:
2393 %A = undef
2394 %B = undef
2395 %C = undef
2396</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2397
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2398<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2399 branch) conditions can go <em>either way</em>, but they have to come from one
2400 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2401 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2402 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2403 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2404 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2405 eliminated.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2406
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2407<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2408 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2409
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2410 %B = undef
2411 %C = xor %B, %B
2412
2413 %D = undef
2414 %E = icmp lt %D, 4
2415 %F = icmp gte %D, 4
2416
2417Safe:
2418 %A = undef
2419 %B = undef
2420 %C = undef
2421 %D = undef
2422 %E = undef
2423 %F = undef
2424</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2425
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2426<p>This example points out that two '<tt>undef</tt>' operands are not
2427 necessarily the same. This can be surprising to people (and also matches C
2428 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2429 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2430 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2431 its value over its "live range". This is true because the variable doesn't
2432 actually <em>have a live range</em>. Instead, the value is logically read
2433 from arbitrary registers that happen to be around when needed, so the value
2434 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2435 need to have the same semantics or the core LLVM "replace all uses with"
2436 concept would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2437
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2438<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2439 %A = fdiv undef, %X
2440 %B = fdiv %X, undef
2441Safe:
2442 %A = undef
2443b: unreachable
2444</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2445
2446<p>These examples show the crucial difference between an <em>undefined
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2447 value</em> and <em>undefined behavior</em>. An undefined value (like
2448 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2449 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2450 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2451 defined on SNaN's. However, in the second example, we can make a more
2452 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2453 arbitrary value, we are allowed to assume that it could be zero. Since a
2454 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2455 the operation does not execute at all. This allows us to delete the divide and
2456 all code after it. Because the undefined operation "can't happen", the
2457 optimizer can assume that it occurs in dead code.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2458
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2459<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2460a: store undef -> %X
2461b: store %X -> undef
2462Safe:
2463a: &lt;deleted&gt;
2464b: unreachable
2465</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2466
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2467<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2468 undefined value can be assumed to not have any effect; we can assume that the
2469 value is overwritten with bits that happen to match what was already there.
2470 However, a store <em>to</em> an undefined location could clobber arbitrary
2471 memory, therefore, it has undefined behavior.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2472
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2473</div>
2474
2475<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2476<h3>
2477 <a name="trapvalues">Trap Values</a>
2478</h3>
2479
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2480<div>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2481
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2482<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2483 instead of representing an unspecified bit pattern, they represent the
2484 fact that an instruction or constant expression which cannot evoke side
2485 effects has nevertheless detected a condition which results in undefined
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2486 behavior.</p>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2487
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2488<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]2489 only exist when produced by operations such as
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2490 <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]2491
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2492<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2493
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2494<ul>
2495<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2496 their operands.</li>
2497
2498<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2499 to their dynamic predecessor basic block.</li>
2500
2501<li>Function arguments depend on the corresponding actual argument values in
2502 the dynamic callers of their functions.</li>
2503
2504<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2505 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2506 control back to them.</li>
2507
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2508<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2509 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2510 or exception-throwing call instructions that dynamically transfer control
2511 back to them.</li>
2512
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2513<li>Non-volatile loads and stores depend on the most recent stores to all of the
2514 referenced memory addresses, following the order in the IR
2515 (including loads and stores implied by intrinsics such as
2516 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2517
Dan Gohman7c24ff12010-05-03 14:59:34 +0000[diff] [blame]2518<!-- TODO: In the case of multiple threads, this only applies if the store
2519 "happens-before" the load or store. -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2520
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2521<!-- TODO: floating-point exception state -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2522
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2523<li>An instruction with externally visible side effects depends on the most
2524 recent preceding instruction with externally visible side effects, following
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]2525 the order in the IR. (This includes
2526 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2527
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2528<li>An instruction <i>control-depends</i> on a
2529 <a href="#terminators">terminator instruction</a>
2530 if the terminator instruction has multiple successors and the instruction
2531 is always executed when control transfers to one of the successors, and
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2532 may not be executed when control is transferred to another.</li>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2533
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2534<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2535 instruction if the set of instructions it otherwise depends on would be
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2536 different if the terminator had transferred control to a different
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2537 successor.</li>
2538
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2539<li>Dependence is transitive.</li>
2540
2541</ul>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2542
2543<p>Whenever a trap value is generated, all values which depend on it evaluate
2544 to trap. If they have side effects, the evoke their side effects as if each
2545 operand with a trap value were undef. If they have externally-visible side
2546 effects, the behavior is undefined.</p>
2547
2548<p>Here are some examples:</p>
Dan Gohmanc30f6e12010-04-26 20:54:53 +0000[diff] [blame]2549
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2550<pre class="doc_code">
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2551entry:
2552 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2553 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2554 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2555 store i32 0, i32* %trap_yet_again ; undefined behavior
2556
2557 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2558 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2559
2560 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2561
2562 %narrowaddr = bitcast i32* @g to i16*
2563 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2564 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2565 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2566
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2567 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2568 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2569
2570true:
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2571 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2572 ; it has undefined behavior.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2573 br label %end
2574
2575end:
2576 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2577 ; Both edges into this PHI are
2578 ; control-dependent on %cmp, so this
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2579 ; always results in a trap value.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2580
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2581 volatile store i32 0, i32* @g ; This would depend on the store in %true
2582 ; if %cmp is true, or the store in %entry
2583 ; otherwise, so this is undefined behavior.
2584
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2585 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2586 ; The same branch again, but this time the
2587 ; true block doesn't have side effects.
2588
2589second_true:
2590 ; No side effects!
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2591 ret void
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2592
2593second_end:
2594 volatile store i32 0, i32* @g ; This time, the instruction always depends
2595 ; on the store in %end. Also, it is
2596 ; control-equivalent to %end, so this is
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2597 ; well-defined (again, ignoring earlier
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2598 ; undefined behavior in this example).
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2599</pre>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2600
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2601</div>
2602
2603<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2604<h3>
2605 <a name="blockaddress">Addresses of Basic Blocks</a>
2606</h3>
2607
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2608<div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2609
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2610<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2611
2612<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2613 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2614 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2615
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2616<p>This value only has defined behavior when used as an operand to the
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2617 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2618 comparisons against null. Pointer equality tests between labels addresses
2619 results in undefined behavior &mdash; though, again, comparison against null
2620 is ok, and no label is equal to the null pointer. This may be passed around
2621 as an opaque pointer sized value as long as the bits are not inspected. This
2622 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2623 long as the original value is reconstituted before the <tt>indirectbr</tt>
2624 instruction.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2625
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2626<p>Finally, some targets may provide defined semantics when using the value as
2627 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2628
2629</div>
2630
2631
2632<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2633<h3>
2634 <a name="constantexprs">Constant Expressions</a>
2635</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2636
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2637<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2638
2639<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2640 to be used as constants. Constant expressions may be of
2641 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2642 operation that does not have side effects (e.g. load and call are not
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2643 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2644
2645<dl>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2646 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2647 <dd>Truncate a constant to another type. The bit size of CST must be larger
2648 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2649
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2650 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2651 <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]2652 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2653
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2654 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2655 <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]2656 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2657
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2658 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2659 <dd>Truncate a floating point constant to another floating point type. The
2660 size of CST must be larger than the size of TYPE. Both types must be
2661 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2662
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2663 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2664 <dd>Floating point extend a constant to another type. The size of CST must be
2665 smaller or equal to the size of TYPE. Both types must be floating
2666 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2667
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2668 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2669 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2670 constant. TYPE must be a scalar or vector integer type. CST must be of
2671 scalar or vector floating point type. Both CST and TYPE must be scalars,
2672 or vectors of the same number of elements. If the value won't fit in the
2673 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2674
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2675 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2676 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2677 constant. TYPE must be a scalar or vector integer type. CST must be of
2678 scalar or vector floating point type. Both CST and TYPE must be scalars,
2679 or vectors of the same number of elements. If the value won't fit in the
2680 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2681
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2682 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2683 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2684 constant. TYPE must be a scalar or vector floating point type. CST must be
2685 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2686 vectors of the same number of elements. If the value won't fit in the
2687 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2688
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2689 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2690 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2691 constant. TYPE must be a scalar or vector floating point type. CST must be
2692 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2693 vectors of the same number of elements. If the value won't fit in the
2694 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2695
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2696 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2697 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2698 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2699 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2700 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2701
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2702 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2703 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2704 type. CST must be of integer type. The CST value is zero extended,
2705 truncated, or unchanged to make it fit in a pointer size. This one is
2706 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2707
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2708 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2709 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2710 are the same as those for the <a href="#i_bitcast">bitcast
2711 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2712
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2713 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2714 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2715 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2716 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2717 instruction, the index list may have zero or more indexes, which are
2718 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2719
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2720 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2721 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2722
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2723 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2724 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2725
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2726 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2727 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2728
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2729 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2730 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2731 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2732
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2733 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2734 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2735 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2736
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2737 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2738 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2739 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2740
Nick Lewycky9e130ce2010-05-29 06:44:15 +0000[diff] [blame]2741 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2742 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2743 constants. The index list is interpreted in a similar manner as indices in
2744 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2745 index value must be specified.</dd>
2746
2747 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2748 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2749 constants. The index list is interpreted in a similar manner as indices in
2750 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2751 index value must be specified.</dd>
2752
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2753 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2754 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2755 be any of the <a href="#binaryops">binary</a>
2756 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2757 on operands are the same as those for the corresponding instruction
2758 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2759</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2760
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2761</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2762
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2763</div>
2764
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2765<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2766<h2><a name="othervalues">Other Values</a></h2>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2767<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2768<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2769<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2770<h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2771<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2772</h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2773
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2774<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2775
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2776<p>LLVM supports inline assembler expressions (as opposed
2777 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2778 a special value. This value represents the inline assembler as a string
2779 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2780 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2781 expression has side effects, and a flag indicating whether the function
2782 containing the asm needs to align its stack conservatively. An example
2783 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2784
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2785<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2786i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2787</pre>
2788
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2789<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2790 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2791 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2792
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2793<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2794%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]2795</pre>
2796
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2797<p>Inline asms with side effects not visible in the constraint list must be
2798 marked as having side effects. This is done through the use of the
2799 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2800
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2801<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2802call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2803</pre>
2804
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2805<p>In some cases inline asms will contain code that will not work unless the
2806 stack is aligned in some way, such as calls or SSE instructions on x86,
2807 yet will not contain code that does that alignment within the asm.
2808 The compiler should make conservative assumptions about what the asm might
2809 contain and should generate its usual stack alignment code in the prologue
2810 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2811
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2812<pre class="doc_code">
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2813call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2814</pre>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2815
2816<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2817 first.</p>
2818
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2819<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2820 documented here. Constraints on what can be done (e.g. duplication, moving,
2821 etc need to be documented). This is probably best done by reference to
2822 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2823
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2824<h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2825<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2826</h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2827
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2828<div>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2829
2830<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2831 attached to it that contains a list of constant integers. If present, the
2832 code generator will use the integer as the location cookie value when report
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2833 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]2834 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2835 source code that produced it. For example:</p>
2836
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2837<pre class="doc_code">
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2838call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2839...
2840!42 = !{ i32 1234567 }
2841</pre>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2842
2843<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]2844 IR. If the MDNode contains multiple constants, the code generator will use
2845 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]2846
2847</div>
2848
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2849</div>
2850
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2851<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2852<h3>
2853 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2854</h3>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2855
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2856<div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2857
2858<p>LLVM IR allows metadata to be attached to instructions in the program that
2859 can convey extra information about the code to the optimizers and code
2860 generator. One example application of metadata is source-level debug
2861 information. There are two metadata primitives: strings and nodes. All
2862 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2863 preceding exclamation point ('<tt>!</tt>').</p>
2864
2865<p>A metadata string is a string surrounded by double quotes. It can contain
2866 any character by escaping non-printable characters with "\xx" where "xx" is
2867 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2868
2869<p>Metadata nodes are represented with notation similar to structure constants
2870 (a comma separated list of elements, surrounded by braces and preceded by an
2871 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2872 10}</tt>". Metadata nodes can have any values as their operand.</p>
2873
2874<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2875 metadata nodes, which can be looked up in the module symbol table. For
2876 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2877
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2878<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2879 function is using two metadata arguments.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2880
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2881<div class="doc_code">
2882<pre>
2883call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2884</pre>
2885</div>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2886
2887<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2888 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2889
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2890<div class="doc_code">
2891<pre>
2892%indvar.next = add i64 %indvar, 1, !dbg !21
2893</pre>
2894</div>
2895
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2896</div>
2897
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2898</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2899
2900<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2901<h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2902 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2903</h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2904<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2905<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2906<p>LLVM has a number of "magic" global variables that contain data that affect
2907code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2908of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2909section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2910by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2911
2912<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2913<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2914<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2915</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2916
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2917<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2918
2919<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2920href="#linkage_appending">appending linkage</a>. This array contains a list of
2921pointers to global variables and functions which may optionally have a pointer
2922cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2923
2924<pre>
2925 @X = global i8 4
2926 @Y = global i32 123
2927
2928 @llvm.used = appending global [2 x i8*] [
2929 i8* @X,
2930 i8* bitcast (i32* @Y to i8*)
2931 ], section "llvm.metadata"
2932</pre>
2933
2934<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2935compiler, assembler, and linker are required to treat the symbol as if there is
2936a reference to the global that it cannot see. For example, if a variable has
2937internal linkage and no references other than that from the <tt>@llvm.used</tt>
2938list, it cannot be deleted. This is commonly used to represent references from
2939inline asms and other things the compiler cannot "see", and corresponds to
2940"attribute((used))" in GNU C.</p>
2941
2942<p>On some targets, the code generator must emit a directive to the assembler or
2943object file to prevent the assembler and linker from molesting the symbol.</p>
2944
2945</div>
2946
2947<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2948<h3>
2949 <a name="intg_compiler_used">
2950 The '<tt>llvm.compiler.used</tt>' Global Variable
2951 </a>
2952</h3>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2953
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2954<div>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2955
2956<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2957<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2958touching the symbol. On targets that support it, this allows an intelligent
2959linker to optimize references to the symbol without being impeded as it would be
2960by <tt>@llvm.used</tt>.</p>
2961
2962<p>This is a rare construct that should only be used in rare circumstances, and
2963should not be exposed to source languages.</p>
2964
2965</div>
2966
2967<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2968<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2969<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2970</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2971
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2972<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2973<pre>
2974%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2975@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2976</pre>
2977<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.
2978</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2979
2980</div>
2981
2982<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2983<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2984<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2985</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2986
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2987<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2988<pre>
2989%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2990@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2991</pre>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2992
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2993<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.
2994</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2995
2996</div>
2997
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2998</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2999
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]3000<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3001<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3002<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3003
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3004<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3005
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3006<p>The LLVM instruction set consists of several different classifications of
3007 instructions: <a href="#terminators">terminator
3008 instructions</a>, <a href="#binaryops">binary instructions</a>,
3009 <a href="#bitwiseops">bitwise binary instructions</a>,
3010 <a href="#memoryops">memory instructions</a>, and
3011 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3012
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3013<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3014<h3>
3015 <a name="terminators">Terminator Instructions</a>
3016</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3017
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3018<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3019
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3020<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
3021 in a program ends with a "Terminator" instruction, which indicates which
3022 block should be executed after the current block is finished. These
3023 terminator instructions typically yield a '<tt>void</tt>' value: they produce
3024 control flow, not values (the one exception being the
3025 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
3026
Bill Wendling772fe172011-07-27 20:18:04 +0000[diff] [blame]3027<p>There are eight different terminator instructions: the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3028 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
3029 '<a href="#i_br"><tt>br</tt></a>' instruction, the
3030 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling21c346e2009-11-02 00:25:26 +0000[diff] [blame]3031 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3032 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
Bill Wendling772fe172011-07-27 20:18:04 +0000[diff] [blame]3033 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, the
3034 '<a href="#i_resume"><tt>resume</tt></a>' instruction, and the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3035 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3036
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3037<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3038<h4>
3039 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
3040</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3041
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3042<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3043
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3044<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]3045<pre>
3046 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]3047 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3048</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3049
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3050<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3051<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
3052 a value) from a function back to the caller.</p>
3053
3054<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
3055 value and then causes control flow, and one that just causes control flow to
3056 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3057
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3058<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3059<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
3060 return value. The type of the return value must be a
3061 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]3062
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3063<p>A function is not <a href="#wellformed">well formed</a> if it it has a
3064 non-void return type and contains a '<tt>ret</tt>' instruction with no return
3065 value or a return value with a type that does not match its type, or if it
3066 has a void return type and contains a '<tt>ret</tt>' instruction with a
3067 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3068
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3069<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3070<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
3071 the calling function's context. If the caller is a
3072 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
3073 instruction after the call. If the caller was an
3074 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
3075 the beginning of the "normal" destination block. If the instruction returns
3076 a value, that value shall set the call or invoke instruction's return
3077 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3078
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3079<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3080<pre>
3081 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3082 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]3083 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]3084</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3085
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3086</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3087<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3088<h4>
3089 <a name="i_br">'<tt>br</tt>' Instruction</a>
3090</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3091
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3092<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3093
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3094<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3095<pre>
Bill Wendlingb3aa4712011-07-26 10:41:15 +0000[diff] [blame]3096 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;
3097 br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3098</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3099
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3100<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3101<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3102 different basic block in the current function. There are two forms of this
3103 instruction, corresponding to a conditional branch and an unconditional
3104 branch.</p>
3105
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3106<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3107<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3108 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3109 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3110 target.</p>
3111
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3112<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3113<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3114 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3115 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3116 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3117
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3118<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]3119<pre>
3120Test:
3121 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3122 br i1 %cond, label %IfEqual, label %IfUnequal
3123IfEqual:
3124 <a href="#i_ret">ret</a> i32 1
3125IfUnequal:
3126 <a href="#i_ret">ret</a> i32 0
3127</pre>
3128
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3129</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3130
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3131<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3132<h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3133 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3134</h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3135
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3136<div>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3137
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3138<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3139<pre>
3140 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3141</pre>
3142
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3143<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3144<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]3145 several different places. It is a generalization of the '<tt>br</tt>'
3146 instruction, allowing a branch to occur to one of many possible
3147 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3148
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3149<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3150<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3151 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3152 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3153 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3154
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3155<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3156<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3157 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3158 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]3159 transferred to the corresponding destination; otherwise, control flow is
3160 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3161
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3162<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3163<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3164 <tt>switch</tt> instruction, this instruction may be code generated in
3165 different ways. For example, it could be generated as a series of chained
3166 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3167
3168<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3169<pre>
3170 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3171 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3172 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3173
3174 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3175 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3176
3177 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3178 switch i32 %val, label %otherwise [ i32 0, label %onzero
3179 i32 1, label %onone
3180 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3181</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3182
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3183</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3184
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3185
3186<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3187<h4>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3188 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3189</h4>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3190
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3191<div>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3192
3193<h5>Syntax:</h5>
3194<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3195 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]3196</pre>
3197
3198<h5>Overview:</h5>
3199
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3200<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3201 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]3202 "<tt>address</tt>". Address must be derived from a <a
3203 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3204
3205<h5>Arguments:</h5>
3206
3207<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3208 rest of the arguments indicate the full set of possible destinations that the
3209 address may point to. Blocks are allowed to occur multiple times in the
3210 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3211
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3212<p>This destination list is required so that dataflow analysis has an accurate
3213 understanding of the CFG.</p>
3214
3215<h5>Semantics:</h5>
3216
3217<p>Control transfers to the block specified in the address argument. All
3218 possible destination blocks must be listed in the label list, otherwise this
3219 instruction has undefined behavior. This implies that jumps to labels
3220 defined in other functions have undefined behavior as well.</p>
3221
3222<h5>Implementation:</h5>
3223
3224<p>This is typically implemented with a jump through a register.</p>
3225
3226<h5>Example:</h5>
3227<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3228 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3229</pre>
3230
3231</div>
3232
3233
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3234<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3235<h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3236 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3237</h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3238
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3239<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3240
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3241<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3242<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3243 &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]3244 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3245</pre>
3246
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3247<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3248<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3249 function, with the possibility of control flow transfer to either the
3250 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3251 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3252 control flow will return to the "normal" label. If the callee (or any
3253 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3254 instruction, control is interrupted and continued at the dynamically nearest
3255 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3256
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3257<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3258<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3259
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3260<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3261 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3262 convention</a> the call should use. If none is specified, the call
3263 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3264
3265 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3266 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3267 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3268
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3269 <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]3270 function value being invoked. In most cases, this is a direct function
3271 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3272 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3273
3274 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3275 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3276
3277 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]3278 signature argument types and parameter attributes. All arguments must be
3279 of <a href="#t_firstclass">first class</a> type. If the function
3280 signature indicates the function accepts a variable number of arguments,
3281 the extra arguments can be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3282
3283 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3284 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3285
3286 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3287 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3288
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3289 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3290 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3291 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3292</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3293
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3294<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3295<p>This instruction is designed to operate as a standard
3296 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3297 primary difference is that it establishes an association with a label, which
3298 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3299
3300<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3301 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3302 exception. Additionally, this is important for implementation of
3303 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3304
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3305<p>For the purposes of the SSA form, the definition of the value returned by the
3306 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3307 block to the "normal" label. If the callee unwinds then no return value is
3308 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]3309
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3310<p>Note that the code generator does not yet completely support unwind, and
3311that the invoke/unwind semantics are likely to change in future versions.</p>
3312
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3313<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3314<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3315 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3316 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3317 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3318 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3319</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3320
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3321</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3322
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3323<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3324
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3325<h4>
3326 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3327</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3328
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3329<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3330
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3331<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3332<pre>
3333 unwind
3334</pre>
3335
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3336<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3337<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3338 at the first callee in the dynamic call stack which used
3339 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3340 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3341
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3342<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3343<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3344 immediately halt. The dynamic call stack is then searched for the
3345 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3346 Once found, execution continues at the "exceptional" destination block
3347 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3348 instruction in the dynamic call chain, undefined behavior results.</p>
3349
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3350<p>Note that the code generator does not yet completely support unwind, and
3351that the invoke/unwind semantics are likely to change in future versions.</p>
3352
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3353</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3354
3355<!-- _______________________________________________________________________ -->
3356
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3357<h4>
Bill Wendling772fe172011-07-27 20:18:04 +0000[diff] [blame]3358 <a name="i_resume">'<tt>resume</tt>' Instruction</a>
3359</h4>
3360
3361<div>
3362
3363<h5>Syntax:</h5>
3364<pre>
3365 resume &lt;type&gt; &lt;value&gt;
3366</pre>
3367
3368<h5>Overview:</h5>
3369<p>The '<tt>resume</tt>' instruction is a terminator instruction that has no
3370 successors. Its operand must have the same type as the result of any
3371 '<tt>landingpad</tt>' instruction in the same function.</p>
3372
3373<h5>Semantics:</h5>
3374<p>The '<tt>resume</tt>' instruction resumes propagation of an existing
3375 (in-flight) exception.</p>
3376
3377<h5>Example:</h5>
3378<pre>
3379 resume { i8*, i32 } %exn
3380</pre>
3381
3382</div>
3383
3384<!-- _______________________________________________________________________ -->
3385
3386<h4>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3387 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3388</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3389
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3390<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3391
3392<h5>Syntax:</h5>
3393<pre>
3394 unreachable
3395</pre>
3396
3397<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3398<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3399 instruction is used to inform the optimizer that a particular portion of the
3400 code is not reachable. This can be used to indicate that the code after a
3401 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3402
3403<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3404<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3405
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3406</div>
3407
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3408</div>
3409
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3410<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3411<h3>
3412 <a name="binaryops">Binary Operations</a>
3413</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3414
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3415<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3416
3417<p>Binary operators are used to do most of the computation in a program. They
3418 require two operands of the same type, execute an operation on them, and
3419 produce a single value. The operands might represent multiple data, as is
3420 the case with the <a href="#t_vector">vector</a> data type. The result value
3421 has the same type as its operands.</p>
3422
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3423<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3424
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3425<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3426<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3427 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3428</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3429
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3430<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3431
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3432<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3433<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3434 &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]3435 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3436 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3437 &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]3438</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3439
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3440<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3441<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3442
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3443<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3444<p>The two arguments to the '<tt>add</tt>' instruction must
3445 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3446 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3447
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3448<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3449<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3450
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3451<p>If the sum has unsigned overflow, the result returned is the mathematical
3452 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]3453
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3454<p>Because LLVM integers use a two's complement representation, this instruction
3455 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3456
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3457<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3458 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3459 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3460 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3461 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3462
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3463<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3464<pre>
3465 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3466</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3467
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3468</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3469
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3470<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3471<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3472 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3473</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3474
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3475<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3476
3477<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3478<pre>
3479 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3480</pre>
3481
3482<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3483<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3484
3485<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3486<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3487 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3488 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3489
3490<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3491<p>The value produced is the floating point sum of the two operands.</p>
3492
3493<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3494<pre>
3495 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3496</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3497
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3498</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3499
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3500<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3501<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3502 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3503</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3504
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3505<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3506
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3507<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3508<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3509 &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]3510 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3511 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3512 &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]3513</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3514
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3515<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3516<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3517 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3518
3519<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3520 '<tt>neg</tt>' instruction present in most other intermediate
3521 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3522
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3523<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3524<p>The two arguments to the '<tt>sub</tt>' instruction must
3525 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3526 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3527
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3528<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3529<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3530
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3531<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3532 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3533 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3534
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3535<p>Because LLVM integers use a two's complement representation, this instruction
3536 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3537
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3538<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3539 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3540 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3541 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3542 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3543
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3544<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3545<pre>
3546 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3547 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3548</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3549
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3550</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3551
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3552<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3553<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3554 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3555</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3556
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3557<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3558
3559<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3560<pre>
3561 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3562</pre>
3563
3564<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3565<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3566 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3567
3568<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3569 '<tt>fneg</tt>' instruction present in most other intermediate
3570 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3571
3572<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3573<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3574 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3575 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3576
3577<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3578<p>The value produced is the floating point difference of the two operands.</p>
3579
3580<h5>Example:</h5>
3581<pre>
3582 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3583 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3584</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3585
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3586</div>
3587
3588<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3589<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3590 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3591</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3592
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3593<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3594
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3595<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3596<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3597 &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]3598 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3599 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3600 &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]3601</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3602
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3603<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3604<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3605
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3606<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3607<p>The two arguments to the '<tt>mul</tt>' instruction must
3608 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3609 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3610
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3611<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3612<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3613
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3614<p>If the result of the multiplication has unsigned overflow, the result
3615 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3616 width of the result.</p>
3617
3618<p>Because LLVM integers use a two's complement representation, and the result
3619 is the same width as the operands, this instruction returns the correct
3620 result for both signed and unsigned integers. If a full product
3621 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3622 be sign-extended or zero-extended as appropriate to the width of the full
3623 product.</p>
3624
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3625<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3626 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3627 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3628 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3629 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3630
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3631<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3632<pre>
3633 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3634</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3635
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3636</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3637
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3638<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3639<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3640 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3641</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3642
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3643<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3644
3645<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3646<pre>
3647 &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]3648</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3649
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3650<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3651<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3652
3653<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3654<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3655 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3656 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3657
3658<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3659<p>The value produced is the floating point product of the two operands.</p>
3660
3661<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3662<pre>
3663 &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]3664</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3665
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3666</div>
3667
3668<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3669<h4>
3670 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3671</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3672
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3673<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3674
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3675<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3676<pre>
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3677 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3678 &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]3679</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3680
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3681<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3682<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3683
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3684<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3685<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3686 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3687 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3688
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3689<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3690<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3691
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3692<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3693 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3694
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3695<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3696
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3697<p>If the <tt>exact</tt> keyword is present, the result value of the
3698 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3699 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3700
3701
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3702<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3703<pre>
3704 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3705</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3706
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3707</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3708
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3709<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3710<h4>
3711 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3712</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3713
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3714<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3715
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3716<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3717<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3718 &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]3719 &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]3720</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3721
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3722<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3723<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3724
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3725<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3726<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3727 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3728 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3729
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3730<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3731<p>The value produced is the signed integer quotient of the two operands rounded
3732 towards zero.</p>
3733
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3734<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3735 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3736
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3737<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3738 undefined behavior; this is a rare case, but can occur, for example, by doing
3739 a 32-bit division of -2147483648 by -1.</p>
3740
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3741<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]3742 <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]3743 be rounded.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3744
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3745<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3746<pre>
3747 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3748</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3749
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3750</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3751
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3752<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3753<h4>
3754 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3755</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3756
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3757<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3758
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3759<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3760<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3761 &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]3762</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3763
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3764<h5>Overview:</h5>
3765<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3766
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3767<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3768<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3769 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3770 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3771
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3772<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3773<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3774
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3775<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3776<pre>
3777 &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]3778</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3779
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3780</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3781
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3782<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3783<h4>
3784 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3785</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3786
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3787<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3788
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3789<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3790<pre>
3791 &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]3792</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3793
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3794<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3795<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3796 division of its two arguments.</p>
3797
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3798<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3799<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3800 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3801 values. Both arguments must have identical types.</p>
3802
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3803<h5>Semantics:</h5>
3804<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3805 This instruction always performs an unsigned division to get the
3806 remainder.</p>
3807
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3808<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3809 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3810
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3811<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3812
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3813<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3814<pre>
3815 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3816</pre>
3817
3818</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3819
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3820<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3821<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3822 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3823</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3824
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3825<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3826
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3827<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3828<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3829 &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]3830</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3831
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3832<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3833<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3834 division of its two operands. This instruction can also take
3835 <a href="#t_vector">vector</a> versions of the values in which case the
3836 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3837
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3838<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3839<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3840 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3841 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3842
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3843<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3844<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sandsdea3a5e2011-03-07 09:12:24 +0000[diff] [blame]3845 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3846 <i>modulo</i> operator (where the result is either zero or has the same sign
3847 as the divisor, <tt>op2</tt>) of a value.
3848 For more information about the difference,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3849 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3850 Math Forum</a>. For a table of how this is implemented in various languages,
3851 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3852 Wikipedia: modulo operation</a>.</p>
3853
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3854<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3855 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3856
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3857<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3858 Overflow also leads to undefined behavior; this is a rare case, but can
3859 occur, for example, by taking the remainder of a 32-bit division of
3860 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3861 lets srem be implemented using instructions that return both the result of
3862 the division and the remainder.)</p>
3863
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3864<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3865<pre>
3866 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3867</pre>
3868
3869</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3870
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3871<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3872<h4>
3873 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3874</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3875
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3876<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3877
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3878<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3879<pre>
3880 &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]3881</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3882
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3883<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3884<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3885 its two operands.</p>
3886
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3887<h5>Arguments:</h5>
3888<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3889 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3890 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3891
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3892<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3893<p>This instruction returns the <i>remainder</i> of a division. The remainder
3894 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3895
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3896<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3897<pre>
3898 &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]3899</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3900
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3901</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3902
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3903</div>
3904
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3905<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3906<h3>
3907 <a name="bitwiseops">Bitwise Binary Operations</a>
3908</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3909
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3910<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3911
3912<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3913 program. They are generally very efficient instructions and can commonly be
3914 strength reduced from other instructions. They require two operands of the
3915 same type, execute an operation on them, and produce a single value. The
3916 resulting value is the same type as its operands.</p>
3917
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3918<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3919<h4>
3920 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3921</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3922
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3923<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3924
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3925<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3926<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3927 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3928 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3929 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3930 &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]3931</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3932
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3933<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3934<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3935 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3936
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3937<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3938<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3939 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3940 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3941
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3942<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3943<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3944 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3945 is (statically or dynamically) negative or equal to or larger than the number
3946 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3947 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3948 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3949
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3950<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3951 <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]3952 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3953 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3954 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3955 they would if the shift were expressed as a mul instruction with the same
3956 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3957
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3958<h5>Example:</h5>
3959<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3960 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3961 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3962 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3963 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3964 &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]3965</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3966
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3967</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3968
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3969<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3970<h4>
3971 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3972</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3973
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3974<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3975
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3976<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3977<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3978 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3979 &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]3980</pre>
3981
3982<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3983<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3984 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3985
3986<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3987<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3988 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3989 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3990
3991<h5>Semantics:</h5>
3992<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3993 significant bits of the result will be filled with zero bits after the shift.
3994 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3995 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3996 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3997 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3998
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3999<p>If the <tt>exact</tt> keyword is present, the result value of the
4000 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4001 shifted out are non-zero.</p>
4002
4003
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4004<h5>Example:</h5>
4005<pre>
4006 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
4007 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
4008 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
4009 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4010 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]4011 &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]4012</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4013
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4014</div>
4015
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]4016<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4017<h4>
4018 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
4019</h4>
4020
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4021<div>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4022
4023<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4024<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4025 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4026 &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]4027</pre>
4028
4029<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4030<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
4031 operand shifted to the right a specified number of bits with sign
4032 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4033
4034<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4035<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4036 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4037 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4038
4039<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4040<p>This instruction always performs an arithmetic shift right operation, The
4041 most significant bits of the result will be filled with the sign bit
4042 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
4043 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
4044 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
4045 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4046
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4047<p>If the <tt>exact</tt> keyword is present, the result value of the
4048 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4049 shifted out are non-zero.</p>
4050
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4051<h5>Example:</h5>
4052<pre>
4053 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
4054 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
4055 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
4056 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4057 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]4058 &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]4059</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4060
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4061</div>
4062
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4063<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4064<h4>
4065 <a name="i_and">'<tt>and</tt>' Instruction</a>
4066</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4067
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4068<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4069
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4070<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4071<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4072 &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]4073</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4074
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4075<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4076<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
4077 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4078
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4079<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4080<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4081 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4082 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4083
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4084<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4085<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4086
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4087<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4088 <tbody>
4089 <tr>
4090 <td>In0</td>
4091 <td>In1</td>
4092 <td>Out</td>
4093 </tr>
4094 <tr>
4095 <td>0</td>
4096 <td>0</td>
4097 <td>0</td>
4098 </tr>
4099 <tr>
4100 <td>0</td>
4101 <td>1</td>
4102 <td>0</td>
4103 </tr>
4104 <tr>
4105 <td>1</td>
4106 <td>0</td>
4107 <td>0</td>
4108 </tr>
4109 <tr>
4110 <td>1</td>
4111 <td>1</td>
4112 <td>1</td>
4113 </tr>
4114 </tbody>
4115</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4116
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4117<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4118<pre>
4119 &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]4120 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
4121 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4122</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4123</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4124<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4125<h4>
4126 <a name="i_or">'<tt>or</tt>' Instruction</a>
4127</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4128
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4129<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4130
4131<h5>Syntax:</h5>
4132<pre>
4133 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4134</pre>
4135
4136<h5>Overview:</h5>
4137<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4138 two operands.</p>
4139
4140<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4141<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4142 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4143 values. Both arguments must have identical types.</p>
4144
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4145<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4146<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4147
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4148<table border="1" cellspacing="0" cellpadding="4">
4149 <tbody>
4150 <tr>
4151 <td>In0</td>
4152 <td>In1</td>
4153 <td>Out</td>
4154 </tr>
4155 <tr>
4156 <td>0</td>
4157 <td>0</td>
4158 <td>0</td>
4159 </tr>
4160 <tr>
4161 <td>0</td>
4162 <td>1</td>
4163 <td>1</td>
4164 </tr>
4165 <tr>
4166 <td>1</td>
4167 <td>0</td>
4168 <td>1</td>
4169 </tr>
4170 <tr>
4171 <td>1</td>
4172 <td>1</td>
4173 <td>1</td>
4174 </tr>
4175 </tbody>
4176</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4177
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4178<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4179<pre>
4180 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4181 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4182 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4183</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4184
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4185</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4186
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4187<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4188<h4>
4189 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4190</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4191
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4192<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4193
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4194<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4195<pre>
4196 &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]4197</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4198
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4199<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4200<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4201 its two operands. The <tt>xor</tt> is used to implement the "one's
4202 complement" operation, which is the "~" operator in C.</p>
4203
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4204<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4205<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4206 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4207 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4208
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4209<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4210<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4211
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4212<table border="1" cellspacing="0" cellpadding="4">
4213 <tbody>
4214 <tr>
4215 <td>In0</td>
4216 <td>In1</td>
4217 <td>Out</td>
4218 </tr>
4219 <tr>
4220 <td>0</td>
4221 <td>0</td>
4222 <td>0</td>
4223 </tr>
4224 <tr>
4225 <td>0</td>
4226 <td>1</td>
4227 <td>1</td>
4228 </tr>
4229 <tr>
4230 <td>1</td>
4231 <td>0</td>
4232 <td>1</td>
4233 </tr>
4234 <tr>
4235 <td>1</td>
4236 <td>1</td>
4237 <td>0</td>
4238 </tr>
4239 </tbody>
4240</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4241
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4242<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4243<pre>
4244 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4245 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4246 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4247 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4248</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4249
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4250</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4251
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4252</div>
4253
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4254<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4255<h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4256 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4257</h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4258
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4259<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4260
4261<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4262 target-independent manner. These instructions cover the element-access and
4263 vector-specific operations needed to process vectors effectively. While LLVM
4264 does directly support these vector operations, many sophisticated algorithms
4265 will want to use target-specific intrinsics to take full advantage of a
4266 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4267
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4268<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4269<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4270 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4271</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4272
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4273<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4274
4275<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4276<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4277 &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]4278</pre>
4279
4280<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4281<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4282 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4283
4284
4285<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4286<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4287 of <a href="#t_vector">vector</a> type. The second operand is an index
4288 indicating the position from which to extract the element. The index may be
4289 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4290
4291<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4292<p>The result is a scalar of the same type as the element type of
4293 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4294 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4295 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4296
4297<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4298<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4299 &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]4300</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4301
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4302</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4303
4304<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4305<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4306 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4307</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4308
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4309<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4310
4311<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4312<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]4313 &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]4314</pre>
4315
4316<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4317<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4318 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4319
4320<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4321<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4322 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4323 whose type must equal the element type of the first operand. The third
4324 operand is an index indicating the position at which to insert the value.
4325 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4326
4327<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4328<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4329 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4330 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4331 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4332
4333<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4334<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4335 &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]4336</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4337
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4338</div>
4339
4340<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4341<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4342 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4343</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4344
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4345<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4346
4347<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4348<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4349 &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]4350</pre>
4351
4352<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4353<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4354 from two input vectors, returning a vector with the same element type as the
4355 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4356
4357<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4358<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4359 with types that match each other. The third argument is a shuffle mask whose
4360 element type is always 'i32'. The result of the instruction is a vector
4361 whose length is the same as the shuffle mask and whose element type is the
4362 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4363
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4364<p>The shuffle mask operand is required to be a constant vector with either
4365 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4366
4367<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4368<p>The elements of the two input vectors are numbered from left to right across
4369 both of the vectors. The shuffle mask operand specifies, for each element of
4370 the result vector, which element of the two input vectors the result element
4371 gets. The element selector may be undef (meaning "don't care") and the
4372 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4373
4374<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4375<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4376 &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]4377 &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]4378 &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]4379 &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]4380 &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]4381 &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]4382 &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]4383 &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]4384</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4385
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4386</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]4387
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4388</div>
4389
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4390<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4391<h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4392 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4393</h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4394
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4395<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4396
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4397<p>LLVM supports several instructions for working with
4398 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4399
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4400<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4401<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4402 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4403</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4404
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4405<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4406
4407<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4408<pre>
4409 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4410</pre>
4411
4412<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4413<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4414 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4415
4416<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4417<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4418 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4419 <a href="#t_array">array</a> type. The operands are constant indices to
4420 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4421 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4422 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4423 <ul>
4424 <li>Since the value being indexed is not a pointer, the first index is
4425 omitted and assumed to be zero.</li>
4426 <li>At least one index must be specified.</li>
4427 <li>Not only struct indices but also array indices must be in
4428 bounds.</li>
4429 </ul>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4430
4431<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4432<p>The result is the value at the position in the aggregate specified by the
4433 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4434
4435<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4436<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4437 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4438</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4439
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4440</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4441
4442<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4443<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4444 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4445</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4446
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4447<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4448
4449<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4450<pre>
Bill Wendling194229e2011-07-26 20:42:28 +0000[diff] [blame]4451 &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]4452</pre>
4453
4454<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4455<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4456 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4457
4458<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4459<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4460 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4461 <a href="#t_array">array</a> type. The second operand is a first-class
4462 value to insert. The following operands are constant indices indicating
4463 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]4464 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4465 value to insert must have the same type as the value identified by the
4466 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4467
4468<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4469<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4470 that of <tt>val</tt> except that the value at the position specified by the
4471 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4472
4473<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4474<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame]4475 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4476 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4477 %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]4478</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4479
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4480</div>
4481
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4482</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4483
4484<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4485<h3>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4486 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4487</h3>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4488
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4489<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4490
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4491<p>A key design point of an SSA-based representation is how it represents
4492 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4493 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4494 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4495
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4496<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4497<h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4498 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4499</h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4500
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4501<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4502
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4503<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4504<pre>
Dan Gohmanf75a7d32010-05-28 01:14:11 +0000[diff] [blame]4505 &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]4506</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4507
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4508<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4509<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4510 currently executing function, to be automatically released when this function
4511 returns to its caller. The object is always allocated in the generic address
4512 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4513
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4514<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4515<p>The '<tt>alloca</tt>' instruction
4516 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4517 runtime stack, returning a pointer of the appropriate type to the program.
4518 If "NumElements" is specified, it is the number of elements allocated,
4519 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4520 specified, the value result of the allocation is guaranteed to be aligned to
4521 at least that boundary. If not specified, or if zero, the target can choose
4522 to align the allocation on any convenient boundary compatible with the
4523 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4524
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4525<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4526
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4527<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4528<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4529 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4530 memory is automatically released when the function returns. The
4531 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4532 variables that must have an address available. When the function returns
4533 (either with the <tt><a href="#i_ret">ret</a></tt>
4534 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4535 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4536
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4537<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4538<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4539 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4540 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4541 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4542 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4543</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4544
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4545</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4546
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4547<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4548<h4>
4549 <a name="i_load">'<tt>load</tt>' Instruction</a>
4550</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4551
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4552<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4553
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4554<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4555<pre>
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4556 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4557 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4558 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4559</pre>
4560
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4561<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4562<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4563
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4564<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4565<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4566 from which to load. The pointer must point to
4567 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4568 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4569 number or order of execution of this <tt>load</tt> with other <a
4570 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4571
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4572<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4573 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]4574 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4575 alignment for the target. It is the responsibility of the code emitter to
4576 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4577 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4578 produce less efficient code. An alignment of 1 is always safe.</p>
4579
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4580<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4581 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4582 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4583 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4584 and code generator that this load is not expected to be reused in the cache.
4585 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4586 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4587
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4588<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4589<p>The location of memory pointed to is loaded. If the value being loaded is of
4590 scalar type then the number of bytes read does not exceed the minimum number
4591 of bytes needed to hold all bits of the type. For example, loading an
4592 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4593 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4594 is undefined if the value was not originally written using a store of the
4595 same type.</p>
4596
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4597<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4598<pre>
4599 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4600 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4601 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4602</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4603
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4604</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4605
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4606<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4607<h4>
4608 <a name="i_store">'<tt>store</tt>' Instruction</a>
4609</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4610
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4611<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4612
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4613<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4614<pre>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4615 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>
4616 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>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4617</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4618
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4619<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4620<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4621
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4622<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4623<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4624 and an address at which to store it. The type of the
4625 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4626 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4627 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4628 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4629 order of execution of this <tt>store</tt> with other <a
4630 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4631
4632<p>The optional constant "align" argument specifies the alignment of the
4633 operation (that is, the alignment of the memory address). A value of 0 or an
4634 omitted "align" argument means that the operation has the preferential
4635 alignment for the target. It is the responsibility of the code emitter to
4636 ensure that the alignment information is correct. Overestimating the
4637 alignment results in an undefined behavior. Underestimating the alignment may
4638 produce less efficient code. An alignment of 1 is always safe.</p>
4639
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4640<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4641 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4642 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4643 instruction tells the optimizer and code generator that this load is
4644 not expected to be reused in the cache. The code generator may
4645 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4646 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4647
4648
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4649<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4650<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4651 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4652 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4653 does not exceed the minimum number of bytes needed to hold all bits of the
4654 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4655 writing a value of a type like <tt>i20</tt> with a size that is not an
4656 integral number of bytes, it is unspecified what happens to the extra bits
4657 that do not belong to the type, but they will typically be overwritten.</p>
4658
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4659<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4660<pre>
4661 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4662 store i32 3, i32* %ptr <i>; yields {void}</i>
4663 %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]4664</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4665
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4666</div>
4667
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4668<!-- _______________________________________________________________________ -->
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame]4669<div class="doc_subsubsection"> <a name="i_fence">'<tt>fence</tt>'
4670Instruction</a> </div>
4671
4672<div class="doc_text">
4673
4674<h5>Syntax:</h5>
4675<pre>
4676 fence [singlethread] &lt;ordering&gt; <i>; yields {void}</i>
4677</pre>
4678
4679<h5>Overview:</h5>
4680<p>The '<tt>fence</tt>' instruction is used to introduce happens-before edges
4681between operations.</p>
4682
4683<h5>Arguments:</h5> <p>'<code>fence</code>' instructions take an <a
4684href="#ordering">ordering</a> argument which defines what
4685<i>synchronizes-with</i> edges they add. They can only be given
4686<code>acquire</code>, <code>release</code>, <code>acq_rel</code>, and
4687<code>seq_cst</code> orderings.</p>
4688
4689<h5>Semantics:</h5>
4690<p>A fence <var>A</var> which has (at least) <code>release</code> ordering
4691semantics <i>synchronizes with</i> a fence <var>B</var> with (at least)
4692<code>acquire</code> ordering semantics if and only if there exist atomic
4693operations <var>X</var> and <var>Y</var>, both operating on some atomic object
4694<var>M</var>, such that <var>A</var> is sequenced before <var>X</var>,
4695<var>X</var> modifies <var>M</var> (either directly or through some side effect
4696of a sequence headed by <var>X</var>), <var>Y</var> is sequenced before
4697<var>B</var>, and <var>Y</var> observes <var>M</var>. This provides a
4698<i>happens-before</i> dependency between <var>A</var> and <var>B</var>. Rather
4699than an explicit <code>fence</code>, one (but not both) of the atomic operations
4700<var>X</var> or <var>Y</var> might provide a <code>release</code> or
4701<code>acquire</code> (resp.) ordering constraint and still
4702<i>synchronize-with</i> the explicit <code>fence</code> and establish the
4703<i>happens-before</i> edge.</p>
4704
4705<p>A <code>fence</code> which has <code>seq_cst</code> ordering, in addition to
4706having both <code>acquire</code> and <code>release</code> semantics specified
4707above, participates in the global program order of other <code>seq_cst</code>
4708operations and/or fences.</p>
4709
4710<p>The optional "<a href="#singlethread"><code>singlethread</code></a>" argument
4711specifies that the fence only synchronizes with other fences in the same
4712thread. (This is useful for interacting with signal handlers.)</p>
4713
4714<p>FIXME: This instruction is a work in progress; until it is finished, use
4715 llvm.memory.barrier.
4716
4717<h5>Example:</h5>
4718<pre>
4719 fence acquire <i>; yields {void}</i>
4720 fence singlethread seq_cst <i>; yields {void}</i>
4721</pre>
4722
4723</div>
4724
4725<!-- _______________________________________________________________________ -->
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame^]4726<div class="doc_subsubsection"> <a name="i_cmpxchg">'<tt>cmpxchg</tt>'
4727Instruction</a> </div>
4728
4729<div class="doc_text">
4730
4731<h5>Syntax:</h5>
4732<pre>
4733 [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>
4734</pre>
4735
4736<h5>Overview:</h5>
4737<p>The '<tt>cmpxchg</tt>' instruction is used to atomically modify memory.
4738It loads a value in memory and compares it to a given value. If they are
4739equal, it stores a new value into the memory.</p>
4740
4741<h5>Arguments:</h5>
4742<p>There are three arguments to the '<code>cmpxchg</code>' instruction: an
4743address to operate on, a value to compare to the value currently be at that
4744address, and a new value to place at that address if the compared values are
4745equal. The type of '<var>&lt;cmp&gt;</var>' must be an integer type whose
4746bit width is a power of two greater than or equal to eight and less than
4747or equal to a target-specific size limit. '<var>&lt;cmp&gt;</var>' and
4748'<var>&lt;new&gt;</var>' must have the same type, and the type of
4749'<var>&lt;pointer&gt;</var>' must be a pointer to that type. If the
4750<code>cmpxchg</code> is marked as <code>volatile</code>, then the
4751optimizer is not allowed to modify the number or order of execution
4752of this <code>cmpxchg</code> with other <a href="#volatile">volatile
4753operations</a>.</p>
4754
4755<!-- FIXME: Extend allowed types. -->
4756
4757<p>The <a href="#ordering"><var>ordering</var></a> argument specifies how this
4758<code>cmpxchg</code> synchronizes with other atomic operations.</p>
4759
4760<p>The optional "<code>singlethread</code>" argument declares that the
4761<code>cmpxchg</code> is only atomic with respect to code (usually signal
4762handlers) running in the same thread as the <code>cmpxchg</code>. Otherwise the
4763cmpxchg is atomic with respect to all other code in the system.</p>
4764
4765<p>The pointer passed into cmpxchg must have alignment greater than or equal to
4766the size in memory of the operand.
4767
4768<h5>Semantics:</h5>
4769<p>The contents of memory at the location specified by the
4770'<tt>&lt;pointer&gt;</tt>' operand is read and compared to
4771'<tt>&lt;cmp&gt;</tt>'; if the read value is the equal,
4772'<tt>&lt;new&gt;</tt>' is written. The original value at the location
4773is returned.
4774
4775<p>A successful <code>cmpxchg</code> is a read-modify-write instruction for the
4776purpose of identifying <a href="#release_sequence">release sequences</a>. A
4777failed <code>cmpxchg</code> is equivalent to an atomic load with an ordering
4778parameter determined by dropping any <code>release</code> part of the
4779<code>cmpxchg</code>'s ordering.</p>
4780
4781<!--
4782FIXME: Is compare_exchange_weak() necessary? (Consider after we've done
4783optimization work on ARM.)
4784
4785FIXME: Is a weaker ordering constraint on failure helpful in practice?
4786-->
4787
4788<h5>Example:</h5>
4789<pre>
4790entry:
4791 %orig = atomic <a href="#i_load">load</a> i32* %ptr unordered <i>; yields {i32}</i>
4792 <a href="#i_br">br</a> label %loop
4793
4794loop:
4795 %cmp = <a href="#i_phi">phi</a> i32 [ %orig, %entry ], [%old, %loop]
4796 %squared = <a href="#i_mul">mul</a> i32 %cmp, %cmp
4797 %old = cmpxchg i32* %ptr, i32 %cmp, i32 %squared <i>; yields {i32}</i>
4798 %success = <a href="#i_icmp">icmp</a> eq i32 %cmp, %old
4799 <a href="#i_br">br</a> i1 %success, label %done, label %loop
4800
4801done:
4802 ...
4803</pre>
4804
4805</div>
4806
4807<!-- _______________________________________________________________________ -->
4808<div class="doc_subsubsection"> <a name="i_atomicrmw">'<tt>atomicrmw</tt>'
4809Instruction</a> </div>
4810
4811<div class="doc_text">
4812
4813<h5>Syntax:</h5>
4814<pre>
4815 [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>
4816</pre>
4817
4818<h5>Overview:</h5>
4819<p>The '<tt>atomicrmw</tt>' instruction is used to atomically modify memory.</p>
4820
4821<h5>Arguments:</h5>
4822<p>There are three arguments to the '<code>atomicrmw</code>' instruction: an
4823operation to apply, an address whose value to modify, an argument to the
4824operation. The operation must be one of the following keywords:</p>
4825<ul>
4826 <li>xchg</li>
4827 <li>add</li>
4828 <li>sub</li>
4829 <li>and</li>
4830 <li>nand</li>
4831 <li>or</li>
4832 <li>xor</li>
4833 <li>max</li>
4834 <li>min</li>
4835 <li>umax</li>
4836 <li>umin</li>
4837</ul>
4838
4839<p>The type of '<var>&lt;value&gt;</var>' must be an integer type whose
4840bit width is a power of two greater than or equal to eight and less than
4841or equal to a target-specific size limit. The type of the
4842'<code>&lt;pointer&gt;</code>' operand must be a pointer to that type.
4843If the <code>atomicrmw</code> is marked as <code>volatile</code>, then the
4844optimizer is not allowed to modify the number or order of execution of this
4845<code>atomicrmw</code> with other <a href="#volatile">volatile
4846 operations</a>.</p>
4847
4848<!-- FIXME: Extend allowed types. -->
4849
4850<h5>Semantics:</h5>
4851<p>The contents of memory at the location specified by the
4852'<tt>&lt;pointer&gt;</tt>' operand are atomically read, modified, and written
4853back. The original value at the location is returned. The modification is
4854specified by the <var>operation</var> argument:</p>
4855
4856<ul>
4857 <li>xchg: <code>*ptr = val</code></li>
4858 <li>add: <code>*ptr = *ptr + val</code></li>
4859 <li>sub: <code>*ptr = *ptr - val</code></li>
4860 <li>and: <code>*ptr = *ptr &amp; val</code></li>
4861 <li>nand: <code>*ptr = ~(*ptr &amp; val)</code></li>
4862 <li>or: <code>*ptr = *ptr | val</code></li>
4863 <li>xor: <code>*ptr = *ptr ^ val</code></li>
4864 <li>max: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using a signed comparison)</li>
4865 <li>min: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using a signed comparison)</li>
4866 <li>umax: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4867 <li>umin: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4868</ul>
4869
4870<h5>Example:</h5>
4871<pre>
4872 %old = atomicrmw add i32* %ptr, i32 1 acquire <i>; yields {i32}</i>
4873</pre>
4874
4875</div>
4876
4877<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4878<h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4879 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4880</h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4881
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4882<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4883
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4884<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4885<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4886 &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]4887 &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]4888</pre>
4889
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4890<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4891<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4892 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4893 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4894
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4895<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4896<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4897 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4898 elements of the aggregate object are indexed. The interpretation of each
4899 index is dependent on the type being indexed into. The first index always
4900 indexes the pointer value given as the first argument, the second index
4901 indexes a value of the type pointed to (not necessarily the value directly
4902 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4903 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4904 vectors, and structs. Note that subsequent types being indexed into
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4905 can never be pointers, since that would require loading the pointer before
4906 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4907
4908<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]4909 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4910 integer <b>constants</b> are allowed. When indexing into an array, pointer
4911 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]4912 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4913
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4914<p>For example, let's consider a C code fragment and how it gets compiled to
4915 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4916
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4917<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4918struct RT {
4919 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4920 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4921 char C;
4922};
4923struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4924 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4925 double Y;
4926 struct RT Z;
4927};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4928
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4929int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4930 return &amp;s[1].Z.B[5][13];
4931}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4932</pre>
4933
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4934<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4935
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4936<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]4937%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4938%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4939
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4940define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4941entry:
4942 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4943 ret i32* %reg
4944}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4945</pre>
4946
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4947<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4948<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]4949 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4950 }</tt>' type, a structure. The second index indexes into the third element
4951 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4952 i8 }</tt>' type, another structure. The third index indexes into the second
4953 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4954 array. The two dimensions of the array are subscripted into, yielding an
4955 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4956 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4957
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4958<p>Note that it is perfectly legal to index partially through a structure,
4959 returning a pointer to an inner element. Because of this, the LLVM code for
4960 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4961
4962<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4963 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4964 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4965 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4966 %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]4967 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4968 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4969 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4970 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4971</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]4972
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4973<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]4974 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4975 base pointer is not an <i>in bounds</i> address of an allocated object,
4976 or if any of the addresses that would be formed by successive addition of
4977 the offsets implied by the indices to the base address with infinitely
4978 precise arithmetic are not an <i>in bounds</i> address of that allocated
4979 object. The <i>in bounds</i> addresses for an allocated object are all
4980 the addresses that point into the object, plus the address one byte past
4981 the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4982
4983<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4984 the base address with silently-wrapping two's complement arithmetic, and
4985 the result value of the <tt>getelementptr</tt> may be outside the object
4986 pointed to by the base pointer. The result value may not necessarily be
4987 used to access memory though, even if it happens to point into allocated
4988 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4989 section for more information.</p>
4990
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4991<p>The getelementptr instruction is often confusing. For some more insight into
4992 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4993
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4994<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4995<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4996 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4997 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4998 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4999 %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]5000 <i>; yields i8*:eptr</i>
5001 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]5002 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]5003 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5004</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5005
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5006</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]5007
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5008</div>
5009
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5010<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5011<h3>
5012 <a name="convertops">Conversion Operations</a>
5013</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5014
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5015<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5016
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5017<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5018 which all take a single operand and a type. They perform various bit
5019 conversions on the operand.</p>
5020
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5021<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5022<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5023 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5024</h4>
5025
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5026<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5027
5028<h5>Syntax:</h5>
5029<pre>
5030 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5031</pre>
5032
5033<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5034<p>The '<tt>trunc</tt>' instruction truncates its operand to the
5035 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5036
5037<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5038<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
5039 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5040 of the same number of integers.
5041 The bit size of the <tt>value</tt> must be larger than
5042 the bit size of the destination type, <tt>ty2</tt>.
5043 Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5044
5045<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5046<p>The '<tt>trunc</tt>' instruction truncates the high order bits
5047 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
5048 source size must be larger than the destination size, <tt>trunc</tt> cannot
5049 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5050
5051<h5>Example:</h5>
5052<pre>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5053 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
5054 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
5055 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
5056 %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]5057</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5058
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5059</div>
5060
5061<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5062<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5063 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5064</h4>
5065
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5066<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5067
5068<h5>Syntax:</h5>
5069<pre>
5070 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5071</pre>
5072
5073<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5074<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5075 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5076
5077
5078<h5>Arguments:</h5>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]5079<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
5080 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5081 of the same number of integers.
5082 The bit size of the <tt>value</tt> must be smaller than
5083 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5084 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5085
5086<h5>Semantics:</h5>
5087<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]5088 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5089
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]5090<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]5091
5092<h5>Example:</h5>
5093<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5094 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5095 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]5096 %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]5097</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5098
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5099</div>
5100
5101<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5102<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5103 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5104</h4>
5105
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5106<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5107
5108<h5>Syntax:</h5>
5109<pre>
5110 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5111</pre>
5112
5113<h5>Overview:</h5>
5114<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
5115
5116<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5117<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
5118 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5119 of the same number of integers.
5120 The bit size of the <tt>value</tt> must be smaller than
5121 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5122 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5123
5124<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5125<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
5126 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
5127 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5128
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5129<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]5130
5131<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5132<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5133 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5134 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5135 %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]5136</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5137
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5138</div>
5139
5140<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5141<h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5142 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5143</h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5144
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5145<div>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5146
5147<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5148<pre>
5149 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5150</pre>
5151
5152<h5>Overview:</h5>
5153<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5154 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5155
5156<h5>Arguments:</h5>
5157<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5158 point</a> value to cast and a <a href="#t_floating">floating point</a> type
5159 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]5160 <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]5161 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5162
5163<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5164<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5165 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5166 <a href="#t_floating">floating point</a> type. If the value cannot fit
5167 within the destination type, <tt>ty2</tt>, then the results are
5168 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5169
5170<h5>Example:</h5>
5171<pre>
5172 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
5173 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
5174</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5175
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5176</div>
5177
5178<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5179<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5180 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5181</h4>
5182
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5183<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5184
5185<h5>Syntax:</h5>
5186<pre>
5187 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5188</pre>
5189
5190<h5>Overview:</h5>
5191<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]5192 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5193
5194<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5195<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5196 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
5197 a <a href="#t_floating">floating point</a> type to cast it to. The source
5198 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5199
5200<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5201<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5202 <a href="#t_floating">floating point</a> type to a larger
5203 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
5204 used to make a <i>no-op cast</i> because it always changes bits. Use
5205 <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]5206
5207<h5>Example:</h5>
5208<pre>
Nick Lewycky5bb3ece2011-03-31 18:20:19 +0000[diff] [blame]5209 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
5210 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5211</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5212
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5213</div>
5214
5215<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5216<h4>
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]5217 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5218</h4>
5219
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5220<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5221
5222<h5>Syntax:</h5>
5223<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5224 &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]5225</pre>
5226
5227<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5228<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5229 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5230
5231<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5232<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
5233 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5234 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5235 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5236 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5237
5238<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5239<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5240 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5241 towards zero) unsigned integer value. If the value cannot fit
5242 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5243
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5244<h5>Example:</h5>
5245<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5246 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]5247 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5248 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5249</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5250
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5251</div>
5252
5253<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5254<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5255 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5256</h4>
5257
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5258<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5259
5260<h5>Syntax:</h5>
5261<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5262 &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]5263</pre>
5264
5265<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5266<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5267 <a href="#t_floating">floating point</a> <tt>value</tt> to
5268 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5269
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5270<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5271<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
5272 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5273 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5274 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5275 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5276
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5277<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5278<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5279 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5280 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
5281 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5282
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]5283<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5284<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5285 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]5286 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5287 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5288</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5289
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5290</div>
5291
5292<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5293<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5294 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5295</h4>
5296
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5297<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5298
5299<h5>Syntax:</h5>
5300<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5301 &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]5302</pre>
5303
5304<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5305<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5306 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5307
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5308<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5309<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]5310 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5311 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5312 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5313 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5314
5315<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5316<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5317 integer quantity and converts it to the corresponding floating point
5318 value. If the value cannot fit in the floating point value, the results are
5319 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5320
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5321<h5>Example:</h5>
5322<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5323 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5324 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5325</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5326
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5327</div>
5328
5329<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5330<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5331 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5332</h4>
5333
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5334<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5335
5336<h5>Syntax:</h5>
5337<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5338 &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]5339</pre>
5340
5341<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5342<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5343 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5344
5345<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5346<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]5347 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5348 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5349 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5350 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5351
5352<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5353<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5354 quantity and converts it to the corresponding floating point value. If the
5355 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5356
5357<h5>Example:</h5>
5358<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5359 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5360 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5361</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5362
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5363</div>
5364
5365<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5366<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5367 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5368</h4>
5369
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5370<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5371
5372<h5>Syntax:</h5>
5373<pre>
5374 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5375</pre>
5376
5377<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5378<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5379 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5380
5381<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5382<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5383 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5384 <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]5385
5386<h5>Semantics:</h5>
5387<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5388 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5389 truncating or zero extending that value to the size of the integer type. If
5390 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5391 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5392 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5393 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5394
5395<h5>Example:</h5>
5396<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5397 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5398 %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]5399</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5400
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5401</div>
5402
5403<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5404<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5405 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5406</h4>
5407
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5408<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5409
5410<h5>Syntax:</h5>
5411<pre>
5412 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5413</pre>
5414
5415<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5416<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5417 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5418
5419<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]5420<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5421 value to cast, and a type to cast it to, which must be a
5422 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5423
5424<h5>Semantics:</h5>
5425<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5426 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5427 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5428 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5429 than the size of a pointer then a zero extension is done. If they are the
5430 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5431
5432<h5>Example:</h5>
5433<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5434 %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]5435 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5436 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5437</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5438
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5439</div>
5440
5441<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5442<h4>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5443 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5444</h4>
5445
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5446<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5447
5448<h5>Syntax:</h5>
5449<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5450 &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]5451</pre>
5452
5453<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5454<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5455 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5456
5457<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5458<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5459 non-aggregate first class value, and a type to cast it to, which must also be
5460 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5461 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5462 identical. If the source type is a pointer, the destination type must also be
5463 a pointer. This instruction supports bitwise conversion of vectors to
5464 integers and to vectors of other types (as long as they have the same
5465 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5466
5467<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5468<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5469 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5470 this conversion. The conversion is done as if the <tt>value</tt> had been
5471 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5472 be converted to other pointer types with this instruction. To convert
5473 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5474 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5475
5476<h5>Example:</h5>
5477<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5478 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5479 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5480 %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]5481</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5482
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5483</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5484
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5485</div>
5486
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5487<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5488<h3>
5489 <a name="otherops">Other Operations</a>
5490</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5491
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5492<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5493
5494<p>The instructions in this category are the "miscellaneous" instructions, which
5495 defy better classification.</p>
5496
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5497<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5498<h4>
5499 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5500</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5501
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5502<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5503
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5504<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5505<pre>
5506 &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]5507</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5508
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5509<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5510<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5511 boolean values based on comparison of its two integer, integer vector, or
5512 pointer operands.</p>
5513
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5514<h5>Arguments:</h5>
5515<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5516 the condition code indicating the kind of comparison to perform. It is not a
5517 value, just a keyword. The possible condition code are:</p>
5518
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5519<ol>
5520 <li><tt>eq</tt>: equal</li>
5521 <li><tt>ne</tt>: not equal </li>
5522 <li><tt>ugt</tt>: unsigned greater than</li>
5523 <li><tt>uge</tt>: unsigned greater or equal</li>
5524 <li><tt>ult</tt>: unsigned less than</li>
5525 <li><tt>ule</tt>: unsigned less or equal</li>
5526 <li><tt>sgt</tt>: signed greater than</li>
5527 <li><tt>sge</tt>: signed greater or equal</li>
5528 <li><tt>slt</tt>: signed less than</li>
5529 <li><tt>sle</tt>: signed less or equal</li>
5530</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5531
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]5532<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5533 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5534 typed. They must also be identical types.</p>
5535
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5536<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5537<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5538 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5539 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]5540 result, as follows:</p>
5541
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5542<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5543 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5544 <tt>false</tt> otherwise. No sign interpretation is necessary or
5545 performed.</li>
5546
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5547 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5548 <tt>false</tt> otherwise. No sign interpretation is necessary or
5549 performed.</li>
5550
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5551 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5552 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5553
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5554 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5555 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5556 to <tt>op2</tt>.</li>
5557
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5558 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5559 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5560
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5561 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5562 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5563
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5564 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5565 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5566
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5567 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5568 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5569 to <tt>op2</tt>.</li>
5570
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5571 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5572 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5573
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5574 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5575 <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]5576</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5577
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5578<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5579 values are compared as if they were integers.</p>
5580
5581<p>If the operands are integer vectors, then they are compared element by
5582 element. The result is an <tt>i1</tt> vector with the same number of elements
5583 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5584
5585<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5586<pre>
5587 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5588 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5589 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5590 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5591 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5592 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5593</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5594
5595<p>Note that the code generator does not yet support vector types with
5596 the <tt>icmp</tt> instruction.</p>
5597
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5598</div>
5599
5600<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5601<h4>
5602 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5603</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5604
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5605<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5606
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5607<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5608<pre>
5609 &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]5610</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5611
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5612<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5613<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5614 values based on comparison of its operands.</p>
5615
5616<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]5617(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5618
5619<p>If the operands are floating point vectors, then the result type is a vector
5620 of boolean with the same number of elements as the operands being
5621 compared.</p>
5622
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5623<h5>Arguments:</h5>
5624<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5625 the condition code indicating the kind of comparison to perform. It is not a
5626 value, just a keyword. The possible condition code are:</p>
5627
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5628<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5629 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5630 <li><tt>oeq</tt>: ordered and equal</li>
5631 <li><tt>ogt</tt>: ordered and greater than </li>
5632 <li><tt>oge</tt>: ordered and greater than or equal</li>
5633 <li><tt>olt</tt>: ordered and less than </li>
5634 <li><tt>ole</tt>: ordered and less than or equal</li>
5635 <li><tt>one</tt>: ordered and not equal</li>
5636 <li><tt>ord</tt>: ordered (no nans)</li>
5637 <li><tt>ueq</tt>: unordered or equal</li>
5638 <li><tt>ugt</tt>: unordered or greater than </li>
5639 <li><tt>uge</tt>: unordered or greater than or equal</li>
5640 <li><tt>ult</tt>: unordered or less than </li>
5641 <li><tt>ule</tt>: unordered or less than or equal</li>
5642 <li><tt>une</tt>: unordered or not equal</li>
5643 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5644 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5645</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5646
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5647<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5648 <i>unordered</i> means that either operand may be a QNAN.</p>
5649
5650<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5651 a <a href="#t_floating">floating point</a> type or
5652 a <a href="#t_vector">vector</a> of floating point type. They must have
5653 identical types.</p>
5654
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5655<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]5656<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5657 according to the condition code given as <tt>cond</tt>. If the operands are
5658 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5659 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5660 follows:</p>
5661
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5662<ol>
5663 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5664
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5665 <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]5666 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5667
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5668 <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]5669 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5670
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5671 <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]5672 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5673
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5674 <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]5675 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5676
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5677 <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]5678 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5679
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5680 <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]5681 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5682
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5683 <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]5684
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5685 <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]5686 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5687
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5688 <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]5689 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5690
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5691 <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]5692 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5693
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5694 <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]5695 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5696
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5697 <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]5698 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5699
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5700 <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]5701 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5702
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5703 <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]5704
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5705 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5706</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5707
5708<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5709<pre>
5710 &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]5711 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5712 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5713 &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]5714</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5715
5716<p>Note that the code generator does not yet support vector types with
5717 the <tt>fcmp</tt> instruction.</p>
5718
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5719</div>
5720
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5721<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5722<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5723 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5724</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5725
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5726<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5727
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5728<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5729<pre>
5730 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5731</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5732
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5733<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5734<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5735 SSA graph representing the function.</p>
5736
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5737<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5738<p>The type of the incoming values is specified with the first type field. After
5739 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5740 one pair for each predecessor basic block of the current block. Only values
5741 of <a href="#t_firstclass">first class</a> type may be used as the value
5742 arguments to the PHI node. Only labels may be used as the label
5743 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5744
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5745<p>There must be no non-phi instructions between the start of a basic block and
5746 the PHI instructions: i.e. PHI instructions must be first in a basic
5747 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5748
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5749<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5750 occur on the edge from the corresponding predecessor block to the current
5751 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5752 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]5753
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5754<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5755<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5756 specified by the pair corresponding to the predecessor basic block that
5757 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5758
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5759<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5760<pre>
5761Loop: ; Infinite loop that counts from 0 on up...
5762 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5763 %nextindvar = add i32 %indvar, 1
5764 br label %Loop
5765</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5766
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5767</div>
5768
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5769<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5770<h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5771 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5772</h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5773
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5774<div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5775
5776<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5777<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5778 &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>
5779
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5780 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5781</pre>
5782
5783<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5784<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5785 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5786
5787
5788<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5789<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5790 values indicating the condition, and two values of the
5791 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5792 vectors and the condition is a scalar, then entire vectors are selected, not
5793 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5794
5795<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5796<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5797 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5798
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5799<p>If the condition is a vector of i1, then the value arguments must be vectors
5800 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5801
5802<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5803<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5804 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5805</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5806
5807<p>Note that the code generator does not yet support conditions
5808 with vector type.</p>
5809
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5810</div>
5811
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5812<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5813<h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5814 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5815</h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5816
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5817<div>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5818
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5819<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5820<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]5821 &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]5822</pre>
5823
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5824<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5825<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5826
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5827<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5828<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5829
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5830<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5831 <li>The optional "tail" marker indicates that the callee function does not
5832 access any allocas or varargs in the caller. Note that calls may be
5833 marked "tail" even if they do not occur before
5834 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5835 present, the function call is eligible for tail call optimization,
5836 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Chengdc444e92010-03-08 21:05:02 +0000[diff] [blame]5837 optimized into a jump</a>. The code generator may optimize calls marked
5838 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5839 sibling call optimization</a> when the caller and callee have
5840 matching signatures, or 2) forced tail call optimization when the
5841 following extra requirements are met:
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5842 <ul>
5843 <li>Caller and callee both have the calling
5844 convention <tt>fastcc</tt>.</li>
5845 <li>The call is in tail position (ret immediately follows call and ret
5846 uses value of call or is void).</li>
5847 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohmanfbbee8d2010-03-02 01:08:11 +0000[diff] [blame]5848 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5849 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5850 constraints are met.</a></li>
5851 </ul>
5852 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5853
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5854 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5855 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5856 defaults to using C calling conventions. The calling convention of the
5857 call must match the calling convention of the target function, or else the
5858 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5859
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5860 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5861 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5862 '<tt>inreg</tt>' attributes are valid here.</li>
5863
5864 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5865 type of the return value. Functions that return no value are marked
5866 <tt><a href="#t_void">void</a></tt>.</li>
5867
5868 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5869 being invoked. The argument types must match the types implied by this
5870 signature. This type can be omitted if the function is not varargs and if
5871 the function type does not return a pointer to a function.</li>
5872
5873 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5874 be invoked. In most cases, this is a direct function invocation, but
5875 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5876 to function value.</li>
5877
5878 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]5879 signature argument types and parameter attributes. All arguments must be
5880 of <a href="#t_firstclass">first class</a> type. If the function
5881 signature indicates the function accepts a variable number of arguments,
5882 the extra arguments can be specified.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5883
5884 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5885 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5886 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5887</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5888
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5889<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5890<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5891 a specified function, with its incoming arguments bound to the specified
5892 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5893 function, control flow continues with the instruction after the function
5894 call, and the return value of the function is bound to the result
5895 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5896
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5897<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5898<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]5899 %retval = call i32 @test(i32 %argc)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]5900 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]5901 %X = tail call i32 @foo() <i>; yields i32</i>
5902 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5903 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]5904
5905 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5906 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]5907 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5908 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]5909 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]5910 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5911</pre>
5912
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5913<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]5914standard C99 library as being the C99 library functions, and may perform
5915optimizations or generate code for them under that assumption. This is
5916something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5917freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5918
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5919</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5920
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5921<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5922<h4>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]5923 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5924</h4>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5925
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5926<div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5927
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5928<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5929<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5930 &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]5931</pre>
5932
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5933<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5934<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5935 the "variable argument" area of a function call. It is used to implement the
5936 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5937
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5938<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5939<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5940 argument. It returns a value of the specified argument type and increments
5941 the <tt>va_list</tt> to point to the next argument. The actual type
5942 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5943
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5944<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5945<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5946 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5947 to the next argument. For more information, see the variable argument
5948 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5949
5950<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]5951 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5952 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5953
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5954<p><tt>va_arg</tt> is an LLVM instruction instead of
5955 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5956 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5957
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5958<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5959<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5960
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5961<p>Note that the code generator does not yet fully support va_arg on many
5962 targets. Also, it does not currently support va_arg with aggregate types on
5963 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]5964
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5965</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5966
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5967</div>
5968
5969</div>
5970
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5971<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5972<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]5973<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5974
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5975<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5976
5977<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5978 well known names and semantics and are required to follow certain
5979 restrictions. Overall, these intrinsics represent an extension mechanism for
5980 the LLVM language that does not require changing all of the transformations
5981 in LLVM when adding to the language (or the bitcode reader/writer, the
5982 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5983
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5984<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5985 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5986 begin with this prefix. Intrinsic functions must always be external
5987 functions: you cannot define the body of intrinsic functions. Intrinsic
5988 functions may only be used in call or invoke instructions: it is illegal to
5989 take the address of an intrinsic function. Additionally, because intrinsic
5990 functions are part of the LLVM language, it is required if any are added that
5991 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5992
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5993<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5994 family of functions that perform the same operation but on different data
5995 types. Because LLVM can represent over 8 million different integer types,
5996 overloading is used commonly to allow an intrinsic function to operate on any
5997 integer type. One or more of the argument types or the result type can be
5998 overloaded to accept any integer type. Argument types may also be defined as
5999 exactly matching a previous argument's type or the result type. This allows
6000 an intrinsic function which accepts multiple arguments, but needs all of them
6001 to be of the same type, to only be overloaded with respect to a single
6002 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6003
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6004<p>Overloaded intrinsics will have the names of its overloaded argument types
6005 encoded into its function name, each preceded by a period. Only those types
6006 which are overloaded result in a name suffix. Arguments whose type is matched
6007 against another type do not. For example, the <tt>llvm.ctpop</tt> function
6008 can take an integer of any width and returns an integer of exactly the same
6009 integer width. This leads to a family of functions such as
6010 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
6011 %val)</tt>. Only one type, the return type, is overloaded, and only one type
6012 suffix is required. Because the argument's type is matched against the return
6013 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6014
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6015<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6016 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6017
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6018<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6019<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6020 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6021</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6022
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6023<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6024
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6025<p>Variable argument support is defined in LLVM with
6026 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
6027 intrinsic functions. These functions are related to the similarly named
6028 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6029
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6030<p>All of these functions operate on arguments that use a target-specific value
6031 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
6032 not define what this type is, so all transformations should be prepared to
6033 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6034
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]6035<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]6036 instruction and the variable argument handling intrinsic functions are
6037 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6038
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]6039<pre class="doc_code">
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6040define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6041 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6042 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6043 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6044 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6045
6046 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6047 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6048
6049 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6050 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6051 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6052 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6053 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6054
6055 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6056 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]6057 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6058}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6059
6060declare void @llvm.va_start(i8*)
6061declare void @llvm.va_copy(i8*, i8*)
6062declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6063</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6064
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6065<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6066<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6067 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6068</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6069
6070
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6071<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6072
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6073<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6074<pre>
6075 declare void %llvm.va_start(i8* &lt;arglist&gt;)
6076</pre>
6077
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6078<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6079<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
6080 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]6081
6082<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6083<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]6084
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6085<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6086<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]6087 macro available in C. In a target-dependent way, it initializes
6088 the <tt>va_list</tt> element to which the argument points, so that the next
6089 call to <tt>va_arg</tt> will produce the first variable argument passed to
6090 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
6091 need to know the last argument of the function as the compiler can figure
6092 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6093
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6094</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6095
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6096<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6097<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6098 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6099</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6100
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6101<div>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6102
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6103<h5>Syntax:</h5>
6104<pre>
6105 declare void @llvm.va_end(i8* &lt;arglist&gt;)
6106</pre>
6107
6108<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6109<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6110 which has been initialized previously
6111 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
6112 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6113
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6114<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6115<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]6116
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6117<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6118<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]6119 macro available in C. In a target-dependent way, it destroys
6120 the <tt>va_list</tt> element to which the argument points. Calls
6121 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
6122 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
6123 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6124
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6125</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6126
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6127<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6128<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6129 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6130</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6131
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6132<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6133
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6134<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6135<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6136 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6137</pre>
6138
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6139<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6140<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6141 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6142
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6143<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6144<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]6145 The second argument is a pointer to a <tt>va_list</tt> element to copy
6146 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6147
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6148<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6149<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]6150 macro available in C. In a target-dependent way, it copies the
6151 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
6152 element. This intrinsic is necessary because
6153 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
6154 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6155
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6156</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6157
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6158</div>
6159
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6160<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6161<h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6162 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6163</h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6164
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6165<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6166
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6167<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]6168Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6169intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
6170roots on the stack</a>, as well as garbage collector implementations that
6171require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
6172barriers. Front-ends for type-safe garbage collected languages should generate
6173these intrinsics to make use of the LLVM garbage collectors. For more details,
6174see <a href="GarbageCollection.html">Accurate Garbage Collection with
6175LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]6176
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6177<p>The garbage collection intrinsics only operate on objects in the generic
6178 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]6179
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6180<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6181<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6182 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6183</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6184
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6185<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6186
6187<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6188<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6189 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6190</pre>
6191
6192<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]6193<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]6194 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6195
6196<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6197<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6198 root pointer. The second pointer (which must be either a constant or a
6199 global value address) contains the meta-data to be associated with the
6200 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6201
6202<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]6203<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]6204 location. At compile-time, the code generator generates information to allow
6205 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
6206 intrinsic may only be used in a function which <a href="#gc">specifies a GC
6207 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6208
6209</div>
6210
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6211<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6212<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6213 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6214</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6215
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6216<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6217
6218<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6219<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6220 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6221</pre>
6222
6223<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6224<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6225 locations, allowing garbage collector implementations that require read
6226 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6227
6228<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]6229<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]6230 allocated from the garbage collector. The first object is a pointer to the
6231 start of the referenced object, if needed by the language runtime (otherwise
6232 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6233
6234<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6235<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6236 instruction, but may be replaced with substantially more complex code by the
6237 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
6238 may only be used in a function which <a href="#gc">specifies a GC
6239 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6240
6241</div>
6242
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6243<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6244<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6245 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6246</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6247
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6248<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6249
6250<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6251<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6252 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6253</pre>
6254
6255<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6256<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6257 locations, allowing garbage collector implementations that require write
6258 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6259
6260<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]6261<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]6262 object to store it to, and the third is the address of the field of Obj to
6263 store to. If the runtime does not require a pointer to the object, Obj may
6264 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6265
6266<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6267<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6268 instruction, but may be replaced with substantially more complex code by the
6269 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
6270 may only be used in a function which <a href="#gc">specifies a GC
6271 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6272
6273</div>
6274
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6275</div>
6276
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6277<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6278<h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6279 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6280</h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6281
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6282<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6283
6284<p>These intrinsics are provided by LLVM to expose special features that may
6285 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6286
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6287<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6288<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6289 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6290</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6291
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6292<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6293
6294<h5>Syntax:</h5>
6295<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6296 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6297</pre>
6298
6299<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6300<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
6301 target-specific value indicating the return address of the current function
6302 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6303
6304<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6305<p>The argument to this intrinsic indicates which function to return the address
6306 for. Zero indicates the calling function, one indicates its caller, etc.
6307 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6308
6309<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6310<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
6311 indicating the return address of the specified call frame, or zero if it
6312 cannot be identified. The value returned by this intrinsic is likely to be
6313 incorrect or 0 for arguments other than zero, so it should only be used for
6314 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6315
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6316<p>Note that calling this intrinsic does not prevent function inlining or other
6317 aggressive transformations, so the value returned may not be that of the
6318 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6319
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6320</div>
6321
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6322<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6323<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6324 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6325</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6326
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6327<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6328
6329<h5>Syntax:</h5>
6330<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6331 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6332</pre>
6333
6334<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6335<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6336 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6337
6338<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6339<p>The argument to this intrinsic indicates which function to return the frame
6340 pointer for. Zero indicates the calling function, one indicates its caller,
6341 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6342
6343<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6344<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6345 indicating the frame address of the specified call frame, or zero if it
6346 cannot be identified. The value returned by this intrinsic is likely to be
6347 incorrect or 0 for arguments other than zero, so it should only be used for
6348 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6349
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6350<p>Note that calling this intrinsic does not prevent function inlining or other
6351 aggressive transformations, so the value returned may not be that of the
6352 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6353
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6354</div>
6355
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6356<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6357<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6358 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6359</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6360
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6361<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6362
6363<h5>Syntax:</h5>
6364<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6365 declare i8* @llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6366</pre>
6367
6368<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6369<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6370 of the function stack, for use
6371 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6372 useful for implementing language features like scoped automatic variable
6373 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6374
6375<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6376<p>This intrinsic returns a opaque pointer value that can be passed
6377 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6378 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6379 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6380 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6381 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6382 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6383
6384</div>
6385
6386<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6387<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6388 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6389</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6390
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6391<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6392
6393<h5>Syntax:</h5>
6394<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6395 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6396</pre>
6397
6398<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6399<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6400 the function stack to the state it was in when the
6401 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6402 executed. This is useful for implementing language features like scoped
6403 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6404
6405<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6406<p>See the description
6407 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6408
6409</div>
6410
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6411<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6412<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6413 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6414</h4>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6415
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6416<div>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6417
6418<h5>Syntax:</h5>
6419<pre>
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6420 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]6421</pre>
6422
6423<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6424<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6425 insert a prefetch instruction if supported; otherwise, it is a noop.
6426 Prefetches have no effect on the behavior of the program but can change its
6427 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6428
6429<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6430<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6431 specifier determining if the fetch should be for a read (0) or write (1),
6432 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6433 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6434 specifies whether the prefetch is performed on the data (1) or instruction (0)
6435 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6436 must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6437
6438<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6439<p>This intrinsic does not modify the behavior of the program. In particular,
6440 prefetches cannot trap and do not produce a value. On targets that support
6441 this intrinsic, the prefetch can provide hints to the processor cache for
6442 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6443
6444</div>
6445
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6446<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6447<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6448 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6449</h4>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6450
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6451<div>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6452
6453<h5>Syntax:</h5>
6454<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6455 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6456</pre>
6457
6458<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6459<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6460 Counter (PC) in a region of code to simulators and other tools. The method
6461 is target specific, but it is expected that the marker will use exported
6462 symbols to transmit the PC of the marker. The marker makes no guarantees
6463 that it will remain with any specific instruction after optimizations. It is
6464 possible that the presence of a marker will inhibit optimizations. The
6465 intended use is to be inserted after optimizations to allow correlations of
6466 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6467
6468<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6469<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6470
6471<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6472<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6473 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6474
6475</div>
6476
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6477<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6478<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6479 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6480</h4>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6481
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6482<div>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6483
6484<h5>Syntax:</h5>
6485<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]6486 declare i64 @llvm.readcyclecounter()
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6487</pre>
6488
6489<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6490<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6491 counter register (or similar low latency, high accuracy clocks) on those
6492 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6493 should map to RPCC. As the backing counters overflow quickly (on the order
6494 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6495
6496<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6497<p>When directly supported, reading the cycle counter should not modify any
6498 memory. Implementations are allowed to either return a application specific
6499 value or a system wide value. On backends without support, this is lowered
6500 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6501
6502</div>
6503
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6504</div>
6505
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6506<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6507<h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6508 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6509</h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6510
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6511<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6512
6513<p>LLVM provides intrinsics for a few important standard C library functions.
6514 These intrinsics allow source-language front-ends to pass information about
6515 the alignment of the pointer arguments to the code generator, providing
6516 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6517
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6518<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6519<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6520 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6521</h4>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6522
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6523<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6524
6525<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6526<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]6527 integer bit width and for different address spaces. Not all targets support
6528 all bit widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6529
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6530<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6531 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]6532 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6533 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]6534 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6535</pre>
6536
6537<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6538<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6539 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6540
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6541<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6542 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6543 and the pointers can be in specified address spaces.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6544
6545<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6546
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6547<p>The first argument is a pointer to the destination, the second is a pointer
6548 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6549 number of bytes to copy, the fourth argument is the alignment of the
6550 source and destination locations, and the fifth is a boolean indicating a
6551 volatile access.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6552
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6553<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]6554 then the caller guarantees that both the source and destination pointers are
6555 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6556
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6557<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6558 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6559 The detailed access behavior is not very cleanly specified and it is unwise
6560 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6561
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6562<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6563
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6564<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6565 source location to the destination location, which are not allowed to
6566 overlap. It copies "len" bytes of memory over. If the argument is known to
6567 be aligned to some boundary, this can be specified as the fourth argument,
6568 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6569
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6570</div>
6571
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6572<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6573<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6574 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6575</h4>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6576
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6577<div>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6578
6579<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6580<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]6581 width and for different address space. Not all targets support all bit
6582 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6583
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6584<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6585 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]6586 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6587 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]6588 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6589</pre>
6590
6591<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6592<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6593 source location to the destination location. It is similar to the
6594 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6595 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6596
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6597<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6598 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6599 and the pointers can be in specified address spaces.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6600
6601<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6602
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6603<p>The first argument is a pointer to the destination, the second is a pointer
6604 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6605 number of bytes to copy, the fourth argument is the alignment of the
6606 source and destination locations, and the fifth is a boolean indicating a
6607 volatile access.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6608
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6609<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]6610 then the caller guarantees that the source and destination pointers are
6611 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6612
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6613<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6614 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6615 The detailed access behavior is not very cleanly specified and it is unwise
6616 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6617
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6618<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6619
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6620<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6621 source location to the destination location, which may overlap. It copies
6622 "len" bytes of memory over. If the argument is known to be aligned to some
6623 boundary, this can be specified as the fourth argument, otherwise it should
6624 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6625
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6626</div>
6627
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6628<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6629<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6630 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6631</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6632
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6633<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6634
6635<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6636<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]6637 width and for different address spaces. However, not all targets support all
6638 bit widths.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6639
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6640<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6641 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6642 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6643 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6644 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6645</pre>
6646
6647<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6648<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6649 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6650
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6651<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6652 intrinsic does not return a value and takes extra alignment/volatile
6653 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6654
6655<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6656<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]6657 byte value with which to fill it, the third argument is an integer argument
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6658 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6659 alignment of the destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6660
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6661<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]6662 then the caller guarantees that the destination pointer is aligned to that
6663 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6664
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6665<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6666 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6667 The detailed access behavior is not very cleanly specified and it is unwise
6668 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6669
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6670<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6671<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6672 at the destination location. If the argument is known to be aligned to some
6673 boundary, this can be specified as the fourth argument, otherwise it should
6674 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6675
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6676</div>
6677
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6678<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6679<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6680 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6681</h4>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6682
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6683<div>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6684
6685<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6686<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6687 floating point or vector of floating point type. Not all targets support all
6688 types however.</p>
6689
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6690<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6691 declare float @llvm.sqrt.f32(float %Val)
6692 declare double @llvm.sqrt.f64(double %Val)
6693 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6694 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6695 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6696</pre>
6697
6698<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6699<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6700 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6701 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6702 behavior for negative numbers other than -0.0 (which allows for better
6703 optimization, because there is no need to worry about errno being
6704 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]6705
6706<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6707<p>The argument and return value are floating point numbers of the same
6708 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6709
6710<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6711<p>This function returns the sqrt of the specified operand if it is a
6712 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6713
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6714</div>
6715
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6716<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6717<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6718 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6719</h4>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6720
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6721<div>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6722
6723<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6724<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6725 floating point or vector of floating point type. Not all targets support all
6726 types however.</p>
6727
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6728<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6729 declare float @llvm.powi.f32(float %Val, i32 %power)
6730 declare double @llvm.powi.f64(double %Val, i32 %power)
6731 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6732 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6733 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6734</pre>
6735
6736<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6737<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6738 specified (positive or negative) power. The order of evaluation of
6739 multiplications is not defined. When a vector of floating point type is
6740 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6741
6742<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6743<p>The second argument is an integer power, and the first is a value to raise to
6744 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6745
6746<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6747<p>This function returns the first value raised to the second power with an
6748 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6749
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6750</div>
6751
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6752<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6753<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6754 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6755</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6756
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6757<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6758
6759<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6760<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6761 floating point or vector of floating point type. Not all targets support all
6762 types however.</p>
6763
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6764<pre>
6765 declare float @llvm.sin.f32(float %Val)
6766 declare double @llvm.sin.f64(double %Val)
6767 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6768 declare fp128 @llvm.sin.f128(fp128 %Val)
6769 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6770</pre>
6771
6772<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6773<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6774
6775<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6776<p>The argument and return value are floating point numbers of the same
6777 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6778
6779<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6780<p>This function returns the sine of the specified operand, returning the same
6781 values as the libm <tt>sin</tt> functions would, and handles error conditions
6782 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6783
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6784</div>
6785
6786<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6787<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6788 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6789</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6790
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6791<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6792
6793<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6794<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6795 floating point or vector of floating point type. Not all targets support all
6796 types however.</p>
6797
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6798<pre>
6799 declare float @llvm.cos.f32(float %Val)
6800 declare double @llvm.cos.f64(double %Val)
6801 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6802 declare fp128 @llvm.cos.f128(fp128 %Val)
6803 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6804</pre>
6805
6806<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6807<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6808
6809<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6810<p>The argument and return value are floating point numbers of the same
6811 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6812
6813<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6814<p>This function returns the cosine of the specified operand, returning the same
6815 values as the libm <tt>cos</tt> functions would, and handles error conditions
6816 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6817
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6818</div>
6819
6820<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6821<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6822 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6823</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6824
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6825<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6826
6827<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6828<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6829 floating point or vector of floating point type. Not all targets support all
6830 types however.</p>
6831
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6832<pre>
6833 declare float @llvm.pow.f32(float %Val, float %Power)
6834 declare double @llvm.pow.f64(double %Val, double %Power)
6835 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6836 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6837 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6838</pre>
6839
6840<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6841<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6842 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6843
6844<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6845<p>The second argument is a floating point power, and the first is a value to
6846 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6847
6848<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6849<p>This function returns the first value raised to the second power, returning
6850 the same values as the libm <tt>pow</tt> functions would, and handles error
6851 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6852
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6853</div>
6854
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6855</div>
6856
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]6857<!-- _______________________________________________________________________ -->
6858<h4>
6859 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6860</h4>
6861
6862<div>
6863
6864<h5>Syntax:</h5>
6865<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6866 floating point or vector of floating point type. Not all targets support all
6867 types however.</p>
6868
6869<pre>
6870 declare float @llvm.exp.f32(float %Val)
6871 declare double @llvm.exp.f64(double %Val)
6872 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6873 declare fp128 @llvm.exp.f128(fp128 %Val)
6874 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6875</pre>
6876
6877<h5>Overview:</h5>
6878<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6879
6880<h5>Arguments:</h5>
6881<p>The argument and return value are floating point numbers of the same
6882 type.</p>
6883
6884<h5>Semantics:</h5>
6885<p>This function returns the same values as the libm <tt>exp</tt> functions
6886 would, and handles error conditions in the same way.</p>
6887
6888</div>
6889
6890<!-- _______________________________________________________________________ -->
6891<h4>
6892 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6893</h4>
6894
6895<div>
6896
6897<h5>Syntax:</h5>
6898<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6899 floating point or vector of floating point type. Not all targets support all
6900 types however.</p>
6901
6902<pre>
6903 declare float @llvm.log.f32(float %Val)
6904 declare double @llvm.log.f64(double %Val)
6905 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6906 declare fp128 @llvm.log.f128(fp128 %Val)
6907 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6908</pre>
6909
6910<h5>Overview:</h5>
6911<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6912
6913<h5>Arguments:</h5>
6914<p>The argument and return value are floating point numbers of the same
6915 type.</p>
6916
6917<h5>Semantics:</h5>
6918<p>This function returns the same values as the libm <tt>log</tt> functions
6919 would, and handles error conditions in the same way.</p>
6920
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]6921<h4>
6922 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
6923</h4>
6924
6925<div>
6926
6927<h5>Syntax:</h5>
6928<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
6929 floating point or vector of floating point type. Not all targets support all
6930 types however.</p>
6931
6932<pre>
6933 declare float @llvm.fma.f32(float %a, float %b, float %c)
6934 declare double @llvm.fma.f64(double %a, double %b, double %c)
6935 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
6936 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
6937 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
6938</pre>
6939
6940<h5>Overview:</h5>
Cameron Zwarichabc43e62011-07-08 22:13:55 +0000[diff] [blame]6941<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]6942 operation.</p>
6943
6944<h5>Arguments:</h5>
6945<p>The argument and return value are floating point numbers of the same
6946 type.</p>
6947
6948<h5>Semantics:</h5>
6949<p>This function returns the same values as the libm <tt>fma</tt> functions
6950 would.</p>
6951
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]6952</div>
6953
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6954<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6955<h3>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6956 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6957</h3>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6958
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6959<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6960
6961<p>LLVM provides intrinsics for a few important bit manipulation operations.
6962 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6963
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6964<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6965<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6966 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6967</h4>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6968
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6969<div>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6970
6971<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6972<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6973 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6974
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6975<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6976 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6977 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6978 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6979</pre>
6980
6981<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6982<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6983 values with an even number of bytes (positive multiple of 16 bits). These
6984 are useful for performing operations on data that is not in the target's
6985 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6986
6987<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6988<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6989 and low byte of the input i16 swapped. Similarly,
6990 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6991 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6992 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6993 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6994 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6995 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6996
6997</div>
6998
6999<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7000<h4>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]7001 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7002</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7003
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7004<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7005
7006<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]7007<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]7008 width, or on any vector with integer elements. Not all targets support all
7009 bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7010
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7011<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7012 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7013 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7014 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7015 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
7016 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7017 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]7018</pre>
7019
7020<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7021<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
7022 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7023
7024<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7025<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]7026 integer type, or a vector with integer elements.
7027 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7028
7029<h5>Semantics:</h5>
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7030<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
7031 element of a vector.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7032
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7033</div>
7034
7035<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7036<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]7037 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7038</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7039
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7040<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7041
7042<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7043<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]7044 integer bit width, or any vector whose elements are integers. Not all
7045 targets support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7046
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7047<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7048 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
7049 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7050 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7051 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
7052 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7053 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]7054</pre>
7055
7056<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7057<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
7058 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7059
7060<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7061<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]7062 integer type, or any vector type with integer element type.
7063 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7064
7065<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7066<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7067 zeros in a variable, or within each element of the vector if the operation
7068 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]7069 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7070
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7071</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]7072
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7073<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7074<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]7075 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7076</h4>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7077
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7078<div>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7079
7080<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7081<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]7082 integer bit width, or any vector of integer elements. Not all targets
7083 support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7084
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7085<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7086 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
7087 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7088 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7089 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
7090 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7091 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]7092</pre>
7093
7094<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7095<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
7096 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7097
7098<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7099<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]7100 integer type, or a vectory with integer element type.. The return type
7101 must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7102
7103<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7104<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7105 zeros in a variable, or within each element of a vector.
7106 If the src == 0 then the result is the size in bits of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7107 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7108
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7109</div>
7110
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7111</div>
7112
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7113<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7114<h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7115 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7116</h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7117
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7118<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7119
7120<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7121
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7122<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7123<h4>
7124 <a name="int_sadd_overflow">
7125 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
7126 </a>
7127</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7128
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7129<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7130
7131<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7132<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]7133 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7134
7135<pre>
7136 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
7137 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7138 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
7139</pre>
7140
7141<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7142<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7143 a signed addition of the two arguments, and indicate whether an overflow
7144 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7145
7146<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7147<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]7148 be of integer types of any bit width, but they must have the same bit
7149 width. The second element of the result structure must be of
7150 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7151 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7152
7153<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7154<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7155 a signed addition of the two variables. They return a structure &mdash; the
7156 first element of which is the signed summation, and the second element of
7157 which is a bit specifying if the signed summation resulted in an
7158 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7159
7160<h5>Examples:</h5>
7161<pre>
7162 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7163 %sum = extractvalue {i32, i1} %res, 0
7164 %obit = extractvalue {i32, i1} %res, 1
7165 br i1 %obit, label %overflow, label %normal
7166</pre>
7167
7168</div>
7169
7170<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7171<h4>
7172 <a name="int_uadd_overflow">
7173 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
7174 </a>
7175</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7176
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7177<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7178
7179<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7180<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]7181 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7182
7183<pre>
7184 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
7185 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7186 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
7187</pre>
7188
7189<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7190<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7191 an unsigned addition of the two arguments, and indicate whether a carry
7192 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7193
7194<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7195<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]7196 be of integer types of any bit width, but they must have the same bit
7197 width. The second element of the result structure must be of
7198 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7199 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7200
7201<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7202<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7203 an unsigned addition of the two arguments. They return a structure &mdash;
7204 the first element of which is the sum, and the second element of which is a
7205 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7206
7207<h5>Examples:</h5>
7208<pre>
7209 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7210 %sum = extractvalue {i32, i1} %res, 0
7211 %obit = extractvalue {i32, i1} %res, 1
7212 br i1 %obit, label %carry, label %normal
7213</pre>
7214
7215</div>
7216
7217<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7218<h4>
7219 <a name="int_ssub_overflow">
7220 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
7221 </a>
7222</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7223
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7224<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7225
7226<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7227<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]7228 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7229
7230<pre>
7231 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
7232 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7233 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
7234</pre>
7235
7236<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7237<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7238 a signed subtraction of the two arguments, and indicate whether an overflow
7239 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7240
7241<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7242<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]7243 be of integer types of any bit width, but they must have the same bit
7244 width. The second element of the result structure must be of
7245 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7246 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7247
7248<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7249<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7250 a signed subtraction of the two arguments. They return a structure &mdash;
7251 the first element of which is the subtraction, and the second element of
7252 which is a bit specifying if the signed subtraction resulted in an
7253 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7254
7255<h5>Examples:</h5>
7256<pre>
7257 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7258 %sum = extractvalue {i32, i1} %res, 0
7259 %obit = extractvalue {i32, i1} %res, 1
7260 br i1 %obit, label %overflow, label %normal
7261</pre>
7262
7263</div>
7264
7265<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7266<h4>
7267 <a name="int_usub_overflow">
7268 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
7269 </a>
7270</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7271
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7272<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7273
7274<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7275<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7276 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7277
7278<pre>
7279 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
7280 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7281 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
7282</pre>
7283
7284<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7285<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7286 an unsigned subtraction of the two arguments, and indicate whether an
7287 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7288
7289<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7290<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7291 be of integer types of any bit width, but they must have the same bit
7292 width. The second element of the result structure must be of
7293 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7294 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7295
7296<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7297<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7298 an unsigned subtraction of the two arguments. They return a structure &mdash;
7299 the first element of which is the subtraction, and the second element of
7300 which is a bit specifying if the unsigned subtraction resulted in an
7301 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7302
7303<h5>Examples:</h5>
7304<pre>
7305 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7306 %sum = extractvalue {i32, i1} %res, 0
7307 %obit = extractvalue {i32, i1} %res, 1
7308 br i1 %obit, label %overflow, label %normal
7309</pre>
7310
7311</div>
7312
7313<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7314<h4>
7315 <a name="int_smul_overflow">
7316 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
7317 </a>
7318</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7319
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7320<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7321
7322<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7323<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7324 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7325
7326<pre>
7327 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
7328 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7329 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
7330</pre>
7331
7332<h5>Overview:</h5>
7333
7334<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7335 a signed multiplication of the two arguments, and indicate whether an
7336 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7337
7338<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7339<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]7340 be of integer types of any bit width, but they must have the same bit
7341 width. The second element of the result structure must be of
7342 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7343 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7344
7345<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7346<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7347 a signed multiplication of the two arguments. They return a structure &mdash;
7348 the first element of which is the multiplication, and the second element of
7349 which is a bit specifying if the signed multiplication resulted in an
7350 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7351
7352<h5>Examples:</h5>
7353<pre>
7354 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7355 %sum = extractvalue {i32, i1} %res, 0
7356 %obit = extractvalue {i32, i1} %res, 1
7357 br i1 %obit, label %overflow, label %normal
7358</pre>
7359
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]7360</div>
7361
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7362<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7363<h4>
7364 <a name="int_umul_overflow">
7365 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7366 </a>
7367</h4>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7368
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7369<div>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7370
7371<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7372<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]7373 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7374
7375<pre>
7376 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7377 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7378 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7379</pre>
7380
7381<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7382<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7383 a unsigned multiplication of the two arguments, and indicate whether an
7384 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7385
7386<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7387<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]7388 be of integer types of any bit width, but they must have the same bit
7389 width. The second element of the result structure must be of
7390 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7391 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7392
7393<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7394<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7395 an unsigned multiplication of the two arguments. They return a structure
7396 &mdash; the first element of which is the multiplication, and the second
7397 element of which is a bit specifying if the unsigned multiplication resulted
7398 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7399
7400<h5>Examples:</h5>
7401<pre>
7402 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7403 %sum = extractvalue {i32, i1} %res, 0
7404 %obit = extractvalue {i32, i1} %res, 1
7405 br i1 %obit, label %overflow, label %normal
7406</pre>
7407
7408</div>
7409
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7410</div>
7411
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7412<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7413<h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7414 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7415</h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7416
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7417<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7418
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7419<p>Half precision floating point is a storage-only format. This means that it is
7420 a dense encoding (in memory) but does not support computation in the
7421 format.</p>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7422
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7423<p>This means that code must first load the half-precision floating point
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7424 value as an i16, then convert it to float with <a
7425 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7426 Computation can then be performed on the float value (including extending to
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7427 double etc). To store the value back to memory, it is first converted to
7428 float if needed, then converted to i16 with
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7429 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7430 storing as an i16 value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7431
7432<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7433<h4>
7434 <a name="int_convert_to_fp16">
7435 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7436 </a>
7437</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7438
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7439<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7440
7441<h5>Syntax:</h5>
7442<pre>
7443 declare i16 @llvm.convert.to.fp16(f32 %a)
7444</pre>
7445
7446<h5>Overview:</h5>
7447<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7448 a conversion from single precision floating point format to half precision
7449 floating point format.</p>
7450
7451<h5>Arguments:</h5>
7452<p>The intrinsic function contains single argument - the value to be
7453 converted.</p>
7454
7455<h5>Semantics:</h5>
7456<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7457 a conversion from single precision floating point format to half precision
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7458 floating point format. The return value is an <tt>i16</tt> which
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7459 contains the converted number.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7460
7461<h5>Examples:</h5>
7462<pre>
7463 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7464 store i16 %res, i16* @x, align 2
7465</pre>
7466
7467</div>
7468
7469<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7470<h4>
7471 <a name="int_convert_from_fp16">
7472 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7473 </a>
7474</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7475
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7476<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7477
7478<h5>Syntax:</h5>
7479<pre>
7480 declare f32 @llvm.convert.from.fp16(i16 %a)
7481</pre>
7482
7483<h5>Overview:</h5>
7484<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7485 a conversion from half precision floating point format to single precision
7486 floating point format.</p>
7487
7488<h5>Arguments:</h5>
7489<p>The intrinsic function contains single argument - the value to be
7490 converted.</p>
7491
7492<h5>Semantics:</h5>
7493<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7494 conversion from half single precision floating point format to single
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7495 precision floating point format. The input half-float value is represented by
7496 an <tt>i16</tt> value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7497
7498<h5>Examples:</h5>
7499<pre>
7500 %a = load i16* @x, align 2
7501 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7502</pre>
7503
7504</div>
7505
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7506</div>
7507
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7508<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7509<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7510 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7511</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7512
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7513<div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7514
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7515<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7516 prefix), are described in
7517 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7518 Level Debugging</a> document.</p>
7519
7520</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7521
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7522<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7523<h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7524 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7525</h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7526
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7527<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7528
7529<p>The LLVM exception handling intrinsics (which all start with
7530 <tt>llvm.eh.</tt> prefix), are described in
7531 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7532 Handling</a> document.</p>
7533
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7534</div>
7535
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7536<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7537<h3>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7538 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7539</h3>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7540
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7541<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7542
7543<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]7544 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7545 The result is a callable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7546 function pointer lacking the nest parameter - the caller does not need to
7547 provide a value for it. Instead, the value to use is stored in advance in a
7548 "trampoline", a block of memory usually allocated on the stack, which also
7549 contains code to splice the nest value into the argument list. This is used
7550 to implement the GCC nested function address extension.</p>
7551
7552<p>For example, if the function is
7553 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7554 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7555 follows:</p>
7556
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]7557<pre class="doc_code">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7558 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7559 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7560 %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]7561 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7562</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7563
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7564<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7565 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7566
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7567<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7568<h4>
7569 <a name="int_it">
7570 '<tt>llvm.init.trampoline</tt>' Intrinsic
7571 </a>
7572</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7573
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7574<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7575
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7576<h5>Syntax:</h5>
7577<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7578 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]7579</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7580
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7581<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7582<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7583 function pointer suitable for executing it.</p>
7584
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7585<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7586<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7587 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7588 sufficiently aligned block of memory; this memory is written to by the
7589 intrinsic. Note that the size and the alignment are target-specific - LLVM
7590 currently provides no portable way of determining them, so a front-end that
7591 generates this intrinsic needs to have some target-specific knowledge.
7592 The <tt>func</tt> argument must hold a function bitcast to
7593 an <tt>i8*</tt>.</p>
7594
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7595<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7596<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7597 dependent code, turning it into a function. A pointer to this function is
7598 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7599 function pointer type</a> before being called. The new function's signature
7600 is the same as that of <tt>func</tt> with any arguments marked with
7601 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7602 is allowed, and it must be of pointer type. Calling the new function is
7603 equivalent to calling <tt>func</tt> with the same argument list, but
7604 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7605 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7606 by <tt>tramp</tt> is modified, then the effect of any later call to the
7607 returned function pointer is undefined.</p>
7608
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7609</div>
7610
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7611</div>
7612
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7613<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7614<h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7615 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7616</h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7617
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7618<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7619
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7620<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7621 hardware constructs for atomic operations and memory synchronization. This
7622 provides an interface to the hardware, not an interface to the programmer. It
7623 is aimed at a low enough level to allow any programming models or APIs
7624 (Application Programming Interfaces) which need atomic behaviors to map
7625 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7626 hardware provides a "universal IR" for source languages, it also provides a
7627 starting point for developing a "universal" atomic operation and
7628 synchronization IR.</p>
7629
7630<p>These do <em>not</em> form an API such as high-level threading libraries,
7631 software transaction memory systems, atomic primitives, and intrinsic
7632 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7633 application libraries. The hardware interface provided by LLVM should allow
7634 a clean implementation of all of these APIs and parallel programming models.
7635 No one model or paradigm should be selected above others unless the hardware
7636 itself ubiquitously does so.</p>
7637
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7638<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7639<h4>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7640 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7641</h4>
7642
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7643<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7644<h5>Syntax:</h5>
7645<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7646 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]7647</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7648
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7649<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7650<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7651 specific pairs of memory access types.</p>
7652
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7653<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7654<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7655 The first four arguments enables a specific barrier as listed below. The
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]7656 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7657 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7658
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7659<ul>
7660 <li><tt>ll</tt>: load-load barrier</li>
7661 <li><tt>ls</tt>: load-store barrier</li>
7662 <li><tt>sl</tt>: store-load barrier</li>
7663 <li><tt>ss</tt>: store-store barrier</li>
7664 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7665</ul>
7666
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7667<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7668<p>This intrinsic causes the system to enforce some ordering constraints upon
7669 the loads and stores of the program. This barrier does not
7670 indicate <em>when</em> any events will occur, it only enforces
7671 an <em>order</em> in which they occur. For any of the specified pairs of load
7672 and store operations (f.ex. load-load, or store-load), all of the first
7673 operations preceding the barrier will complete before any of the second
7674 operations succeeding the barrier begin. Specifically the semantics for each
7675 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7676
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7677<ul>
7678 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7679 after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7680 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7681 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7682 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7683 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7684 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7685 load after the barrier begins.</li>
7686</ul>
7687
7688<p>These semantics are applied with a logical "and" behavior when more than one
7689 is enabled in a single memory barrier intrinsic.</p>
7690
7691<p>Backends may implement stronger barriers than those requested when they do
7692 not support as fine grained a barrier as requested. Some architectures do
7693 not need all types of barriers and on such architectures, these become
7694 noops.</p>
7695
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7696<h5>Example:</h5>
7697<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7698%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7699%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7700 store i32 4, %ptr
7701
7702%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0b0669a2011-06-29 17:14:00 +0000[diff] [blame]7703 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]7704 <i>; guarantee the above finishes</i>
7705 store i32 8, %ptr <i>; before this begins</i>
7706</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7707
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7708</div>
7709
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7710<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7711<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7712 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7713</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7714
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7715<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7716
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7717<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7718<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7719 any integer bit width and for different address spaces. Not all targets
7720 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7721
7722<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7723 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7724 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7725 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7726 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]7727</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7728
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7729<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7730<p>This loads a value in memory and compares it to a given value. If they are
7731 equal, it stores a new value into the memory.</p>
7732
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7733<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7734<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7735 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7736 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7737 this integer type. While any bit width integer may be used, targets may only
7738 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7739
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7740<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7741<p>This entire intrinsic must be executed atomically. It first loads the value
7742 in memory pointed to by <tt>ptr</tt> and compares it with the
7743 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7744 memory. The loaded value is yielded in all cases. This provides the
7745 equivalent of an atomic compare-and-swap operation within the SSA
7746 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7747
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7748<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7749<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7750%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7751%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7752 store i32 4, %ptr
7753
7754%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7755%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7756 <i>; yields {i32}:result1 = 4</i>
7757%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7758%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7759
7760%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7761%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7762 <i>; yields {i32}:result2 = 8</i>
7763%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7764
7765%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7766</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7767
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7768</div>
7769
7770<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7771<h4>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7772 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7773</h4>
7774
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7775<div>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7776<h5>Syntax:</h5>
7777
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7778<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7779 integer bit width. Not all targets support all bit widths however.</p>
7780
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7781<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7782 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7783 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7784 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7785 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]7786</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7787
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7788<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7789<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7790 the value from memory. It then stores the value in <tt>val</tt> in the memory
7791 at <tt>ptr</tt>.</p>
7792
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7793<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7794<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7795 the <tt>val</tt> argument and the result must be integers of the same bit
7796 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7797 integer type. The targets may only lower integer representations they
7798 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7799
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7800<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7801<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7802 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7803 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7804
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7805<h5>Examples:</h5>
7806<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7807%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7808%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7809 store i32 4, %ptr
7810
7811%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7812%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7813 <i>; yields {i32}:result1 = 4</i>
7814%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7815%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7816
7817%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7818%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7819 <i>; yields {i32}:result2 = 8</i>
7820
7821%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7822%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7823</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7824
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7825</div>
7826
7827<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7828<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7829 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7830</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7831
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7832<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7833
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7834<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7835<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7836 any integer bit width. Not all targets support all bit widths however.</p>
7837
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7838<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7839 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7840 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7841 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7842 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]7843</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7844
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7845<h5>Overview:</h5>
7846<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7847 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7848
7849<h5>Arguments:</h5>
7850<p>The intrinsic takes two arguments, the first a pointer to an integer value
7851 and the second an integer value. The result is also an integer value. These
7852 integer types can have any bit width, but they must all have the same bit
7853 width. The targets may only lower integer representations they support.</p>
7854
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7855<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7856<p>This intrinsic does a series of operations atomically. It first loads the
7857 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7858 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]7859
7860<h5>Examples:</h5>
7861<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7862%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7863%ptr = bitcast i8* %mallocP to i32*
7864 store i32 4, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7865%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7866 <i>; yields {i32}:result1 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7867%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7868 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7869%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7870 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7871%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7872</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7873
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7874</div>
7875
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7876<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7877<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7878 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7879</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7880
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7881<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7882
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7883<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7884<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7885 any integer bit width and for different address spaces. Not all targets
7886 support all bit widths however.</p>
7887
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7888<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7889 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7890 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7891 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7892 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]7893</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7894
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7895<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7896<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7897 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7898
7899<h5>Arguments:</h5>
7900<p>The intrinsic takes two arguments, the first a pointer to an integer value
7901 and the second an integer value. The result is also an integer value. These
7902 integer types can have any bit width, but they must all have the same bit
7903 width. The targets may only lower integer representations they support.</p>
7904
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7905<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7906<p>This intrinsic does a series of operations atomically. It first loads the
7907 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7908 result to <tt>ptr</tt>. It yields the original value stored
7909 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7910
7911<h5>Examples:</h5>
7912<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7913%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7914%ptr = bitcast i8* %mallocP to i32*
7915 store i32 8, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7916%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7917 <i>; yields {i32}:result1 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7918%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7919 <i>; yields {i32}:result2 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7920%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7921 <i>; yields {i32}:result3 = 2</i>
7922%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7923</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7924
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7925</div>
7926
7927<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7928<h4>
7929 <a name="int_atomic_load_and">
7930 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7931 </a>
7932 <br>
7933 <a name="int_atomic_load_nand">
7934 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7935 </a>
7936 <br>
7937 <a name="int_atomic_load_or">
7938 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7939 </a>
7940 <br>
7941 <a name="int_atomic_load_xor">
7942 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7943 </a>
7944</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7945
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7946<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7947
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7948<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7949<p>These are overloaded intrinsics. You can
7950 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7951 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7952 bit width and for different address spaces. Not all targets support all bit
7953 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7954
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7955<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7956 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7957 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7958 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7959 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]7960</pre>
7961
7962<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7963 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7964 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7965 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7966 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]7967</pre>
7968
7969<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7970 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7971 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7972 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7973 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]7974</pre>
7975
7976<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7977 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7978 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7979 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7980 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]7981</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7982
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7983<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7984<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7985 the value stored in memory at <tt>ptr</tt>. It yields the original value
7986 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7987
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7988<h5>Arguments:</h5>
7989<p>These intrinsics take two arguments, the first a pointer to an integer value
7990 and the second an integer value. The result is also an integer value. These
7991 integer types can have any bit width, but they must all have the same bit
7992 width. The targets may only lower integer representations they support.</p>
7993
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7994<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7995<p>These intrinsics does a series of operations atomically. They first load the
7996 value stored at <tt>ptr</tt>. They then do the bitwise
7997 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7998 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7999
8000<h5>Examples:</h5>
8001<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]8002%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8003%ptr = bitcast i8* %mallocP to i32*
8004 store i32 0x0F0F, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8005%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8006 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8007%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8008 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8009%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8010 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8011%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8012 <i>; yields {i32}:result3 = FF</i>
8013%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
8014</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8015
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8016</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8017
8018<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8019<h4>
8020 <a name="int_atomic_load_max">
8021 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
8022 </a>
8023 <br>
8024 <a name="int_atomic_load_min">
8025 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
8026 </a>
8027 <br>
8028 <a name="int_atomic_load_umax">
8029 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
8030 </a>
8031 <br>
8032 <a name="int_atomic_load_umin">
8033 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
8034 </a>
8035</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8036
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8037<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8038
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8039<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8040<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
8041 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
8042 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
8043 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8044
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8045<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8046 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8047 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8048 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8049 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]8050</pre>
8051
8052<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8053 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8054 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8055 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8056 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]8057</pre>
8058
8059<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8060 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8061 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8062 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8063 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]8064</pre>
8065
8066<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8067 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8068 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8069 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8070 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]8071</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8072
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8073<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]8074<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8075 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
8076 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8077
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8078<h5>Arguments:</h5>
8079<p>These intrinsics take two arguments, the first a pointer to an integer value
8080 and the second an integer value. The result is also an integer value. These
8081 integer types can have any bit width, but they must all have the same bit
8082 width. The targets may only lower integer representations they support.</p>
8083
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8084<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8085<p>These intrinsics does a series of operations atomically. They first load the
8086 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
8087 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
8088 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8089
8090<h5>Examples:</h5>
8091<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]8092%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8093%ptr = bitcast i8* %mallocP to i32*
8094 store i32 7, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8095%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8096 <i>; yields {i32}:result0 = 7</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8097%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8098 <i>; yields {i32}:result1 = -2</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8099%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8100 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8101%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8102 <i>; yields {i32}:result3 = 8</i>
8103%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
8104</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8105
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8106</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]8107
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8108</div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8109
8110<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8111<h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8112 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8113</h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8114
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8115<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8116
8117<p>This class of intrinsics exists to information about the lifetime of memory
8118 objects and ranges where variables are immutable.</p>
8119
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8120<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8121<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8122 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8123</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8124
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8125<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8126
8127<h5>Syntax:</h5>
8128<pre>
8129 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8130</pre>
8131
8132<h5>Overview:</h5>
8133<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
8134 object's lifetime.</p>
8135
8136<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8137<p>The first argument is a constant integer representing the size of the
8138 object, or -1 if it is variable sized. The second argument is a pointer to
8139 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8140
8141<h5>Semantics:</h5>
8142<p>This intrinsic indicates that before this point in the code, the value of the
8143 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]8144 never be used and has an undefined value. A load from the pointer that
8145 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8146 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
8147
8148</div>
8149
8150<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8151<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8152 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8153</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8154
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8155<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8156
8157<h5>Syntax:</h5>
8158<pre>
8159 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8160</pre>
8161
8162<h5>Overview:</h5>
8163<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
8164 object's lifetime.</p>
8165
8166<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8167<p>The first argument is a constant integer representing the size of the
8168 object, or -1 if it is variable sized. The second argument is a pointer to
8169 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8170
8171<h5>Semantics:</h5>
8172<p>This intrinsic indicates that after this point in the code, the value of the
8173 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
8174 never be used and has an undefined value. Any stores into the memory object
8175 following this intrinsic may be removed as dead.
8176
8177</div>
8178
8179<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8180<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8181 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8182</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8183
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8184<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8185
8186<h5>Syntax:</h5>
8187<pre>
Nick Lewycky29b6cb42010-11-30 04:13:41 +0000[diff] [blame]8188 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8189</pre>
8190
8191<h5>Overview:</h5>
8192<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
8193 a memory object will not change.</p>
8194
8195<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8196<p>The first argument is a constant integer representing the size of the
8197 object, or -1 if it is variable sized. The second argument is a pointer to
8198 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8199
8200<h5>Semantics:</h5>
8201<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
8202 the return value, the referenced memory location is constant and
8203 unchanging.</p>
8204
8205</div>
8206
8207<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8208<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8209 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8210</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8211
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8212<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8213
8214<h5>Syntax:</h5>
8215<pre>
8216 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8217</pre>
8218
8219<h5>Overview:</h5>
8220<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
8221 a memory object are mutable.</p>
8222
8223<h5>Arguments:</h5>
8224<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8225 The second argument is a constant integer representing the size of the
8226 object, or -1 if it is variable sized and the third argument is a pointer
8227 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8228
8229<h5>Semantics:</h5>
8230<p>This intrinsic indicates that the memory is mutable again.</p>
8231
8232</div>
8233
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8234</div>
8235
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]8236<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8237<h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8238 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8239</h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8240
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8241<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8242
8243<p>This class of intrinsics is designed to be generic and has no specific
8244 purpose.</p>
8245
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8246<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8247<h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8248 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8249</h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8250
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8251<div>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8252
8253<h5>Syntax:</h5>
8254<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8255 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]8256</pre>
8257
8258<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8259<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8260
8261<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8262<p>The first argument is a pointer to a value, the second is a pointer to a
8263 global string, the third is a pointer to a global string which is the source
8264 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8265
8266<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8267<p>This intrinsic allows annotation of local variables with arbitrary strings.
8268 This can be useful for special purpose optimizations that want to look for
8269 these annotations. These have no other defined use, they are ignored by code
8270 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8271
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8272</div>
8273
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8274<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8275<h4>
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]8276 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8277</h4>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8278
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8279<div>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8280
8281<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8282<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
8283 any integer bit width.</p>
8284
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8285<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8286 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8287 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8288 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8289 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8290 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]8291</pre>
8292
8293<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8294<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8295
8296<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8297<p>The first argument is an integer value (result of some expression), the
8298 second is a pointer to a global string, the third is a pointer to a global
8299 string which is the source file name, and the last argument is the line
8300 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8301
8302<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8303<p>This intrinsic allows annotations to be put on arbitrary expressions with
8304 arbitrary strings. This can be useful for special purpose optimizations that
8305 want to look for these annotations. These have no other defined use, they
8306 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8307
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8308</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]8309
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8310<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8311<h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8312 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8313</h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8314
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8315<div>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8316
8317<h5>Syntax:</h5>
8318<pre>
8319 declare void @llvm.trap()
8320</pre>
8321
8322<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8323<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8324
8325<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8326<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8327
8328<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8329<p>This intrinsics is lowered to the target dependent trap instruction. If the
8330 target does not have a trap instruction, this intrinsic will be lowered to
8331 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8332
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8333</div>
8334
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8335<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8336<h4>
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]8337 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8338</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8339
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8340<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8341
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8342<h5>Syntax:</h5>
8343<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8344 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8345</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8346
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8347<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8348<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8349 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8350 ensure that it is placed on the stack before local variables.</p>
8351
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8352<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8353<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8354 arguments. The first argument is the value loaded from the stack
8355 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8356 that has enough space to hold the value of the guard.</p>
8357
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8358<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8359<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8360 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8361 stack. This is to ensure that if a local variable on the stack is
8362 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8363 the guard on the stack is checked against the original guard. If they are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8364 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8365 function.</p>
8366
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8367</div>
8368
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8369<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8370<h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8371 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8372</h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8373
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8374<div>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8375
8376<h5>Syntax:</h5>
8377<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8378 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8379 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8380</pre>
8381
8382<h5>Overview:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8383<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8384 the optimizers to determine at compile time whether a) an operation (like
8385 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8386 runtime check for overflow isn't necessary. An object in this context means
8387 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8388
8389<h5>Arguments:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8390<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]8391 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8392 is a boolean 0 or 1. This argument determines whether you want the
8393 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]8394 1, variables are not allowed.</p>
8395
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8396<h5>Semantics:</h5>
8397<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8398 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8399 depending on the <tt>type</tt> argument, if the size cannot be determined at
8400 compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8401
8402</div>
8403
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8404</div>
8405
8406</div>
8407
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8408<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8409<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8410<address>
8411 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]8412 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8413 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]8414 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8415
8416 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]8417 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8418 Last modified: $Date$
8419</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]8420
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]8421</body>
8422</html>