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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 6445ecbdb9caea8269ecb62e8dce13fe25238247 / . / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
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7 <meta name="author" content="Chris Lattner">
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]8 <meta name="description"
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]14
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]15<h1>LLVM Language Reference Manual</h1>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]27 <li><a href="#linkage_linker_private_weak">'<tt>linker_private_weak</tt>' Linkage</a></li>
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]28 <li><a href="#linkage_linker_private_weak_def_auto">'<tt>linker_private_weak_def_auto</tt>' Linkage</a></li>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]29 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
30 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
31 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
32 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
33 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
34 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
35 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
Chris Lattner5a2d8752009-10-10 18:26:06 +0000[diff] [blame]36 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]37 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
38 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
39 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
40 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]41 </ol>
42 </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]43 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]44 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]45 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]46 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]47 <li><a href="#aliasstructure">Aliases</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]48 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]49 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]50 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]51 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]52 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]53 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]54 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]55 <li><a href="#volatile">Volatile Memory Accesses</a></li>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]56 <li><a href="#memmodel">Memory Model for Concurrent Operations</a></li>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]57 <li><a href="#ordering">Atomic Memory Ordering Constraints</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]58 </ol>
59 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]60 <li><a href="#typesystem">Type System</a>
61 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]62 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]63 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]64 <ol>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]65 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]66 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]67 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]68 <li><a href="#t_void">Void Type</a></li>
69 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]70 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]71 </ol>
72 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]73 <li><a href="#t_derived">Derived Types</a>
74 <ol>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]75 <li><a href="#t_aggregate">Aggregate Types</a>
76 <ol>
77 <li><a href="#t_array">Array Type</a></li>
78 <li><a href="#t_struct">Structure Type</a></li>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]79 <li><a href="#t_opaque">Opaque Structure Types</a></li>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]80 <li><a href="#t_vector">Vector Type</a></li>
81 </ol>
82 </li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]83 <li><a href="#t_function">Function Type</a></li>
84 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]85 </ol>
86 </li>
87 </ol>
88 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]89 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]90 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]91 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]92 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]93 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
94 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]95 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]96 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]97 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]98 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]99 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]100 <li><a href="#othervalues">Other Values</a>
101 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]102 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]103 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]104 </ol>
105 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]106 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
107 <ol>
108 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]109 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
110 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]111 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
112 Global Variable</a></li>
113 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
114 Global Variable</a></li>
115 </ol>
116 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]117 <li><a href="#instref">Instruction Reference</a>
118 <ol>
119 <li><a href="#terminators">Terminator Instructions</a>
120 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]121 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
122 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]123 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]124 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]125 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]126 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]127 <li><a href="#i_resume">'<tt>resume</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]128 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]129 </ol>
130 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]131 <li><a href="#binaryops">Binary Operations</a>
132 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]133 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]134 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]135 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]136 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]137 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]138 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]139 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
140 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
141 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]142 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
143 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
144 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]145 </ol>
146 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]147 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
148 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]149 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
150 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
151 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]152 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]153 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]154 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]155 </ol>
156 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]157 <li><a href="#vectorops">Vector Operations</a>
158 <ol>
159 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
160 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
161 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]162 </ol>
163 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]164 <li><a href="#aggregateops">Aggregate Operations</a>
165 <ol>
166 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
167 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
168 </ol>
169 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]170 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]171 <ol>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]172 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
173 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
174 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
175 <li><a href="#i_fence">'<tt>fence</tt>' Instruction</a></li>
176 <li><a href="#i_cmpxchg">'<tt>cmpxchg</tt>' Instruction</a></li>
177 <li><a href="#i_atomicrmw">'<tt>atomicrmw</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]178 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]179 </ol>
180 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]181 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]182 <ol>
183 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
184 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
185 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
186 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
187 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]188 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
189 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
190 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
191 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]192 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
193 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]194 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]195 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]196 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]197 <li><a href="#otherops">Other Operations</a>
198 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]199 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
200 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]201 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]202 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]203 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]204 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
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>.
Bill Wendling0246bb72011-07-31 06:45:03 +0000[diff] [blame]1528 <li>If <var>R<sub>byte</sub></var> happens before
1529 <var>write<sub>3</sub></var>, then <var>R<sub>byte</sub></var> does not
1530 see <var>write<sub>3</sub></var>.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]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 Friedman101c81d2011-08-02 01:15:34 +0000[diff] [blame]1558otherwise be stored is not allowed in general. (Specifically, in the case
1559where another thread might write to and read from an address, introducing a
1560store can change a load that may see exactly one write into a load that may
1561see 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
Bill Wendlingaf75f0c2011-07-31 06:47:33 +0000[diff] [blame]2189</div>
2190
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2191<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2192<h2><a name="constants">Constants</a></h2>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2193<!-- *********************************************************************** -->
2194
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2195<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2196
2197<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2198 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2199
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2200<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2201<h3>
2202 <a name="simpleconstants">Simple Constants</a>
2203</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2204
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2205<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2206
2207<dl>
2208 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2209 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]2210 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2211
2212 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2213 <dd>Standard integers (such as '4') are constants of
2214 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2215 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2216
2217 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2218 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2219 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2220 notation (see below). The assembler requires the exact decimal value of a
2221 floating-point constant. For example, the assembler accepts 1.25 but
2222 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2223 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2224
2225 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2226 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2227 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2228</dl>
2229
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2230<p>The one non-intuitive notation for constants is the hexadecimal form of
2231 floating point constants. For example, the form '<tt>double
2232 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2233 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2234 constants are required (and the only time that they are generated by the
2235 disassembler) is when a floating point constant must be emitted but it cannot
2236 be represented as a decimal floating point number in a reasonable number of
2237 digits. For example, NaN's, infinities, and other special values are
2238 represented in their IEEE hexadecimal format so that assembly and disassembly
2239 do not cause any bits to change in the constants.</p>
2240
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]2241<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2242 represented using the 16-digit form shown above (which matches the IEEE754
2243 representation for double); float values must, however, be exactly
2244 representable as IEE754 single precision. Hexadecimal format is always used
2245 for long double, and there are three forms of long double. The 80-bit format
2246 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2247 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2248 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2249 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2250 currently supported target uses this format. Long doubles will only work if
2251 they match the long double format on your target. All hexadecimal formats
2252 are big-endian (sign bit at the left).</p>
2253
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]2254<p>There are no constants of type x86mmx.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2255</div>
2256
2257<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2258<h3>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2259<a name="aggregateconstants"></a> <!-- old anchor -->
2260<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2261</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2262
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2263<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2264
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2265<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2266 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2267
2268<dl>
2269 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2270 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2271 type definitions (a comma separated list of elements, surrounded by braces
2272 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2273 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2274 Structure constants must have <a href="#t_struct">structure type</a>, and
2275 the number and types of elements must match those specified by the
2276 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2277
2278 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2279 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2280 definitions (a comma separated list of elements, surrounded by square
2281 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2282 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2283 the number and types of elements must match those specified by the
2284 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2285
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2286 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2287 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2288 definitions (a comma separated list of elements, surrounded by
2289 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2290 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2291 have <a href="#t_vector">vector type</a>, and the number and types of
2292 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2293
2294 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2295 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2296 value to zero of <em>any</em> type, including scalar and
2297 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2298 This is often used to avoid having to print large zero initializers
2299 (e.g. for large arrays) and is always exactly equivalent to using explicit
2300 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2301
2302 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2303 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2304 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2305 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2306 be interpreted as part of the instruction stream, metadata is a place to
2307 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2308</dl>
2309
2310</div>
2311
2312<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2313<h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2314 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2315</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2316
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2317<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2318
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2319<p>The addresses of <a href="#globalvars">global variables</a>
2320 and <a href="#functionstructure">functions</a> are always implicitly valid
2321 (link-time) constants. These constants are explicitly referenced when
2322 the <a href="#identifiers">identifier for the global</a> is used and always
2323 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2324 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2325
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2326<pre class="doc_code">
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2327@X = global i32 17
2328@Y = global i32 42
2329@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2330</pre>
2331
2332</div>
2333
2334<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2335<h3>
2336 <a name="undefvalues">Undefined Values</a>
2337</h3>
2338
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2339<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2340
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2341<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]2342 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2343 Undefined values may be of any type (other than '<tt>label</tt>'
2344 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2345
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2346<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2347 program is well defined no matter what value is used. This gives the
2348 compiler more freedom to optimize. Here are some examples of (potentially
2349 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2350
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2351
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2352<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2353 %A = add %X, undef
2354 %B = sub %X, undef
2355 %C = xor %X, undef
2356Safe:
2357 %A = undef
2358 %B = undef
2359 %C = undef
2360</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2361
2362<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]2363 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]2364
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2365<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2366 %A = or %X, undef
2367 %B = and %X, undef
2368Safe:
2369 %A = -1
2370 %B = 0
2371Unsafe:
2372 %A = undef
2373 %B = undef
2374</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2375
2376<p>These logical operations have bits that are not always affected by the input.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2377 For example, if <tt>%X</tt> has a zero bit, then the output of the
2378 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2379 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2380 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2381 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2382 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2383 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2384 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2385
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2386<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2387 %A = select undef, %X, %Y
2388 %B = select undef, 42, %Y
2389 %C = select %X, %Y, undef
2390Safe:
2391 %A = %X (or %Y)
2392 %B = 42 (or %Y)
2393 %C = %Y
2394Unsafe:
2395 %A = undef
2396 %B = undef
2397 %C = undef
2398</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2399
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2400<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2401 branch) conditions can go <em>either way</em>, but they have to come from one
2402 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2403 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2404 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2405 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2406 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2407 eliminated.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2408
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2409<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2410 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2411
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2412 %B = undef
2413 %C = xor %B, %B
2414
2415 %D = undef
2416 %E = icmp lt %D, 4
2417 %F = icmp gte %D, 4
2418
2419Safe:
2420 %A = undef
2421 %B = undef
2422 %C = undef
2423 %D = undef
2424 %E = undef
2425 %F = undef
2426</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2427
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2428<p>This example points out that two '<tt>undef</tt>' operands are not
2429 necessarily the same. This can be surprising to people (and also matches C
2430 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2431 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2432 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2433 its value over its "live range". This is true because the variable doesn't
2434 actually <em>have a live range</em>. Instead, the value is logically read
2435 from arbitrary registers that happen to be around when needed, so the value
2436 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2437 need to have the same semantics or the core LLVM "replace all uses with"
2438 concept would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2439
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2440<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2441 %A = fdiv undef, %X
2442 %B = fdiv %X, undef
2443Safe:
2444 %A = undef
2445b: unreachable
2446</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2447
2448<p>These examples show the crucial difference between an <em>undefined
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2449 value</em> and <em>undefined behavior</em>. An undefined value (like
2450 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2451 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2452 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2453 defined on SNaN's. However, in the second example, we can make a more
2454 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2455 arbitrary value, we are allowed to assume that it could be zero. Since a
2456 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2457 the operation does not execute at all. This allows us to delete the divide and
2458 all code after it. Because the undefined operation "can't happen", the
2459 optimizer can assume that it occurs in dead code.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2460
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2461<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2462a: store undef -> %X
2463b: store %X -> undef
2464Safe:
2465a: &lt;deleted&gt;
2466b: unreachable
2467</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2468
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2469<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2470 undefined value can be assumed to not have any effect; we can assume that the
2471 value is overwritten with bits that happen to match what was already there.
2472 However, a store <em>to</em> an undefined location could clobber arbitrary
2473 memory, therefore, it has undefined behavior.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2474
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2475</div>
2476
2477<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2478<h3>
2479 <a name="trapvalues">Trap Values</a>
2480</h3>
2481
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2482<div>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2483
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2484<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2485 instead of representing an unspecified bit pattern, they represent the
2486 fact that an instruction or constant expression which cannot evoke side
2487 effects has nevertheless detected a condition which results in undefined
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2488 behavior.</p>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2489
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2490<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]2491 only exist when produced by operations such as
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2492 <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]2493
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2494<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2495
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2496<ul>
2497<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2498 their operands.</li>
2499
2500<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2501 to their dynamic predecessor basic block.</li>
2502
2503<li>Function arguments depend on the corresponding actual argument values in
2504 the dynamic callers of their functions.</li>
2505
2506<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2507 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2508 control back to them.</li>
2509
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2510<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2511 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2512 or exception-throwing call instructions that dynamically transfer control
2513 back to them.</li>
2514
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2515<li>Non-volatile loads and stores depend on the most recent stores to all of the
2516 referenced memory addresses, following the order in the IR
2517 (including loads and stores implied by intrinsics such as
2518 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2519
Dan Gohman7c24ff12010-05-03 14:59:34 +0000[diff] [blame]2520<!-- TODO: In the case of multiple threads, this only applies if the store
2521 "happens-before" the load or store. -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2522
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2523<!-- TODO: floating-point exception state -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2524
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2525<li>An instruction with externally visible side effects depends on the most
2526 recent preceding instruction with externally visible side effects, following
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]2527 the order in the IR. (This includes
2528 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2529
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2530<li>An instruction <i>control-depends</i> on a
2531 <a href="#terminators">terminator instruction</a>
2532 if the terminator instruction has multiple successors and the instruction
2533 is always executed when control transfers to one of the successors, and
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2534 may not be executed when control is transferred to another.</li>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2535
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2536<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2537 instruction if the set of instructions it otherwise depends on would be
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2538 different if the terminator had transferred control to a different
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2539 successor.</li>
2540
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2541<li>Dependence is transitive.</li>
2542
2543</ul>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2544
2545<p>Whenever a trap value is generated, all values which depend on it evaluate
2546 to trap. If they have side effects, the evoke their side effects as if each
2547 operand with a trap value were undef. If they have externally-visible side
2548 effects, the behavior is undefined.</p>
2549
2550<p>Here are some examples:</p>
Dan Gohmanc30f6e12010-04-26 20:54:53 +0000[diff] [blame]2551
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2552<pre class="doc_code">
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2553entry:
2554 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2555 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2556 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2557 store i32 0, i32* %trap_yet_again ; undefined behavior
2558
2559 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2560 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2561
2562 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2563
2564 %narrowaddr = bitcast i32* @g to i16*
2565 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2566 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2567 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2568
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2569 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2570 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2571
2572true:
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2573 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2574 ; it has undefined behavior.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2575 br label %end
2576
2577end:
2578 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2579 ; Both edges into this PHI are
2580 ; control-dependent on %cmp, so this
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2581 ; always results in a trap value.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2582
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2583 volatile store i32 0, i32* @g ; This would depend on the store in %true
2584 ; if %cmp is true, or the store in %entry
2585 ; otherwise, so this is undefined behavior.
2586
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2587 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2588 ; The same branch again, but this time the
2589 ; true block doesn't have side effects.
2590
2591second_true:
2592 ; No side effects!
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2593 ret void
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2594
2595second_end:
2596 volatile store i32 0, i32* @g ; This time, the instruction always depends
2597 ; on the store in %end. Also, it is
2598 ; control-equivalent to %end, so this is
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2599 ; well-defined (again, ignoring earlier
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2600 ; undefined behavior in this example).
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2601</pre>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2602
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2603</div>
2604
2605<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2606<h3>
2607 <a name="blockaddress">Addresses of Basic Blocks</a>
2608</h3>
2609
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2610<div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2611
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2612<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2613
2614<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2615 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2616 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2617
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2618<p>This value only has defined behavior when used as an operand to the
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2619 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2620 comparisons against null. Pointer equality tests between labels addresses
2621 results in undefined behavior &mdash; though, again, comparison against null
2622 is ok, and no label is equal to the null pointer. This may be passed around
2623 as an opaque pointer sized value as long as the bits are not inspected. This
2624 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2625 long as the original value is reconstituted before the <tt>indirectbr</tt>
2626 instruction.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2627
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2628<p>Finally, some targets may provide defined semantics when using the value as
2629 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2630
2631</div>
2632
2633
2634<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2635<h3>
2636 <a name="constantexprs">Constant Expressions</a>
2637</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2638
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2639<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2640
2641<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2642 to be used as constants. Constant expressions may be of
2643 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2644 operation that does not have side effects (e.g. load and call are not
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2645 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2646
2647<dl>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2648 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2649 <dd>Truncate a constant to another type. The bit size of CST must be larger
2650 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2651
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2652 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2653 <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]2654 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2655
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2656 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2657 <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]2658 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2659
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2660 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2661 <dd>Truncate a floating point constant to another floating point type. The
2662 size of CST must be larger than the size of TYPE. Both types must be
2663 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2664
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2665 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2666 <dd>Floating point extend a constant to another type. The size of CST must be
2667 smaller or equal to the size of TYPE. Both types must be floating
2668 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2669
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2670 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2671 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2672 constant. TYPE must be a scalar or vector integer type. CST must be of
2673 scalar or vector floating point type. Both CST and TYPE must be scalars,
2674 or vectors of the same number of elements. If the value won't fit in the
2675 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2676
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2677 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2678 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2679 constant. TYPE must be a scalar or vector integer type. CST must be of
2680 scalar or vector floating point type. Both CST and TYPE must be scalars,
2681 or vectors of the same number of elements. If the value won't fit in the
2682 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2683
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2684 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2685 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2686 constant. TYPE must be a scalar or vector floating point type. CST must be
2687 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2688 vectors of the same number of elements. If the value won't fit in the
2689 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2690
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2691 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2692 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2693 constant. TYPE must be a scalar or vector floating point type. CST must be
2694 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2695 vectors of the same number of elements. If the value won't fit in the
2696 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2697
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2698 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2699 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2700 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2701 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2702 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2703
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2704 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2705 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2706 type. CST must be of integer type. The CST value is zero extended,
2707 truncated, or unchanged to make it fit in a pointer size. This one is
2708 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2709
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2710 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2711 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2712 are the same as those for the <a href="#i_bitcast">bitcast
2713 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2714
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2715 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2716 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2717 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2718 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2719 instruction, the index list may have zero or more indexes, which are
2720 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2721
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2722 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2723 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2724
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2725 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2726 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2727
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2728 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2729 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2730
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2731 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2732 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2733 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2734
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2735 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2736 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2737 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2738
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2739 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2740 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2741 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2742
Nick Lewycky9e130ce2010-05-29 06:44:15 +0000[diff] [blame]2743 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2744 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2745 constants. The index list is interpreted in a similar manner as indices in
2746 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2747 index value must be specified.</dd>
2748
2749 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2750 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2751 constants. The index list is interpreted in a similar manner as indices in
2752 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2753 index value must be specified.</dd>
2754
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2755 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2756 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2757 be any of the <a href="#binaryops">binary</a>
2758 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2759 on operands are the same as those for the corresponding instruction
2760 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2761</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2762
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2763</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2764
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2765</div>
2766
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2767<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2768<h2><a name="othervalues">Other Values</a></h2>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2769<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2770<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2771<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2772<h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2773<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2774</h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2775
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2776<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2777
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2778<p>LLVM supports inline assembler expressions (as opposed
2779 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2780 a special value. This value represents the inline assembler as a string
2781 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2782 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2783 expression has side effects, and a flag indicating whether the function
2784 containing the asm needs to align its stack conservatively. An example
2785 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2786
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2787<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2788i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2789</pre>
2790
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2791<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2792 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2793 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2794
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2795<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2796%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]2797</pre>
2798
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2799<p>Inline asms with side effects not visible in the constraint list must be
2800 marked as having side effects. This is done through the use of the
2801 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2802
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2803<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2804call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2805</pre>
2806
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2807<p>In some cases inline asms will contain code that will not work unless the
2808 stack is aligned in some way, such as calls or SSE instructions on x86,
2809 yet will not contain code that does that alignment within the asm.
2810 The compiler should make conservative assumptions about what the asm might
2811 contain and should generate its usual stack alignment code in the prologue
2812 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2813
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2814<pre class="doc_code">
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2815call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2816</pre>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2817
2818<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2819 first.</p>
2820
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2821<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2822 documented here. Constraints on what can be done (e.g. duplication, moving,
2823 etc need to be documented). This is probably best done by reference to
2824 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2825
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2826<h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2827<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2828</h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2829
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2830<div>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2831
2832<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2833 attached to it that contains a list of constant integers. If present, the
2834 code generator will use the integer as the location cookie value when report
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2835 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]2836 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2837 source code that produced it. For example:</p>
2838
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2839<pre class="doc_code">
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2840call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2841...
2842!42 = !{ i32 1234567 }
2843</pre>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2844
2845<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]2846 IR. If the MDNode contains multiple constants, the code generator will use
2847 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]2848
2849</div>
2850
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2851</div>
2852
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2853<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2854<h3>
2855 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2856</h3>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2857
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2858<div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2859
2860<p>LLVM IR allows metadata to be attached to instructions in the program that
2861 can convey extra information about the code to the optimizers and code
2862 generator. One example application of metadata is source-level debug
2863 information. There are two metadata primitives: strings and nodes. All
2864 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2865 preceding exclamation point ('<tt>!</tt>').</p>
2866
2867<p>A metadata string is a string surrounded by double quotes. It can contain
2868 any character by escaping non-printable characters with "\xx" where "xx" is
2869 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2870
2871<p>Metadata nodes are represented with notation similar to structure constants
2872 (a comma separated list of elements, surrounded by braces and preceded by an
2873 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2874 10}</tt>". Metadata nodes can have any values as their operand.</p>
2875
2876<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2877 metadata nodes, which can be looked up in the module symbol table. For
2878 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2879
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2880<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2881 function is using two metadata arguments.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2882
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2883<div class="doc_code">
2884<pre>
2885call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2886</pre>
2887</div>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2888
2889<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2890 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2891
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2892<div class="doc_code">
2893<pre>
2894%indvar.next = add i64 %indvar, 1, !dbg !21
2895</pre>
2896</div>
2897
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2898</div>
2899
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2900</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2901
2902<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2903<h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2904 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2905</h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2906<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2907<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2908<p>LLVM has a number of "magic" global variables that contain data that affect
2909code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2910of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2911section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2912by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2913
2914<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2915<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2916<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2917</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2918
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2919<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2920
2921<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2922href="#linkage_appending">appending linkage</a>. This array contains a list of
2923pointers to global variables and functions which may optionally have a pointer
2924cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2925
2926<pre>
2927 @X = global i8 4
2928 @Y = global i32 123
2929
2930 @llvm.used = appending global [2 x i8*] [
2931 i8* @X,
2932 i8* bitcast (i32* @Y to i8*)
2933 ], section "llvm.metadata"
2934</pre>
2935
2936<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2937compiler, assembler, and linker are required to treat the symbol as if there is
2938a reference to the global that it cannot see. For example, if a variable has
2939internal linkage and no references other than that from the <tt>@llvm.used</tt>
2940list, it cannot be deleted. This is commonly used to represent references from
2941inline asms and other things the compiler cannot "see", and corresponds to
2942"attribute((used))" in GNU C.</p>
2943
2944<p>On some targets, the code generator must emit a directive to the assembler or
2945object file to prevent the assembler and linker from molesting the symbol.</p>
2946
2947</div>
2948
2949<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2950<h3>
2951 <a name="intg_compiler_used">
2952 The '<tt>llvm.compiler.used</tt>' Global Variable
2953 </a>
2954</h3>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2955
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2956<div>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2957
2958<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2959<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2960touching the symbol. On targets that support it, this allows an intelligent
2961linker to optimize references to the symbol without being impeded as it would be
2962by <tt>@llvm.used</tt>.</p>
2963
2964<p>This is a rare construct that should only be used in rare circumstances, and
2965should not be exposed to source languages.</p>
2966
2967</div>
2968
2969<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2970<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2971<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2972</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2973
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2974<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2975<pre>
2976%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2977@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2978</pre>
2979<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.
2980</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2981
2982</div>
2983
2984<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2985<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2986<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2987</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2988
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2989<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2990<pre>
2991%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2992@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2993</pre>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2994
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2995<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.
2996</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2997
2998</div>
2999
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3000</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]3001
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]3002<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3003<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3004<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3005
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3006<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3007
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3008<p>The LLVM instruction set consists of several different classifications of
3009 instructions: <a href="#terminators">terminator
3010 instructions</a>, <a href="#binaryops">binary instructions</a>,
3011 <a href="#bitwiseops">bitwise binary instructions</a>,
3012 <a href="#memoryops">memory instructions</a>, and
3013 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3014
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3015<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3016<h3>
3017 <a name="terminators">Terminator Instructions</a>
3018</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3019
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3020<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3021
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3022<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
3023 in a program ends with a "Terminator" instruction, which indicates which
3024 block should be executed after the current block is finished. These
3025 terminator instructions typically yield a '<tt>void</tt>' value: they produce
3026 control flow, not values (the one exception being the
3027 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
3028
Chris Lattner6445ecb2011-08-02 20:29:13 +0000[diff] [blame^]3029<p>The terminator instructions are:
3030 '<a href="#i_ret"><tt>ret</tt></a>',
3031 '<a href="#i_br"><tt>br</tt></a>',
3032 '<a href="#i_switch"><tt>switch</tt></a>',
3033 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>',
3034 '<a href="#i_invoke"><tt>invoke</tt></a>',
3035 '<a href="#i_unwind"><tt>unwind</tt></a>',
3036 '<a href="#i_resume"><tt>resume</tt></a>', and
3037 '<a href="#i_unreachable"><tt>unreachable</tt></a>'.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3038
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3039<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3040<h4>
3041 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
3042</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3043
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3044<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3045
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3046<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]3047<pre>
3048 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]3049 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3050</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3051
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3052<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3053<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
3054 a value) from a function back to the caller.</p>
3055
3056<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
3057 value and then causes control flow, and one that just causes control flow to
3058 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3059
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3060<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3061<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
3062 return value. The type of the return value must be a
3063 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]3064
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3065<p>A function is not <a href="#wellformed">well formed</a> if it it has a
3066 non-void return type and contains a '<tt>ret</tt>' instruction with no return
3067 value or a return value with a type that does not match its type, or if it
3068 has a void return type and contains a '<tt>ret</tt>' instruction with a
3069 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3070
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3071<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3072<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
3073 the calling function's context. If the caller is a
3074 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
3075 instruction after the call. If the caller was an
3076 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
3077 the beginning of the "normal" destination block. If the instruction returns
3078 a value, that value shall set the call or invoke instruction's return
3079 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3080
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3081<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3082<pre>
3083 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3084 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]3085 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]3086</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3087
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3088</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3089<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3090<h4>
3091 <a name="i_br">'<tt>br</tt>' Instruction</a>
3092</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3093
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3094<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3095
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3096<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3097<pre>
Bill Wendlingb3aa4712011-07-26 10:41:15 +0000[diff] [blame]3098 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;
3099 br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3100</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3101
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3102<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3103<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3104 different basic block in the current function. There are two forms of this
3105 instruction, corresponding to a conditional branch and an unconditional
3106 branch.</p>
3107
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3108<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3109<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3110 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3111 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3112 target.</p>
3113
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3114<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3115<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3116 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3117 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3118 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3119
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3120<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]3121<pre>
3122Test:
3123 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3124 br i1 %cond, label %IfEqual, label %IfUnequal
3125IfEqual:
3126 <a href="#i_ret">ret</a> i32 1
3127IfUnequal:
3128 <a href="#i_ret">ret</a> i32 0
3129</pre>
3130
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3131</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3132
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3133<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3134<h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3135 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3136</h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3137
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3138<div>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3139
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3140<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3141<pre>
3142 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3143</pre>
3144
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3145<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3146<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]3147 several different places. It is a generalization of the '<tt>br</tt>'
3148 instruction, allowing a branch to occur to one of many possible
3149 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3150
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3151<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3152<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3153 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3154 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3155 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3156
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3157<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3158<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3159 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3160 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]3161 transferred to the corresponding destination; otherwise, control flow is
3162 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3163
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3164<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3165<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3166 <tt>switch</tt> instruction, this instruction may be code generated in
3167 different ways. For example, it could be generated as a series of chained
3168 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3169
3170<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3171<pre>
3172 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3173 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3174 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3175
3176 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3177 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3178
3179 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3180 switch i32 %val, label %otherwise [ i32 0, label %onzero
3181 i32 1, label %onone
3182 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3183</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3184
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3185</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3186
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3187
3188<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3189<h4>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3190 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3191</h4>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3192
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3193<div>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3194
3195<h5>Syntax:</h5>
3196<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3197 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]3198</pre>
3199
3200<h5>Overview:</h5>
3201
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3202<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3203 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]3204 "<tt>address</tt>". Address must be derived from a <a
3205 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3206
3207<h5>Arguments:</h5>
3208
3209<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3210 rest of the arguments indicate the full set of possible destinations that the
3211 address may point to. Blocks are allowed to occur multiple times in the
3212 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3213
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3214<p>This destination list is required so that dataflow analysis has an accurate
3215 understanding of the CFG.</p>
3216
3217<h5>Semantics:</h5>
3218
3219<p>Control transfers to the block specified in the address argument. All
3220 possible destination blocks must be listed in the label list, otherwise this
3221 instruction has undefined behavior. This implies that jumps to labels
3222 defined in other functions have undefined behavior as well.</p>
3223
3224<h5>Implementation:</h5>
3225
3226<p>This is typically implemented with a jump through a register.</p>
3227
3228<h5>Example:</h5>
3229<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3230 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3231</pre>
3232
3233</div>
3234
3235
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3236<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3237<h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3238 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3239</h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3240
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3241<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3242
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3243<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3244<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3245 &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]3246 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3247</pre>
3248
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3249<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3250<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3251 function, with the possibility of control flow transfer to either the
3252 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3253 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3254 control flow will return to the "normal" label. If the callee (or any
3255 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3256 instruction, control is interrupted and continued at the dynamically nearest
3257 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3258
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3259<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3260<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3261
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3262<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3263 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3264 convention</a> the call should use. If none is specified, the call
3265 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3266
3267 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3268 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3269 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3270
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3271 <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]3272 function value being invoked. In most cases, this is a direct function
3273 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3274 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3275
3276 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3277 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3278
3279 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]3280 signature argument types and parameter attributes. All arguments must be
3281 of <a href="#t_firstclass">first class</a> type. If the function
3282 signature indicates the function accepts a variable number of arguments,
3283 the extra arguments can be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3284
3285 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3286 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3287
3288 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3289 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3290
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3291 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3292 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3293 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3294</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3295
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3296<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3297<p>This instruction is designed to operate as a standard
3298 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3299 primary difference is that it establishes an association with a label, which
3300 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3301
3302<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3303 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3304 exception. Additionally, this is important for implementation of
3305 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3306
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3307<p>For the purposes of the SSA form, the definition of the value returned by the
3308 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3309 block to the "normal" label. If the callee unwinds then no return value is
3310 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]3311
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3312<p>Note that the code generator does not yet completely support unwind, and
3313that the invoke/unwind semantics are likely to change in future versions.</p>
3314
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3315<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3316<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3317 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3318 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3319 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3320 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3321</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3322
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3323</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3324
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3325<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3326
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3327<h4>
3328 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3329</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3330
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3331<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3332
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3333<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3334<pre>
3335 unwind
3336</pre>
3337
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3338<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3339<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3340 at the first callee in the dynamic call stack which used
3341 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3342 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3343
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3344<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3345<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3346 immediately halt. The dynamic call stack is then searched for the
3347 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3348 Once found, execution continues at the "exceptional" destination block
3349 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3350 instruction in the dynamic call chain, undefined behavior results.</p>
3351
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3352<p>Note that the code generator does not yet completely support unwind, and
3353that the invoke/unwind semantics are likely to change in future versions.</p>
3354
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3355</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3356
Bill Wendlingdccc03b2011-07-31 06:30:59 +0000[diff] [blame]3357 <!-- _______________________________________________________________________ -->
3358
3359<h4>
3360 <a name="i_resume">'<tt>resume</tt>' Instruction</a>
3361</h4>
3362
3363<div>
3364
3365<h5>Syntax:</h5>
3366<pre>
3367 resume &lt;type&gt; &lt;value&gt;
3368</pre>
3369
3370<h5>Overview:</h5>
3371<p>The '<tt>resume</tt>' instruction is a terminator instruction that has no
3372 successors.</p>
3373
3374<h5>Arguments:</h5>
3375<p>The '<tt>resume</tt>' instruction's argument must have the same type as the
3376 result of any '<tt>landingpad</tt>' instruction in the same function.</p>
3377
3378<h5>Semantics:</h5>
3379<p>The '<tt>resume</tt>' instruction resumes propagation of an existing
3380 (in-flight) exception whose unwinding was interrupted with
3381 a landingpad instruction.</p>
3382
3383<h5>Example:</h5>
3384<pre>
3385 resume { i8*, i32 } %exn
3386</pre>
3387
3388</div>
3389
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3390<!-- _______________________________________________________________________ -->
3391
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3392<h4>
3393 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3394</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3395
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3396<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3397
3398<h5>Syntax:</h5>
3399<pre>
3400 unreachable
3401</pre>
3402
3403<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3404<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3405 instruction is used to inform the optimizer that a particular portion of the
3406 code is not reachable. This can be used to indicate that the code after a
3407 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3408
3409<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3410<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3411
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3412</div>
3413
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3414</div>
3415
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3416<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3417<h3>
3418 <a name="binaryops">Binary Operations</a>
3419</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3420
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3421<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3422
3423<p>Binary operators are used to do most of the computation in a program. They
3424 require two operands of the same type, execute an operation on them, and
3425 produce a single value. The operands might represent multiple data, as is
3426 the case with the <a href="#t_vector">vector</a> data type. The result value
3427 has the same type as its operands.</p>
3428
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3429<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3430
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3431<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3432<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3433 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3434</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3435
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3436<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3437
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3438<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3439<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3440 &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]3441 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3442 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3443 &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]3444</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3445
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3446<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3447<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3448
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3449<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3450<p>The two arguments to the '<tt>add</tt>' instruction must
3451 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3452 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3453
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3454<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3455<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3456
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3457<p>If the sum has unsigned overflow, the result returned is the mathematical
3458 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]3459
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3460<p>Because LLVM integers use a two's complement representation, this instruction
3461 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3462
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3463<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3464 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3465 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3466 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3467 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3468
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3469<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3470<pre>
3471 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3472</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3473
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3474</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3475
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3476<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3477<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3478 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3479</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3480
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3481<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3482
3483<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3484<pre>
3485 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3486</pre>
3487
3488<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3489<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3490
3491<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3492<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3493 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3494 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3495
3496<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3497<p>The value produced is the floating point sum of the two operands.</p>
3498
3499<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3500<pre>
3501 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3502</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3503
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3504</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3505
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3506<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3507<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3508 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3509</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3510
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3511<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3512
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3513<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3514<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3515 &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]3516 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3517 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3518 &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]3519</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3520
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3521<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3522<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3523 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3524
3525<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3526 '<tt>neg</tt>' instruction present in most other intermediate
3527 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3528
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3529<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3530<p>The two arguments to the '<tt>sub</tt>' instruction must
3531 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3532 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3533
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3534<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3535<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3536
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3537<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3538 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3539 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3540
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3541<p>Because LLVM integers use a two's complement representation, this instruction
3542 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3543
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3544<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3545 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3546 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3547 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3548 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3549
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3550<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3551<pre>
3552 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3553 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3554</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3555
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3556</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3557
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3558<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3559<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3560 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3561</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3562
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3563<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3564
3565<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3566<pre>
3567 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3568</pre>
3569
3570<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3571<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3572 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3573
3574<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3575 '<tt>fneg</tt>' instruction present in most other intermediate
3576 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3577
3578<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3579<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3580 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3581 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3582
3583<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3584<p>The value produced is the floating point difference of the two operands.</p>
3585
3586<h5>Example:</h5>
3587<pre>
3588 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3589 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3590</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3591
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3592</div>
3593
3594<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3595<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3596 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3597</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3598
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3599<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3600
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3601<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3602<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3603 &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]3604 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3605 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3606 &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]3607</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3608
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3609<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3610<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3611
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3612<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3613<p>The two arguments to the '<tt>mul</tt>' instruction must
3614 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3615 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3616
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3617<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3618<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3619
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3620<p>If the result of the multiplication has unsigned overflow, the result
3621 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3622 width of the result.</p>
3623
3624<p>Because LLVM integers use a two's complement representation, and the result
3625 is the same width as the operands, this instruction returns the correct
3626 result for both signed and unsigned integers. If a full product
3627 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3628 be sign-extended or zero-extended as appropriate to the width of the full
3629 product.</p>
3630
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3631<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3632 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3633 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3634 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3635 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3636
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3637<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3638<pre>
3639 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3640</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3641
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3642</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3643
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3644<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3645<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3646 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3647</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3648
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3649<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3650
3651<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3652<pre>
3653 &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]3654</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3655
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3656<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3657<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3658
3659<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3660<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3661 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3662 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3663
3664<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3665<p>The value produced is the floating point product of the two operands.</p>
3666
3667<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3668<pre>
3669 &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]3670</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3671
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3672</div>
3673
3674<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3675<h4>
3676 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3677</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3678
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3679<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3680
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3681<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3682<pre>
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3683 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3684 &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]3685</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3686
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3687<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3688<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3689
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3690<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3691<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3692 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3693 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3694
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3695<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3696<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3697
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3698<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3699 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3700
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3701<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3702
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3703<p>If the <tt>exact</tt> keyword is present, the result value of the
3704 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3705 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3706
3707
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3708<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3709<pre>
3710 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3711</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3712
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3713</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3714
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3715<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3716<h4>
3717 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3718</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3719
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3720<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3721
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3722<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3723<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3724 &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]3725 &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]3726</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3727
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3728<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3729<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3730
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3731<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3732<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3733 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3734 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3735
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3736<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3737<p>The value produced is the signed integer quotient of the two operands rounded
3738 towards zero.</p>
3739
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3740<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3741 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3742
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3743<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3744 undefined behavior; this is a rare case, but can occur, for example, by doing
3745 a 32-bit division of -2147483648 by -1.</p>
3746
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3747<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]3748 <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]3749 be rounded.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3750
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3751<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3752<pre>
3753 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3754</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3755
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3756</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3757
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3758<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3759<h4>
3760 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3761</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3762
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3763<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3764
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3765<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3766<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3767 &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]3768</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3769
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3770<h5>Overview:</h5>
3771<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3772
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3773<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3774<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3775 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3776 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3777
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3778<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3779<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3780
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3781<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3782<pre>
3783 &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]3784</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3785
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3786</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3787
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3788<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3789<h4>
3790 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3791</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3792
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3793<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3794
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3795<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3796<pre>
3797 &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]3798</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3799
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3800<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3801<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3802 division of its two arguments.</p>
3803
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3804<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3805<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3806 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3807 values. Both arguments must have identical types.</p>
3808
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3809<h5>Semantics:</h5>
3810<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3811 This instruction always performs an unsigned division to get the
3812 remainder.</p>
3813
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3814<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3815 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3816
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3817<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3818
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3819<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3820<pre>
3821 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3822</pre>
3823
3824</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3825
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3826<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3827<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3828 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3829</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3830
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3831<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3832
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3833<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3834<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3835 &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]3836</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3837
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3838<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3839<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3840 division of its two operands. This instruction can also take
3841 <a href="#t_vector">vector</a> versions of the values in which case the
3842 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3843
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3844<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3845<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3846 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3847 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3848
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3849<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3850<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sandsdea3a5e2011-03-07 09:12:24 +0000[diff] [blame]3851 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3852 <i>modulo</i> operator (where the result is either zero or has the same sign
3853 as the divisor, <tt>op2</tt>) of a value.
3854 For more information about the difference,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3855 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3856 Math Forum</a>. For a table of how this is implemented in various languages,
3857 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3858 Wikipedia: modulo operation</a>.</p>
3859
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3860<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3861 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3862
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3863<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3864 Overflow also leads to undefined behavior; this is a rare case, but can
3865 occur, for example, by taking the remainder of a 32-bit division of
3866 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3867 lets srem be implemented using instructions that return both the result of
3868 the division and the remainder.)</p>
3869
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3870<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3871<pre>
3872 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3873</pre>
3874
3875</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3876
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3877<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3878<h4>
3879 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3880</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3881
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3882<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3883
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3884<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3885<pre>
3886 &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]3887</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3888
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3889<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3890<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3891 its two operands.</p>
3892
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3893<h5>Arguments:</h5>
3894<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3895 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3896 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3897
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3898<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3899<p>This instruction returns the <i>remainder</i> of a division. The remainder
3900 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3901
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3902<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3903<pre>
3904 &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]3905</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3906
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3907</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3908
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3909</div>
3910
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3911<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3912<h3>
3913 <a name="bitwiseops">Bitwise Binary Operations</a>
3914</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3915
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3916<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3917
3918<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3919 program. They are generally very efficient instructions and can commonly be
3920 strength reduced from other instructions. They require two operands of the
3921 same type, execute an operation on them, and produce a single value. The
3922 resulting value is the same type as its operands.</p>
3923
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3924<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3925<h4>
3926 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3927</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3928
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3929<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3930
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3931<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3932<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3933 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3934 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3935 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3936 &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]3937</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3938
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3939<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3940<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3941 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3942
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3943<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3944<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3945 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3946 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3947
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3948<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3949<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3950 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3951 is (statically or dynamically) negative or equal to or larger than the number
3952 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3953 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3954 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3955
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3956<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3957 <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]3958 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3959 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3960 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3961 they would if the shift were expressed as a mul instruction with the same
3962 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3963
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3964<h5>Example:</h5>
3965<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3966 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3967 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3968 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3969 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3970 &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]3971</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3972
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3973</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3974
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3975<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3976<h4>
3977 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3978</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3979
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3980<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3981
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3982<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3983<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3984 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3985 &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]3986</pre>
3987
3988<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3989<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3990 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3991
3992<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3993<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3994 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3995 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3996
3997<h5>Semantics:</h5>
3998<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3999 significant bits of the result will be filled with zero bits after the shift.
4000 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
4001 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
4002 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
4003 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4004
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4005<p>If the <tt>exact</tt> keyword is present, the result value of the
4006 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4007 shifted out are non-zero.</p>
4008
4009
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4010<h5>Example:</h5>
4011<pre>
4012 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
4013 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
4014 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
4015 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4016 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]4017 &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]4018</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4019
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4020</div>
4021
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]4022<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4023<h4>
4024 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
4025</h4>
4026
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4027<div>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4028
4029<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4030<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4031 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4032 &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]4033</pre>
4034
4035<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4036<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
4037 operand shifted to the right a specified number of bits with sign
4038 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4039
4040<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4041<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4042 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4043 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4044
4045<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4046<p>This instruction always performs an arithmetic shift right operation, The
4047 most significant bits of the result will be filled with the sign bit
4048 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
4049 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
4050 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
4051 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4052
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4053<p>If the <tt>exact</tt> keyword is present, the result value of the
4054 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4055 shifted out are non-zero.</p>
4056
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4057<h5>Example:</h5>
4058<pre>
4059 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
4060 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
4061 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
4062 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4063 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]4064 &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]4065</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4066
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4067</div>
4068
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4069<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4070<h4>
4071 <a name="i_and">'<tt>and</tt>' Instruction</a>
4072</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4073
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4074<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4075
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4076<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4077<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4078 &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]4079</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4080
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4081<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4082<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
4083 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4084
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4085<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4086<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4087 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4088 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4089
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4090<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4091<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4092
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4093<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4094 <tbody>
4095 <tr>
4096 <td>In0</td>
4097 <td>In1</td>
4098 <td>Out</td>
4099 </tr>
4100 <tr>
4101 <td>0</td>
4102 <td>0</td>
4103 <td>0</td>
4104 </tr>
4105 <tr>
4106 <td>0</td>
4107 <td>1</td>
4108 <td>0</td>
4109 </tr>
4110 <tr>
4111 <td>1</td>
4112 <td>0</td>
4113 <td>0</td>
4114 </tr>
4115 <tr>
4116 <td>1</td>
4117 <td>1</td>
4118 <td>1</td>
4119 </tr>
4120 </tbody>
4121</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4122
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4123<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4124<pre>
4125 &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]4126 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
4127 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4128</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4129</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4130<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4131<h4>
4132 <a name="i_or">'<tt>or</tt>' Instruction</a>
4133</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4134
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4135<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4136
4137<h5>Syntax:</h5>
4138<pre>
4139 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4140</pre>
4141
4142<h5>Overview:</h5>
4143<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4144 two operands.</p>
4145
4146<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4147<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4148 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4149 values. Both arguments must have identical types.</p>
4150
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4151<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4152<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4153
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4154<table border="1" cellspacing="0" cellpadding="4">
4155 <tbody>
4156 <tr>
4157 <td>In0</td>
4158 <td>In1</td>
4159 <td>Out</td>
4160 </tr>
4161 <tr>
4162 <td>0</td>
4163 <td>0</td>
4164 <td>0</td>
4165 </tr>
4166 <tr>
4167 <td>0</td>
4168 <td>1</td>
4169 <td>1</td>
4170 </tr>
4171 <tr>
4172 <td>1</td>
4173 <td>0</td>
4174 <td>1</td>
4175 </tr>
4176 <tr>
4177 <td>1</td>
4178 <td>1</td>
4179 <td>1</td>
4180 </tr>
4181 </tbody>
4182</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4183
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4184<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4185<pre>
4186 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4187 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4188 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4189</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4190
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4191</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4192
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4193<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4194<h4>
4195 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4196</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4197
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4198<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4199
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4200<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4201<pre>
4202 &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]4203</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4204
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4205<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4206<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4207 its two operands. The <tt>xor</tt> is used to implement the "one's
4208 complement" operation, which is the "~" operator in C.</p>
4209
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4210<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4211<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4212 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4213 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4214
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4215<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4216<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4217
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4218<table border="1" cellspacing="0" cellpadding="4">
4219 <tbody>
4220 <tr>
4221 <td>In0</td>
4222 <td>In1</td>
4223 <td>Out</td>
4224 </tr>
4225 <tr>
4226 <td>0</td>
4227 <td>0</td>
4228 <td>0</td>
4229 </tr>
4230 <tr>
4231 <td>0</td>
4232 <td>1</td>
4233 <td>1</td>
4234 </tr>
4235 <tr>
4236 <td>1</td>
4237 <td>0</td>
4238 <td>1</td>
4239 </tr>
4240 <tr>
4241 <td>1</td>
4242 <td>1</td>
4243 <td>0</td>
4244 </tr>
4245 </tbody>
4246</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4247
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4248<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4249<pre>
4250 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4251 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4252 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4253 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4254</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4255
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4256</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4257
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4258</div>
4259
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4260<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4261<h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4262 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4263</h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4264
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4265<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4266
4267<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4268 target-independent manner. These instructions cover the element-access and
4269 vector-specific operations needed to process vectors effectively. While LLVM
4270 does directly support these vector operations, many sophisticated algorithms
4271 will want to use target-specific intrinsics to take full advantage of a
4272 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4273
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4274<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4275<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4276 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4277</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4278
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4279<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4280
4281<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4282<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4283 &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]4284</pre>
4285
4286<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4287<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4288 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4289
4290
4291<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4292<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4293 of <a href="#t_vector">vector</a> type. The second operand is an index
4294 indicating the position from which to extract the element. The index may be
4295 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4296
4297<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4298<p>The result is a scalar of the same type as the element type of
4299 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4300 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4301 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4302
4303<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4304<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4305 &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]4306</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4307
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4308</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4309
4310<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4311<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4312 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4313</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4314
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4315<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4316
4317<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4318<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]4319 &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]4320</pre>
4321
4322<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4323<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4324 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4325
4326<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4327<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4328 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4329 whose type must equal the element type of the first operand. The third
4330 operand is an index indicating the position at which to insert the value.
4331 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4332
4333<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4334<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4335 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4336 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4337 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4338
4339<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4340<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4341 &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]4342</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4343
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4344</div>
4345
4346<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4347<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4348 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4349</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4350
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4351<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4352
4353<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4354<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4355 &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]4356</pre>
4357
4358<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4359<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4360 from two input vectors, returning a vector with the same element type as the
4361 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4362
4363<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4364<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4365 with types that match each other. The third argument is a shuffle mask whose
4366 element type is always 'i32'. The result of the instruction is a vector
4367 whose length is the same as the shuffle mask and whose element type is the
4368 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4369
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4370<p>The shuffle mask operand is required to be a constant vector with either
4371 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4372
4373<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4374<p>The elements of the two input vectors are numbered from left to right across
4375 both of the vectors. The shuffle mask operand specifies, for each element of
4376 the result vector, which element of the two input vectors the result element
4377 gets. The element selector may be undef (meaning "don't care") and the
4378 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4379
4380<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4381<pre>
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,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4383 &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]4384 &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]4385 &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]4386 &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]4387 &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]4388 &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]4389 &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]4390</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4391
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4392</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]4393
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4394</div>
4395
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4396<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4397<h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4398 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4399</h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4400
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4401<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4402
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4403<p>LLVM supports several instructions for working with
4404 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4405
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4406<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4407<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4408 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4409</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4410
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4411<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4412
4413<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4414<pre>
4415 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4416</pre>
4417
4418<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4419<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4420 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4421
4422<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4423<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4424 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4425 <a href="#t_array">array</a> type. The operands are constant indices to
4426 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4427 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4428 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4429 <ul>
4430 <li>Since the value being indexed is not a pointer, the first index is
4431 omitted and assumed to be zero.</li>
4432 <li>At least one index must be specified.</li>
4433 <li>Not only struct indices but also array indices must be in
4434 bounds.</li>
4435 </ul>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4436
4437<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4438<p>The result is the value at the position in the aggregate specified by the
4439 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4440
4441<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4442<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4443 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4444</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4445
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4446</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4447
4448<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4449<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4450 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4451</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4452
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4453<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4454
4455<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4456<pre>
Bill Wendling194229e2011-07-26 20:42:28 +0000[diff] [blame]4457 &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]4458</pre>
4459
4460<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4461<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4462 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4463
4464<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4465<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4466 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4467 <a href="#t_array">array</a> type. The second operand is a first-class
4468 value to insert. The following operands are constant indices indicating
4469 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]4470 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4471 value to insert must have the same type as the value identified by the
4472 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4473
4474<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4475<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4476 that of <tt>val</tt> except that the value at the position specified by the
4477 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4478
4479<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4480<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame]4481 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4482 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4483 %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]4484</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4485
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4486</div>
4487
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4488</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4489
4490<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4491<h3>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4492 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4493</h3>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4494
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4495<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4496
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4497<p>A key design point of an SSA-based representation is how it represents
4498 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4499 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4500 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4501
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4502<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4503<h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4504 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4505</h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4506
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4507<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4508
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4509<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4510<pre>
Dan Gohmanf75a7d32010-05-28 01:14:11 +0000[diff] [blame]4511 &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]4512</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4513
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4514<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4515<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4516 currently executing function, to be automatically released when this function
4517 returns to its caller. The object is always allocated in the generic address
4518 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4519
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4520<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4521<p>The '<tt>alloca</tt>' instruction
4522 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4523 runtime stack, returning a pointer of the appropriate type to the program.
4524 If "NumElements" is specified, it is the number of elements allocated,
4525 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4526 specified, the value result of the allocation is guaranteed to be aligned to
4527 at least that boundary. If not specified, or if zero, the target can choose
4528 to align the allocation on any convenient boundary compatible with the
4529 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4530
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4531<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4532
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4533<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4534<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4535 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4536 memory is automatically released when the function returns. The
4537 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4538 variables that must have an address available. When the function returns
4539 (either with the <tt><a href="#i_ret">ret</a></tt>
4540 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4541 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4542
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4543<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4544<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4545 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4546 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4547 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4548 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4549</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4550
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4551</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4552
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4553<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4554<h4>
4555 <a name="i_load">'<tt>load</tt>' Instruction</a>
4556</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4557
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4558<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4559
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4560<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4561<pre>
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4562 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4563 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4564 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4565</pre>
4566
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4567<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4568<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4569
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4570<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4571<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4572 from which to load. The pointer must point to
4573 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4574 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4575 number or order of execution of this <tt>load</tt> with other <a
4576 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4577
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4578<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4579 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]4580 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4581 alignment for the target. It is the responsibility of the code emitter to
4582 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4583 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4584 produce less efficient code. An alignment of 1 is always safe.</p>
4585
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4586<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4587 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4588 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4589 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4590 and code generator that this load is not expected to be reused in the cache.
4591 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4592 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4593
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4594<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4595<p>The location of memory pointed to is loaded. If the value being loaded is of
4596 scalar type then the number of bytes read does not exceed the minimum number
4597 of bytes needed to hold all bits of the type. For example, loading an
4598 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4599 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4600 is undefined if the value was not originally written using a store of the
4601 same type.</p>
4602
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4603<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4604<pre>
4605 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4606 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4607 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4608</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4609
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4610</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4611
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4612<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4613<h4>
4614 <a name="i_store">'<tt>store</tt>' Instruction</a>
4615</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4616
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4617<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4618
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4619<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4620<pre>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4621 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>
4622 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]4623</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4624
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4625<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4626<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4627
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4628<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4629<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4630 and an address at which to store it. The type of the
4631 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4632 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4633 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4634 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4635 order of execution of this <tt>store</tt> with other <a
4636 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4637
4638<p>The optional constant "align" argument specifies the alignment of the
4639 operation (that is, the alignment of the memory address). A value of 0 or an
4640 omitted "align" argument means that the operation has the preferential
4641 alignment for the target. It is the responsibility of the code emitter to
4642 ensure that the alignment information is correct. Overestimating the
4643 alignment results in an undefined behavior. Underestimating the alignment may
4644 produce less efficient code. An alignment of 1 is always safe.</p>
4645
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4646<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4647 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4648 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4649 instruction tells the optimizer and code generator that this load is
4650 not expected to be reused in the cache. The code generator may
4651 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4652 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4653
4654
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4655<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4656<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4657 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4658 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4659 does not exceed the minimum number of bytes needed to hold all bits of the
4660 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4661 writing a value of a type like <tt>i20</tt> with a size that is not an
4662 integral number of bytes, it is unspecified what happens to the extra bits
4663 that do not belong to the type, but they will typically be overwritten.</p>
4664
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4665<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4666<pre>
4667 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4668 store i32 3, i32* %ptr <i>; yields {void}</i>
4669 %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]4670</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4671
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4672</div>
4673
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4674<!-- _______________________________________________________________________ -->
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame]4675<div class="doc_subsubsection"> <a name="i_fence">'<tt>fence</tt>'
4676Instruction</a> </div>
4677
4678<div class="doc_text">
4679
4680<h5>Syntax:</h5>
4681<pre>
4682 fence [singlethread] &lt;ordering&gt; <i>; yields {void}</i>
4683</pre>
4684
4685<h5>Overview:</h5>
4686<p>The '<tt>fence</tt>' instruction is used to introduce happens-before edges
4687between operations.</p>
4688
4689<h5>Arguments:</h5> <p>'<code>fence</code>' instructions take an <a
4690href="#ordering">ordering</a> argument which defines what
4691<i>synchronizes-with</i> edges they add. They can only be given
4692<code>acquire</code>, <code>release</code>, <code>acq_rel</code>, and
4693<code>seq_cst</code> orderings.</p>
4694
4695<h5>Semantics:</h5>
4696<p>A fence <var>A</var> which has (at least) <code>release</code> ordering
4697semantics <i>synchronizes with</i> a fence <var>B</var> with (at least)
4698<code>acquire</code> ordering semantics if and only if there exist atomic
4699operations <var>X</var> and <var>Y</var>, both operating on some atomic object
4700<var>M</var>, such that <var>A</var> is sequenced before <var>X</var>,
4701<var>X</var> modifies <var>M</var> (either directly or through some side effect
4702of a sequence headed by <var>X</var>), <var>Y</var> is sequenced before
4703<var>B</var>, and <var>Y</var> observes <var>M</var>. This provides a
4704<i>happens-before</i> dependency between <var>A</var> and <var>B</var>. Rather
4705than an explicit <code>fence</code>, one (but not both) of the atomic operations
4706<var>X</var> or <var>Y</var> might provide a <code>release</code> or
4707<code>acquire</code> (resp.) ordering constraint and still
4708<i>synchronize-with</i> the explicit <code>fence</code> and establish the
4709<i>happens-before</i> edge.</p>
4710
4711<p>A <code>fence</code> which has <code>seq_cst</code> ordering, in addition to
4712having both <code>acquire</code> and <code>release</code> semantics specified
4713above, participates in the global program order of other <code>seq_cst</code>
4714operations and/or fences.</p>
4715
4716<p>The optional "<a href="#singlethread"><code>singlethread</code></a>" argument
4717specifies that the fence only synchronizes with other fences in the same
4718thread. (This is useful for interacting with signal handlers.)</p>
4719
4720<p>FIXME: This instruction is a work in progress; until it is finished, use
4721 llvm.memory.barrier.
4722
4723<h5>Example:</h5>
4724<pre>
4725 fence acquire <i>; yields {void}</i>
4726 fence singlethread seq_cst <i>; yields {void}</i>
4727</pre>
4728
4729</div>
4730
4731<!-- _______________________________________________________________________ -->
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4732<div class="doc_subsubsection"> <a name="i_cmpxchg">'<tt>cmpxchg</tt>'
4733Instruction</a> </div>
4734
4735<div class="doc_text">
4736
4737<h5>Syntax:</h5>
4738<pre>
4739 [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>
4740</pre>
4741
4742<h5>Overview:</h5>
4743<p>The '<tt>cmpxchg</tt>' instruction is used to atomically modify memory.
4744It loads a value in memory and compares it to a given value. If they are
4745equal, it stores a new value into the memory.</p>
4746
4747<h5>Arguments:</h5>
4748<p>There are three arguments to the '<code>cmpxchg</code>' instruction: an
4749address to operate on, a value to compare to the value currently be at that
4750address, and a new value to place at that address if the compared values are
4751equal. The type of '<var>&lt;cmp&gt;</var>' must be an integer type whose
4752bit width is a power of two greater than or equal to eight and less than
4753or equal to a target-specific size limit. '<var>&lt;cmp&gt;</var>' and
4754'<var>&lt;new&gt;</var>' must have the same type, and the type of
4755'<var>&lt;pointer&gt;</var>' must be a pointer to that type. If the
4756<code>cmpxchg</code> is marked as <code>volatile</code>, then the
4757optimizer is not allowed to modify the number or order of execution
4758of this <code>cmpxchg</code> with other <a href="#volatile">volatile
4759operations</a>.</p>
4760
4761<!-- FIXME: Extend allowed types. -->
4762
4763<p>The <a href="#ordering"><var>ordering</var></a> argument specifies how this
4764<code>cmpxchg</code> synchronizes with other atomic operations.</p>
4765
4766<p>The optional "<code>singlethread</code>" argument declares that the
4767<code>cmpxchg</code> is only atomic with respect to code (usually signal
4768handlers) running in the same thread as the <code>cmpxchg</code>. Otherwise the
4769cmpxchg is atomic with respect to all other code in the system.</p>
4770
4771<p>The pointer passed into cmpxchg must have alignment greater than or equal to
4772the size in memory of the operand.
4773
4774<h5>Semantics:</h5>
4775<p>The contents of memory at the location specified by the
4776'<tt>&lt;pointer&gt;</tt>' operand is read and compared to
4777'<tt>&lt;cmp&gt;</tt>'; if the read value is the equal,
4778'<tt>&lt;new&gt;</tt>' is written. The original value at the location
4779is returned.
4780
4781<p>A successful <code>cmpxchg</code> is a read-modify-write instruction for the
4782purpose of identifying <a href="#release_sequence">release sequences</a>. A
4783failed <code>cmpxchg</code> is equivalent to an atomic load with an ordering
4784parameter determined by dropping any <code>release</code> part of the
4785<code>cmpxchg</code>'s ordering.</p>
4786
4787<!--
4788FIXME: Is compare_exchange_weak() necessary? (Consider after we've done
4789optimization work on ARM.)
4790
4791FIXME: Is a weaker ordering constraint on failure helpful in practice?
4792-->
4793
4794<h5>Example:</h5>
4795<pre>
4796entry:
4797 %orig = atomic <a href="#i_load">load</a> i32* %ptr unordered <i>; yields {i32}</i>
4798 <a href="#i_br">br</a> label %loop
4799
4800loop:
4801 %cmp = <a href="#i_phi">phi</a> i32 [ %orig, %entry ], [%old, %loop]
4802 %squared = <a href="#i_mul">mul</a> i32 %cmp, %cmp
4803 %old = cmpxchg i32* %ptr, i32 %cmp, i32 %squared <i>; yields {i32}</i>
4804 %success = <a href="#i_icmp">icmp</a> eq i32 %cmp, %old
4805 <a href="#i_br">br</a> i1 %success, label %done, label %loop
4806
4807done:
4808 ...
4809</pre>
4810
4811</div>
4812
4813<!-- _______________________________________________________________________ -->
4814<div class="doc_subsubsection"> <a name="i_atomicrmw">'<tt>atomicrmw</tt>'
4815Instruction</a> </div>
4816
4817<div class="doc_text">
4818
4819<h5>Syntax:</h5>
4820<pre>
4821 [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>
4822</pre>
4823
4824<h5>Overview:</h5>
4825<p>The '<tt>atomicrmw</tt>' instruction is used to atomically modify memory.</p>
4826
4827<h5>Arguments:</h5>
4828<p>There are three arguments to the '<code>atomicrmw</code>' instruction: an
4829operation to apply, an address whose value to modify, an argument to the
4830operation. The operation must be one of the following keywords:</p>
4831<ul>
4832 <li>xchg</li>
4833 <li>add</li>
4834 <li>sub</li>
4835 <li>and</li>
4836 <li>nand</li>
4837 <li>or</li>
4838 <li>xor</li>
4839 <li>max</li>
4840 <li>min</li>
4841 <li>umax</li>
4842 <li>umin</li>
4843</ul>
4844
4845<p>The type of '<var>&lt;value&gt;</var>' must be an integer type whose
4846bit width is a power of two greater than or equal to eight and less than
4847or equal to a target-specific size limit. The type of the
4848'<code>&lt;pointer&gt;</code>' operand must be a pointer to that type.
4849If the <code>atomicrmw</code> is marked as <code>volatile</code>, then the
4850optimizer is not allowed to modify the number or order of execution of this
4851<code>atomicrmw</code> with other <a href="#volatile">volatile
4852 operations</a>.</p>
4853
4854<!-- FIXME: Extend allowed types. -->
4855
4856<h5>Semantics:</h5>
4857<p>The contents of memory at the location specified by the
4858'<tt>&lt;pointer&gt;</tt>' operand are atomically read, modified, and written
4859back. The original value at the location is returned. The modification is
4860specified by the <var>operation</var> argument:</p>
4861
4862<ul>
4863 <li>xchg: <code>*ptr = val</code></li>
4864 <li>add: <code>*ptr = *ptr + val</code></li>
4865 <li>sub: <code>*ptr = *ptr - val</code></li>
4866 <li>and: <code>*ptr = *ptr &amp; val</code></li>
4867 <li>nand: <code>*ptr = ~(*ptr &amp; val)</code></li>
4868 <li>or: <code>*ptr = *ptr | val</code></li>
4869 <li>xor: <code>*ptr = *ptr ^ val</code></li>
4870 <li>max: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using a signed comparison)</li>
4871 <li>min: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using a signed comparison)</li>
4872 <li>umax: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4873 <li>umin: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4874</ul>
4875
4876<h5>Example:</h5>
4877<pre>
4878 %old = atomicrmw add i32* %ptr, i32 1 acquire <i>; yields {i32}</i>
4879</pre>
4880
4881</div>
4882
4883<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4884<h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4885 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4886</h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4887
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4888<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4889
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4890<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4891<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4892 &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]4893 &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]4894</pre>
4895
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4896<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4897<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4898 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4899 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4900
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4901<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4902<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4903 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4904 elements of the aggregate object are indexed. The interpretation of each
4905 index is dependent on the type being indexed into. The first index always
4906 indexes the pointer value given as the first argument, the second index
4907 indexes a value of the type pointed to (not necessarily the value directly
4908 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4909 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4910 vectors, and structs. Note that subsequent types being indexed into
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4911 can never be pointers, since that would require loading the pointer before
4912 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4913
4914<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]4915 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4916 integer <b>constants</b> are allowed. When indexing into an array, pointer
4917 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]4918 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4919
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4920<p>For example, let's consider a C code fragment and how it gets compiled to
4921 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4922
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4923<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4924struct RT {
4925 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4926 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4927 char C;
4928};
4929struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4930 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4931 double Y;
4932 struct RT Z;
4933};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4934
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4935int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4936 return &amp;s[1].Z.B[5][13];
4937}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4938</pre>
4939
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4940<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4941
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4942<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]4943%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4944%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4945
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4946define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4947entry:
4948 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4949 ret i32* %reg
4950}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4951</pre>
4952
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4953<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4954<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]4955 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4956 }</tt>' type, a structure. The second index indexes into the third element
4957 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4958 i8 }</tt>' type, another structure. The third index indexes into the second
4959 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4960 array. The two dimensions of the array are subscripted into, yielding an
4961 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4962 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4963
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4964<p>Note that it is perfectly legal to index partially through a structure,
4965 returning a pointer to an inner element. Because of this, the LLVM code for
4966 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4967
4968<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4969 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4970 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4971 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4972 %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]4973 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4974 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4975 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4976 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4977</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]4978
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4979<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]4980 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4981 base pointer is not an <i>in bounds</i> address of an allocated object,
4982 or if any of the addresses that would be formed by successive addition of
4983 the offsets implied by the indices to the base address with infinitely
4984 precise arithmetic are not an <i>in bounds</i> address of that allocated
4985 object. The <i>in bounds</i> addresses for an allocated object are all
4986 the addresses that point into the object, plus the address one byte past
4987 the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4988
4989<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4990 the base address with silently-wrapping two's complement arithmetic, and
4991 the result value of the <tt>getelementptr</tt> may be outside the object
4992 pointed to by the base pointer. The result value may not necessarily be
4993 used to access memory though, even if it happens to point into allocated
4994 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4995 section for more information.</p>
4996
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4997<p>The getelementptr instruction is often confusing. For some more insight into
4998 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4999
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]5000<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5001<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5002 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]5003 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
5004 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5005 %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]5006 <i>; yields i8*:eptr</i>
5007 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]5008 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]5009 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5010</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5011
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]5012</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]5013
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5014</div>
5015
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5016<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5017<h3>
5018 <a name="convertops">Conversion Operations</a>
5019</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5020
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5021<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5022
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5023<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5024 which all take a single operand and a type. They perform various bit
5025 conversions on the operand.</p>
5026
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5027<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5028<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5029 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5030</h4>
5031
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5032<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5033
5034<h5>Syntax:</h5>
5035<pre>
5036 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5037</pre>
5038
5039<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5040<p>The '<tt>trunc</tt>' instruction truncates its operand to the
5041 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5042
5043<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5044<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
5045 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5046 of the same number of integers.
5047 The bit size of the <tt>value</tt> must be larger than
5048 the bit size of the destination type, <tt>ty2</tt>.
5049 Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5050
5051<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5052<p>The '<tt>trunc</tt>' instruction truncates the high order bits
5053 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
5054 source size must be larger than the destination size, <tt>trunc</tt> cannot
5055 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5056
5057<h5>Example:</h5>
5058<pre>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5059 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
5060 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
5061 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
5062 %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]5063</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5064
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5065</div>
5066
5067<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5068<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5069 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5070</h4>
5071
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5072<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5073
5074<h5>Syntax:</h5>
5075<pre>
5076 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5077</pre>
5078
5079<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5080<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5081 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5082
5083
5084<h5>Arguments:</h5>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]5085<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
5086 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5087 of the same number of integers.
5088 The bit size of the <tt>value</tt> must be smaller than
5089 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5090 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5091
5092<h5>Semantics:</h5>
5093<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]5094 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5095
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]5096<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]5097
5098<h5>Example:</h5>
5099<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5100 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5101 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]5102 %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]5103</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5104
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5105</div>
5106
5107<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5108<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5109 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5110</h4>
5111
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5112<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5113
5114<h5>Syntax:</h5>
5115<pre>
5116 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5117</pre>
5118
5119<h5>Overview:</h5>
5120<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
5121
5122<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5123<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
5124 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5125 of the same number of integers.
5126 The bit size of the <tt>value</tt> must be smaller than
5127 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5128 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5129
5130<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5131<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
5132 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
5133 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5134
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5135<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]5136
5137<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5138<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5139 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5140 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5141 %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]5142</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5143
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5144</div>
5145
5146<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5147<h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5148 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5149</h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5150
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5151<div>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5152
5153<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5154<pre>
5155 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5156</pre>
5157
5158<h5>Overview:</h5>
5159<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5160 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5161
5162<h5>Arguments:</h5>
5163<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5164 point</a> value to cast and a <a href="#t_floating">floating point</a> type
5165 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]5166 <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]5167 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5168
5169<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5170<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5171 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5172 <a href="#t_floating">floating point</a> type. If the value cannot fit
5173 within the destination type, <tt>ty2</tt>, then the results are
5174 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5175
5176<h5>Example:</h5>
5177<pre>
5178 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
5179 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
5180</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5181
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5182</div>
5183
5184<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5185<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5186 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5187</h4>
5188
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5189<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5190
5191<h5>Syntax:</h5>
5192<pre>
5193 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5194</pre>
5195
5196<h5>Overview:</h5>
5197<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]5198 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5199
5200<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5201<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5202 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
5203 a <a href="#t_floating">floating point</a> type to cast it to. The source
5204 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5205
5206<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5207<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5208 <a href="#t_floating">floating point</a> type to a larger
5209 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
5210 used to make a <i>no-op cast</i> because it always changes bits. Use
5211 <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]5212
5213<h5>Example:</h5>
5214<pre>
Nick Lewycky5bb3ece2011-03-31 18:20:19 +0000[diff] [blame]5215 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
5216 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5217</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5218
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5219</div>
5220
5221<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5222<h4>
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]5223 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5224</h4>
5225
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5226<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5227
5228<h5>Syntax:</h5>
5229<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5230 &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]5231</pre>
5232
5233<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5234<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5235 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5236
5237<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5238<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
5239 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5240 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5241 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5242 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5243
5244<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5245<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5246 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5247 towards zero) unsigned integer value. If the value cannot fit
5248 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5249
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5250<h5>Example:</h5>
5251<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5252 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]5253 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5254 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5255</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5256
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5257</div>
5258
5259<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5260<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5261 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5262</h4>
5263
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5264<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5265
5266<h5>Syntax:</h5>
5267<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5268 &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]5269</pre>
5270
5271<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5272<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5273 <a href="#t_floating">floating point</a> <tt>value</tt> to
5274 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5275
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5276<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5277<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
5278 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5279 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5280 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5281 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5282
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5283<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5284<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5285 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5286 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
5287 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5288
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]5289<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5290<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5291 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]5292 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5293 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5294</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5295
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5296</div>
5297
5298<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5299<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5300 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5301</h4>
5302
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5303<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5304
5305<h5>Syntax:</h5>
5306<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5307 &lt;result&gt; = 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]5308</pre>
5309
5310<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5311<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5312 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5313
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5314<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5315<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]5316 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5317 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5318 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5319 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5320
5321<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5322<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5323 integer quantity and converts it to the corresponding floating point
5324 value. If the value cannot fit in the floating point value, the results are
5325 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5326
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5327<h5>Example:</h5>
5328<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5329 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5330 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5331</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5332
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5333</div>
5334
5335<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5336<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5337 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5338</h4>
5339
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5340<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5341
5342<h5>Syntax:</h5>
5343<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5344 &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]5345</pre>
5346
5347<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5348<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5349 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5350
5351<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5352<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]5353 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5354 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5355 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5356 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5357
5358<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5359<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5360 quantity and converts it to the corresponding floating point value. If the
5361 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5362
5363<h5>Example:</h5>
5364<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5365 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5366 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5367</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5368
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5369</div>
5370
5371<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5372<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5373 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5374</h4>
5375
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5376<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5377
5378<h5>Syntax:</h5>
5379<pre>
5380 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5381</pre>
5382
5383<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5384<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5385 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5386
5387<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5388<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5389 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5390 <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]5391
5392<h5>Semantics:</h5>
5393<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5394 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5395 truncating or zero extending that value to the size of the integer type. If
5396 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5397 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5398 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5399 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5400
5401<h5>Example:</h5>
5402<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5403 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5404 %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]5405</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5406
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5407</div>
5408
5409<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5410<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5411 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5412</h4>
5413
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5414<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5415
5416<h5>Syntax:</h5>
5417<pre>
5418 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5419</pre>
5420
5421<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5422<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5423 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5424
5425<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]5426<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5427 value to cast, and a type to cast it to, which must be a
5428 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5429
5430<h5>Semantics:</h5>
5431<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5432 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5433 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5434 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5435 than the size of a pointer then a zero extension is done. If they are the
5436 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5437
5438<h5>Example:</h5>
5439<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5440 %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]5441 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5442 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5443</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5444
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5445</div>
5446
5447<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5448<h4>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5449 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5450</h4>
5451
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5452<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5453
5454<h5>Syntax:</h5>
5455<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5456 &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]5457</pre>
5458
5459<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5460<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5461 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5462
5463<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5464<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5465 non-aggregate first class value, and a type to cast it to, which must also be
5466 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5467 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5468 identical. If the source type is a pointer, the destination type must also be
5469 a pointer. This instruction supports bitwise conversion of vectors to
5470 integers and to vectors of other types (as long as they have the same
5471 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5472
5473<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5474<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5475 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5476 this conversion. The conversion is done as if the <tt>value</tt> had been
5477 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5478 be converted to other pointer types with this instruction. To convert
5479 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5480 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5481
5482<h5>Example:</h5>
5483<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5484 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5485 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5486 %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]5487</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5488
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5489</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5490
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5491</div>
5492
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5493<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5494<h3>
5495 <a name="otherops">Other Operations</a>
5496</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5497
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5498<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5499
5500<p>The instructions in this category are the "miscellaneous" instructions, which
5501 defy better classification.</p>
5502
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5503<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5504<h4>
5505 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5506</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5507
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5508<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5509
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5510<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5511<pre>
5512 &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]5513</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5514
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5515<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5516<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5517 boolean values based on comparison of its two integer, integer vector, or
5518 pointer operands.</p>
5519
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5520<h5>Arguments:</h5>
5521<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5522 the condition code indicating the kind of comparison to perform. It is not a
5523 value, just a keyword. The possible condition code are:</p>
5524
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5525<ol>
5526 <li><tt>eq</tt>: equal</li>
5527 <li><tt>ne</tt>: not equal </li>
5528 <li><tt>ugt</tt>: unsigned greater than</li>
5529 <li><tt>uge</tt>: unsigned greater or equal</li>
5530 <li><tt>ult</tt>: unsigned less than</li>
5531 <li><tt>ule</tt>: unsigned less or equal</li>
5532 <li><tt>sgt</tt>: signed greater than</li>
5533 <li><tt>sge</tt>: signed greater or equal</li>
5534 <li><tt>slt</tt>: signed less than</li>
5535 <li><tt>sle</tt>: signed less or equal</li>
5536</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5537
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]5538<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5539 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5540 typed. They must also be identical types.</p>
5541
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5542<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5543<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5544 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5545 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]5546 result, as follows:</p>
5547
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5548<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5549 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5550 <tt>false</tt> otherwise. No sign interpretation is necessary or
5551 performed.</li>
5552
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5553 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5554 <tt>false</tt> otherwise. No sign interpretation is necessary or
5555 performed.</li>
5556
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5557 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5558 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5559
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5560 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5561 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5562 to <tt>op2</tt>.</li>
5563
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5564 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5565 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5566
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5567 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5568 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5569
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5570 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5571 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5572
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5573 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5574 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5575 to <tt>op2</tt>.</li>
5576
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5577 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5578 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5579
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5580 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5581 <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]5582</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5583
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5584<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5585 values are compared as if they were integers.</p>
5586
5587<p>If the operands are integer vectors, then they are compared element by
5588 element. The result is an <tt>i1</tt> vector with the same number of elements
5589 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5590
5591<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5592<pre>
5593 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5594 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5595 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5596 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5597 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5598 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5599</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5600
5601<p>Note that the code generator does not yet support vector types with
5602 the <tt>icmp</tt> instruction.</p>
5603
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5604</div>
5605
5606<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5607<h4>
5608 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5609</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5610
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5611<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5612
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5613<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5614<pre>
5615 &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]5616</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5617
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5618<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5619<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5620 values based on comparison of its operands.</p>
5621
5622<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]5623(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5624
5625<p>If the operands are floating point vectors, then the result type is a vector
5626 of boolean with the same number of elements as the operands being
5627 compared.</p>
5628
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5629<h5>Arguments:</h5>
5630<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5631 the condition code indicating the kind of comparison to perform. It is not a
5632 value, just a keyword. The possible condition code are:</p>
5633
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5634<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5635 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5636 <li><tt>oeq</tt>: ordered and equal</li>
5637 <li><tt>ogt</tt>: ordered and greater than </li>
5638 <li><tt>oge</tt>: ordered and greater than or equal</li>
5639 <li><tt>olt</tt>: ordered and less than </li>
5640 <li><tt>ole</tt>: ordered and less than or equal</li>
5641 <li><tt>one</tt>: ordered and not equal</li>
5642 <li><tt>ord</tt>: ordered (no nans)</li>
5643 <li><tt>ueq</tt>: unordered or equal</li>
5644 <li><tt>ugt</tt>: unordered or greater than </li>
5645 <li><tt>uge</tt>: unordered or greater than or equal</li>
5646 <li><tt>ult</tt>: unordered or less than </li>
5647 <li><tt>ule</tt>: unordered or less than or equal</li>
5648 <li><tt>une</tt>: unordered or not equal</li>
5649 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5650 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5651</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5652
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5653<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5654 <i>unordered</i> means that either operand may be a QNAN.</p>
5655
5656<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5657 a <a href="#t_floating">floating point</a> type or
5658 a <a href="#t_vector">vector</a> of floating point type. They must have
5659 identical types.</p>
5660
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5661<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]5662<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5663 according to the condition code given as <tt>cond</tt>. If the operands are
5664 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5665 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5666 follows:</p>
5667
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5668<ol>
5669 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</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>oeq</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 equal to <tt>op2</tt>.</li>
5673
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5674 <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]5675 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5676
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5677 <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]5678 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5679
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5680 <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]5681 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5682
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5683 <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]5684 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5685
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5686 <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]5687 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5688
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5689 <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]5690
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5691 <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]5692 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5693
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5694 <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]5695 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5696
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5697 <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]5698 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5699
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5700 <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]5701 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5702
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5703 <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]5704 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5705
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5706 <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]5707 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5708
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5709 <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]5710
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5711 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5712</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5713
5714<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5715<pre>
5716 &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]5717 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5718 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5719 &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]5720</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5721
5722<p>Note that the code generator does not yet support vector types with
5723 the <tt>fcmp</tt> instruction.</p>
5724
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5725</div>
5726
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5727<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5728<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5729 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5730</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5731
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5732<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5733
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5734<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5735<pre>
5736 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5737</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5738
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5739<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5740<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5741 SSA graph representing the function.</p>
5742
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5743<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5744<p>The type of the incoming values is specified with the first type field. After
5745 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5746 one pair for each predecessor basic block of the current block. Only values
5747 of <a href="#t_firstclass">first class</a> type may be used as the value
5748 arguments to the PHI node. Only labels may be used as the label
5749 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5750
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5751<p>There must be no non-phi instructions between the start of a basic block and
5752 the PHI instructions: i.e. PHI instructions must be first in a basic
5753 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5754
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5755<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5756 occur on the edge from the corresponding predecessor block to the current
5757 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5758 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]5759
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5760<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5761<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5762 specified by the pair corresponding to the predecessor basic block that
5763 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5764
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5765<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5766<pre>
5767Loop: ; Infinite loop that counts from 0 on up...
5768 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5769 %nextindvar = add i32 %indvar, 1
5770 br label %Loop
5771</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5772
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5773</div>
5774
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5775<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5776<h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5777 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5778</h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5779
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5780<div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5781
5782<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5783<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5784 &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>
5785
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5786 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5787</pre>
5788
5789<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5790<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5791 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5792
5793
5794<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5795<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5796 values indicating the condition, and two values of the
5797 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5798 vectors and the condition is a scalar, then entire vectors are selected, not
5799 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5800
5801<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5802<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5803 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5804
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5805<p>If the condition is a vector of i1, then the value arguments must be vectors
5806 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5807
5808<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5809<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5810 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5811</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5812
5813<p>Note that the code generator does not yet support conditions
5814 with vector type.</p>
5815
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5816</div>
5817
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5818<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5819<h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5820 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5821</h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5822
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5823<div>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5824
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5825<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5826<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]5827 &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]5828</pre>
5829
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5830<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5831<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5832
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5833<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5834<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5835
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5836<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5837 <li>The optional "tail" marker indicates that the callee function does not
5838 access any allocas or varargs in the caller. Note that calls may be
5839 marked "tail" even if they do not occur before
5840 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5841 present, the function call is eligible for tail call optimization,
5842 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Chengdc444e92010-03-08 21:05:02 +0000[diff] [blame]5843 optimized into a jump</a>. The code generator may optimize calls marked
5844 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5845 sibling call optimization</a> when the caller and callee have
5846 matching signatures, or 2) forced tail call optimization when the
5847 following extra requirements are met:
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5848 <ul>
5849 <li>Caller and callee both have the calling
5850 convention <tt>fastcc</tt>.</li>
5851 <li>The call is in tail position (ret immediately follows call and ret
5852 uses value of call or is void).</li>
5853 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohmanfbbee8d2010-03-02 01:08:11 +0000[diff] [blame]5854 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5855 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5856 constraints are met.</a></li>
5857 </ul>
5858 </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 "cconv" marker indicates which <a href="#callingconv">calling
5861 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5862 defaults to using C calling conventions. The calling convention of the
5863 call must match the calling convention of the target function, or else the
5864 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5865
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5866 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5867 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5868 '<tt>inreg</tt>' attributes are valid here.</li>
5869
5870 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5871 type of the return value. Functions that return no value are marked
5872 <tt><a href="#t_void">void</a></tt>.</li>
5873
5874 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5875 being invoked. The argument types must match the types implied by this
5876 signature. This type can be omitted if the function is not varargs and if
5877 the function type does not return a pointer to a function.</li>
5878
5879 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5880 be invoked. In most cases, this is a direct function invocation, but
5881 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5882 to function value.</li>
5883
5884 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]5885 signature argument types and parameter attributes. All arguments must be
5886 of <a href="#t_firstclass">first class</a> type. If the function
5887 signature indicates the function accepts a variable number of arguments,
5888 the extra arguments can be specified.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5889
5890 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5891 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5892 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5893</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5894
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5895<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5896<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5897 a specified function, with its incoming arguments bound to the specified
5898 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5899 function, control flow continues with the instruction after the function
5900 call, and the return value of the function is bound to the result
5901 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5902
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5903<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5904<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]5905 %retval = call i32 @test(i32 %argc)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]5906 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]5907 %X = tail call i32 @foo() <i>; yields i32</i>
5908 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5909 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]5910
5911 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5912 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]5913 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5914 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]5915 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]5916 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5917</pre>
5918
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5919<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]5920standard C99 library as being the C99 library functions, and may perform
5921optimizations or generate code for them under that assumption. This is
5922something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5923freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5924
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5925</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5926
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5927<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5928<h4>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]5929 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5930</h4>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5931
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5932<div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5933
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5934<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5935<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5936 &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]5937</pre>
5938
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5939<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5940<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5941 the "variable argument" area of a function call. It is used to implement the
5942 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5943
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5944<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5945<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5946 argument. It returns a value of the specified argument type and increments
5947 the <tt>va_list</tt> to point to the next argument. The actual type
5948 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5949
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5950<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5951<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5952 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5953 to the next argument. For more information, see the variable argument
5954 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5955
5956<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]5957 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5958 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5959
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5960<p><tt>va_arg</tt> is an LLVM instruction instead of
5961 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5962 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5963
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5964<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5965<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5966
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5967<p>Note that the code generator does not yet fully support va_arg on many
5968 targets. Also, it does not currently support va_arg with aggregate types on
5969 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]5970
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5971</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5972
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5973</div>
5974
5975</div>
5976
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5977<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5978<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]5979<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5980
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5981<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5982
5983<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5984 well known names and semantics and are required to follow certain
5985 restrictions. Overall, these intrinsics represent an extension mechanism for
5986 the LLVM language that does not require changing all of the transformations
5987 in LLVM when adding to the language (or the bitcode reader/writer, the
5988 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5989
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5990<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5991 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5992 begin with this prefix. Intrinsic functions must always be external
5993 functions: you cannot define the body of intrinsic functions. Intrinsic
5994 functions may only be used in call or invoke instructions: it is illegal to
5995 take the address of an intrinsic function. Additionally, because intrinsic
5996 functions are part of the LLVM language, it is required if any are added that
5997 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5998
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5999<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
6000 family of functions that perform the same operation but on different data
6001 types. Because LLVM can represent over 8 million different integer types,
6002 overloading is used commonly to allow an intrinsic function to operate on any
6003 integer type. One or more of the argument types or the result type can be
6004 overloaded to accept any integer type. Argument types may also be defined as
6005 exactly matching a previous argument's type or the result type. This allows
6006 an intrinsic function which accepts multiple arguments, but needs all of them
6007 to be of the same type, to only be overloaded with respect to a single
6008 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6009
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6010<p>Overloaded intrinsics will have the names of its overloaded argument types
6011 encoded into its function name, each preceded by a period. Only those types
6012 which are overloaded result in a name suffix. Arguments whose type is matched
6013 against another type do not. For example, the <tt>llvm.ctpop</tt> function
6014 can take an integer of any width and returns an integer of exactly the same
6015 integer width. This leads to a family of functions such as
6016 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
6017 %val)</tt>. Only one type, the return type, is overloaded, and only one type
6018 suffix is required. Because the argument's type is matched against the return
6019 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6020
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6021<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6022 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6023
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6024<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6025<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6026 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6027</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6028
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6029<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6030
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6031<p>Variable argument support is defined in LLVM with
6032 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
6033 intrinsic functions. These functions are related to the similarly named
6034 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6035
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6036<p>All of these functions operate on arguments that use a target-specific value
6037 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
6038 not define what this type is, so all transformations should be prepared to
6039 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6040
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]6041<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]6042 instruction and the variable argument handling intrinsic functions are
6043 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6044
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]6045<pre class="doc_code">
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6046define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6047 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6048 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6049 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6050 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6051
6052 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6053 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6054
6055 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6056 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6057 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6058 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6059 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6060
6061 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6062 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]6063 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6064}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6065
6066declare void @llvm.va_start(i8*)
6067declare void @llvm.va_copy(i8*, i8*)
6068declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6069</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6070
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6071<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6072<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6073 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6074</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6075
6076
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6077<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6078
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6079<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6080<pre>
6081 declare void %llvm.va_start(i8* &lt;arglist&gt;)
6082</pre>
6083
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6084<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6085<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
6086 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]6087
6088<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6089<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]6090
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6091<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6092<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]6093 macro available in C. In a target-dependent way, it initializes
6094 the <tt>va_list</tt> element to which the argument points, so that the next
6095 call to <tt>va_arg</tt> will produce the first variable argument passed to
6096 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
6097 need to know the last argument of the function as the compiler can figure
6098 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6099
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6100</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6101
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6102<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6103<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6104 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6105</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6106
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6107<div>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6108
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6109<h5>Syntax:</h5>
6110<pre>
6111 declare void @llvm.va_end(i8* &lt;arglist&gt;)
6112</pre>
6113
6114<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6115<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6116 which has been initialized previously
6117 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
6118 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6119
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6120<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6121<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]6122
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6123<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6124<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]6125 macro available in C. In a target-dependent way, it destroys
6126 the <tt>va_list</tt> element to which the argument points. Calls
6127 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
6128 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
6129 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6130
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6131</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6132
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6133<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6134<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6135 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6136</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6137
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6138<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6139
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6140<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6141<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6142 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6143</pre>
6144
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6145<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6146<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6147 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6148
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6149<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6150<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]6151 The second argument is a pointer to a <tt>va_list</tt> element to copy
6152 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6153
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6154<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6155<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]6156 macro available in C. In a target-dependent way, it copies the
6157 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
6158 element. This intrinsic is necessary because
6159 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
6160 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6161
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6162</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6163
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6164</div>
6165
Bill Wendling0246bb72011-07-31 06:45:03 +0000[diff] [blame]6166</div>
6167
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6168<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6169<h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6170 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6171</h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6172
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6173<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6174
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6175<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]6176Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6177intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
6178roots on the stack</a>, as well as garbage collector implementations that
6179require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
6180barriers. Front-ends for type-safe garbage collected languages should generate
6181these intrinsics to make use of the LLVM garbage collectors. For more details,
6182see <a href="GarbageCollection.html">Accurate Garbage Collection with
6183LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]6184
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6185<p>The garbage collection intrinsics only operate on objects in the generic
6186 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]6187
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6188<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6189<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6190 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6191</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6192
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6193<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6194
6195<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6196<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6197 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6198</pre>
6199
6200<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]6201<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]6202 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6203
6204<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6205<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6206 root pointer. The second pointer (which must be either a constant or a
6207 global value address) contains the meta-data to be associated with the
6208 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6209
6210<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]6211<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]6212 location. At compile-time, the code generator generates information to allow
6213 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
6214 intrinsic may only be used in a function which <a href="#gc">specifies a GC
6215 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6216
6217</div>
6218
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6219<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6220<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6221 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6222</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6223
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6224<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6225
6226<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6227<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6228 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6229</pre>
6230
6231<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6232<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6233 locations, allowing garbage collector implementations that require read
6234 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6235
6236<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]6237<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]6238 allocated from the garbage collector. The first object is a pointer to the
6239 start of the referenced object, if needed by the language runtime (otherwise
6240 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6241
6242<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6243<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6244 instruction, but may be replaced with substantially more complex code by the
6245 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
6246 may only be used in a function which <a href="#gc">specifies a GC
6247 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6248
6249</div>
6250
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6251<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6252<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6253 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6254</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6255
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6256<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6257
6258<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6259<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6260 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6261</pre>
6262
6263<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6264<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6265 locations, allowing garbage collector implementations that require write
6266 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6267
6268<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]6269<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]6270 object to store it to, and the third is the address of the field of Obj to
6271 store to. If the runtime does not require a pointer to the object, Obj may
6272 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6273
6274<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6275<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6276 instruction, but may be replaced with substantially more complex code by the
6277 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
6278 may only be used in a function which <a href="#gc">specifies a GC
6279 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6280
6281</div>
6282
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6283</div>
6284
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6285<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6286<h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6287 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6288</h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6289
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6290<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6291
6292<p>These intrinsics are provided by LLVM to expose special features that may
6293 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6294
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6295<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6296<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6297 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6298</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6299
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6300<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6301
6302<h5>Syntax:</h5>
6303<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6304 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6305</pre>
6306
6307<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6308<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
6309 target-specific value indicating the return address of the current function
6310 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6311
6312<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6313<p>The argument to this intrinsic indicates which function to return the address
6314 for. Zero indicates the calling function, one indicates its caller, etc.
6315 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6316
6317<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6318<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
6319 indicating the return address of the specified call frame, or zero if it
6320 cannot be identified. The value returned by this intrinsic is likely to be
6321 incorrect or 0 for arguments other than zero, so it should only be used for
6322 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6323
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6324<p>Note that calling this intrinsic does not prevent function inlining or other
6325 aggressive transformations, so the value returned may not be that of the
6326 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6327
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6328</div>
6329
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6330<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6331<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6332 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6333</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6334
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6335<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6336
6337<h5>Syntax:</h5>
6338<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6339 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6340</pre>
6341
6342<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6343<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6344 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6345
6346<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6347<p>The argument to this intrinsic indicates which function to return the frame
6348 pointer for. Zero indicates the calling function, one indicates its caller,
6349 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6350
6351<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6352<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6353 indicating the frame address of the specified call frame, or zero if it
6354 cannot be identified. The value returned by this intrinsic is likely to be
6355 incorrect or 0 for arguments other than zero, so it should only be used for
6356 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6357
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6358<p>Note that calling this intrinsic does not prevent function inlining or other
6359 aggressive transformations, so the value returned may not be that of the
6360 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6361
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6362</div>
6363
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6364<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6365<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6366 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6367</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6368
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6369<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6370
6371<h5>Syntax:</h5>
6372<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6373 declare i8* @llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6374</pre>
6375
6376<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6377<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6378 of the function stack, for use
6379 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6380 useful for implementing language features like scoped automatic variable
6381 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6382
6383<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6384<p>This intrinsic returns a opaque pointer value that can be passed
6385 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6386 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6387 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6388 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6389 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6390 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6391
6392</div>
6393
6394<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6395<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6396 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6397</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6398
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6399<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6400
6401<h5>Syntax:</h5>
6402<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6403 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6404</pre>
6405
6406<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6407<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6408 the function stack to the state it was in when the
6409 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6410 executed. This is useful for implementing language features like scoped
6411 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6412
6413<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6414<p>See the description
6415 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6416
6417</div>
6418
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6419<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6420<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6421 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6422</h4>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6423
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6424<div>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6425
6426<h5>Syntax:</h5>
6427<pre>
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6428 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]6429</pre>
6430
6431<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6432<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6433 insert a prefetch instruction if supported; otherwise, it is a noop.
6434 Prefetches have no effect on the behavior of the program but can change its
6435 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6436
6437<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6438<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6439 specifier determining if the fetch should be for a read (0) or write (1),
6440 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6441 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6442 specifies whether the prefetch is performed on the data (1) or instruction (0)
6443 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6444 must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6445
6446<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6447<p>This intrinsic does not modify the behavior of the program. In particular,
6448 prefetches cannot trap and do not produce a value. On targets that support
6449 this intrinsic, the prefetch can provide hints to the processor cache for
6450 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6451
6452</div>
6453
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6454<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6455<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6456 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6457</h4>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6458
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6459<div>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6460
6461<h5>Syntax:</h5>
6462<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6463 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6464</pre>
6465
6466<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6467<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6468 Counter (PC) in a region of code to simulators and other tools. The method
6469 is target specific, but it is expected that the marker will use exported
6470 symbols to transmit the PC of the marker. The marker makes no guarantees
6471 that it will remain with any specific instruction after optimizations. It is
6472 possible that the presence of a marker will inhibit optimizations. The
6473 intended use is to be inserted after optimizations to allow correlations of
6474 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6475
6476<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6477<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6478
6479<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6480<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6481 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6482
6483</div>
6484
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6485<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6486<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6487 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6488</h4>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6489
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6490<div>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6491
6492<h5>Syntax:</h5>
6493<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]6494 declare i64 @llvm.readcyclecounter()
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6495</pre>
6496
6497<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6498<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6499 counter register (or similar low latency, high accuracy clocks) on those
6500 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6501 should map to RPCC. As the backing counters overflow quickly (on the order
6502 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6503
6504<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6505<p>When directly supported, reading the cycle counter should not modify any
6506 memory. Implementations are allowed to either return a application specific
6507 value or a system wide value. On backends without support, this is lowered
6508 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6509
6510</div>
6511
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6512</div>
6513
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6514<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6515<h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6516 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6517</h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6518
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6519<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6520
6521<p>LLVM provides intrinsics for a few important standard C library functions.
6522 These intrinsics allow source-language front-ends to pass information about
6523 the alignment of the pointer arguments to the code generator, providing
6524 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6525
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6526<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6527<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6528 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6529</h4>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6530
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6531<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6532
6533<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6534<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]6535 integer bit width and for different address spaces. Not all targets support
6536 all bit widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6537
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6538<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6539 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]6540 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6541 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]6542 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6543</pre>
6544
6545<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6546<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6547 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6548
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6549<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6550 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6551 and the pointers can be in specified address spaces.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6552
6553<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6554
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6555<p>The first argument is a pointer to the destination, the second is a pointer
6556 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6557 number of bytes to copy, the fourth argument is the alignment of the
6558 source and destination locations, and the fifth is a boolean indicating a
6559 volatile access.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6560
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6561<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]6562 then the caller guarantees that both the source and destination pointers are
6563 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6564
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6565<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6566 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6567 The detailed access behavior is not very cleanly specified and it is unwise
6568 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6569
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6570<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6571
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6572<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6573 source location to the destination location, which are not allowed to
6574 overlap. It copies "len" bytes of memory over. If the argument is known to
6575 be aligned to some boundary, this can be specified as the fourth argument,
6576 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6577
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6578</div>
6579
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6580<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6581<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6582 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6583</h4>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6584
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6585<div>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6586
6587<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6588<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]6589 width and for different address space. Not all targets support all bit
6590 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6591
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6592<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6593 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]6594 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6595 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]6596 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6597</pre>
6598
6599<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6600<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6601 source location to the destination location. It is similar to the
6602 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6603 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6604
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6605<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6606 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6607 and the pointers can be in specified address spaces.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6608
6609<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6610
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6611<p>The first argument is a pointer to the destination, the second is a pointer
6612 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6613 number of bytes to copy, the fourth argument is the alignment of the
6614 source and destination locations, and the fifth is a boolean indicating a
6615 volatile access.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6616
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6617<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]6618 then the caller guarantees that the source and destination pointers are
6619 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6620
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6621<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6622 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6623 The detailed access behavior is not very cleanly specified and it is unwise
6624 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6625
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6626<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6627
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6628<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6629 source location to the destination location, which may overlap. It copies
6630 "len" bytes of memory over. If the argument is known to be aligned to some
6631 boundary, this can be specified as the fourth argument, otherwise it should
6632 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6633
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6634</div>
6635
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6636<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6637<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6638 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6639</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6640
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6641<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6642
6643<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6644<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]6645 width and for different address spaces. However, not all targets support all
6646 bit widths.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6647
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6648<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6649 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6650 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6651 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6652 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6653</pre>
6654
6655<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6656<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6657 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6658
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6659<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6660 intrinsic does not return a value and takes extra alignment/volatile
6661 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6662
6663<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6664<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]6665 byte value with which to fill it, the third argument is an integer argument
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6666 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6667 alignment of the destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6668
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6669<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]6670 then the caller guarantees that the destination pointer is aligned to that
6671 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6672
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6673<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6674 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6675 The detailed access behavior is not very cleanly specified and it is unwise
6676 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6677
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6678<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6679<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6680 at the destination location. If the argument is known to be aligned to some
6681 boundary, this can be specified as the fourth argument, otherwise it should
6682 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6683
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6684</div>
6685
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6686<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6687<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6688 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6689</h4>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6690
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6691<div>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6692
6693<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6694<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6695 floating point or vector of floating point type. Not all targets support all
6696 types however.</p>
6697
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6698<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6699 declare float @llvm.sqrt.f32(float %Val)
6700 declare double @llvm.sqrt.f64(double %Val)
6701 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6702 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6703 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6704</pre>
6705
6706<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6707<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6708 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6709 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6710 behavior for negative numbers other than -0.0 (which allows for better
6711 optimization, because there is no need to worry about errno being
6712 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]6713
6714<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6715<p>The argument and return value are floating point numbers of the same
6716 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6717
6718<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6719<p>This function returns the sqrt of the specified operand if it is a
6720 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6721
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6722</div>
6723
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6724<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6725<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6726 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6727</h4>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6728
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6729<div>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6730
6731<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6732<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6733 floating point or vector of floating point type. Not all targets support all
6734 types however.</p>
6735
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6736<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6737 declare float @llvm.powi.f32(float %Val, i32 %power)
6738 declare double @llvm.powi.f64(double %Val, i32 %power)
6739 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6740 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6741 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6742</pre>
6743
6744<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6745<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6746 specified (positive or negative) power. The order of evaluation of
6747 multiplications is not defined. When a vector of floating point type is
6748 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6749
6750<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6751<p>The second argument is an integer power, and the first is a value to raise to
6752 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6753
6754<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6755<p>This function returns the first value raised to the second power with an
6756 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6757
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6758</div>
6759
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6760<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6761<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6762 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6763</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6764
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6765<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6766
6767<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6768<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6769 floating point or vector of floating point type. Not all targets support all
6770 types however.</p>
6771
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6772<pre>
6773 declare float @llvm.sin.f32(float %Val)
6774 declare double @llvm.sin.f64(double %Val)
6775 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6776 declare fp128 @llvm.sin.f128(fp128 %Val)
6777 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6778</pre>
6779
6780<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6781<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6782
6783<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6784<p>The argument and return value are floating point numbers of the same
6785 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6786
6787<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6788<p>This function returns the sine of the specified operand, returning the same
6789 values as the libm <tt>sin</tt> functions would, and handles error conditions
6790 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6791
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6792</div>
6793
6794<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6795<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6796 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6797</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6798
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6799<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6800
6801<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6802<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6803 floating point or vector of floating point type. Not all targets support all
6804 types however.</p>
6805
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6806<pre>
6807 declare float @llvm.cos.f32(float %Val)
6808 declare double @llvm.cos.f64(double %Val)
6809 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6810 declare fp128 @llvm.cos.f128(fp128 %Val)
6811 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6812</pre>
6813
6814<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6815<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6816
6817<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6818<p>The argument and return value are floating point numbers of the same
6819 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6820
6821<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6822<p>This function returns the cosine of the specified operand, returning the same
6823 values as the libm <tt>cos</tt> functions would, and handles error conditions
6824 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6825
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6826</div>
6827
6828<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6829<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6830 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6831</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6832
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6833<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6834
6835<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6836<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6837 floating point or vector of floating point type. Not all targets support all
6838 types however.</p>
6839
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6840<pre>
6841 declare float @llvm.pow.f32(float %Val, float %Power)
6842 declare double @llvm.pow.f64(double %Val, double %Power)
6843 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6844 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6845 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6846</pre>
6847
6848<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6849<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6850 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6851
6852<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6853<p>The second argument is a floating point power, and the first is a value to
6854 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6855
6856<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6857<p>This function returns the first value raised to the second power, returning
6858 the same values as the libm <tt>pow</tt> functions would, and handles error
6859 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6860
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6861</div>
6862
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6863</div>
6864
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]6865<!-- _______________________________________________________________________ -->
6866<h4>
6867 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6868</h4>
6869
6870<div>
6871
6872<h5>Syntax:</h5>
6873<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6874 floating point or vector of floating point type. Not all targets support all
6875 types however.</p>
6876
6877<pre>
6878 declare float @llvm.exp.f32(float %Val)
6879 declare double @llvm.exp.f64(double %Val)
6880 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6881 declare fp128 @llvm.exp.f128(fp128 %Val)
6882 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6883</pre>
6884
6885<h5>Overview:</h5>
6886<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6887
6888<h5>Arguments:</h5>
6889<p>The argument and return value are floating point numbers of the same
6890 type.</p>
6891
6892<h5>Semantics:</h5>
6893<p>This function returns the same values as the libm <tt>exp</tt> functions
6894 would, and handles error conditions in the same way.</p>
6895
6896</div>
6897
6898<!-- _______________________________________________________________________ -->
6899<h4>
6900 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6901</h4>
6902
6903<div>
6904
6905<h5>Syntax:</h5>
6906<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6907 floating point or vector of floating point type. Not all targets support all
6908 types however.</p>
6909
6910<pre>
6911 declare float @llvm.log.f32(float %Val)
6912 declare double @llvm.log.f64(double %Val)
6913 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6914 declare fp128 @llvm.log.f128(fp128 %Val)
6915 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6916</pre>
6917
6918<h5>Overview:</h5>
6919<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6920
6921<h5>Arguments:</h5>
6922<p>The argument and return value are floating point numbers of the same
6923 type.</p>
6924
6925<h5>Semantics:</h5>
6926<p>This function returns the same values as the libm <tt>log</tt> functions
6927 would, and handles error conditions in the same way.</p>
6928
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]6929<h4>
6930 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
6931</h4>
6932
6933<div>
6934
6935<h5>Syntax:</h5>
6936<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
6937 floating point or vector of floating point type. Not all targets support all
6938 types however.</p>
6939
6940<pre>
6941 declare float @llvm.fma.f32(float %a, float %b, float %c)
6942 declare double @llvm.fma.f64(double %a, double %b, double %c)
6943 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
6944 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
6945 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
6946</pre>
6947
6948<h5>Overview:</h5>
Cameron Zwarichabc43e62011-07-08 22:13:55 +0000[diff] [blame]6949<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]6950 operation.</p>
6951
6952<h5>Arguments:</h5>
6953<p>The argument and return value are floating point numbers of the same
6954 type.</p>
6955
6956<h5>Semantics:</h5>
6957<p>This function returns the same values as the libm <tt>fma</tt> functions
6958 would.</p>
6959
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]6960</div>
6961
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6962<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6963<h3>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6964 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6965</h3>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6966
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6967<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6968
6969<p>LLVM provides intrinsics for a few important bit manipulation operations.
6970 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6971
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6972<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6973<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6974 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6975</h4>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6976
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6977<div>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6978
6979<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6980<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6981 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6982
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6983<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6984 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6985 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6986 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6987</pre>
6988
6989<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6990<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6991 values with an even number of bytes (positive multiple of 16 bits). These
6992 are useful for performing operations on data that is not in the target's
6993 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6994
6995<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6996<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6997 and low byte of the input i16 swapped. Similarly,
6998 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6999 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
7000 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
7001 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
7002 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
7003 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]7004
7005</div>
7006
7007<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7008<h4>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]7009 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7010</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7011
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7012<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7013
7014<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]7015<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]7016 width, or on any vector with integer elements. Not all targets support all
7017 bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7018
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7019<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7020 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7021 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7022 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7023 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
7024 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7025 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]7026</pre>
7027
7028<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7029<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
7030 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7031
7032<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7033<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]7034 integer type, or a vector with integer elements.
7035 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7036
7037<h5>Semantics:</h5>
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7038<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
7039 element of a vector.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7040
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7041</div>
7042
7043<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7044<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]7045 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7046</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7047
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7048<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7049
7050<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7051<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]7052 integer bit width, or any vector whose elements are integers. Not all
7053 targets support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7054
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7055<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7056 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
7057 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7058 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7059 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
7060 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7061 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]7062</pre>
7063
7064<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7065<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
7066 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7067
7068<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7069<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]7070 integer type, or any vector type with integer element type.
7071 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7072
7073<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7074<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7075 zeros in a variable, or within each element of the vector if the operation
7076 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]7077 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7078
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7079</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]7080
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7081<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7082<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]7083 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7084</h4>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7085
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7086<div>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7087
7088<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7089<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]7090 integer bit width, or any vector of integer elements. Not all targets
7091 support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7092
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7093<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7094 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
7095 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7096 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7097 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
7098 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7099 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]7100</pre>
7101
7102<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7103<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
7104 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7105
7106<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7107<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]7108 integer type, or a vectory with integer element type.. The return type
7109 must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7110
7111<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7112<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7113 zeros in a variable, or within each element of a vector.
7114 If the src == 0 then the result is the size in bits of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7115 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7116
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7117</div>
7118
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7119</div>
7120
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7121<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7122<h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7123 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7124</h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7125
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7126<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7127
7128<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7129
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7130<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7131<h4>
7132 <a name="int_sadd_overflow">
7133 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
7134 </a>
7135</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7136
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7137<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7138
7139<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7140<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]7141 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7142
7143<pre>
7144 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
7145 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7146 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
7147</pre>
7148
7149<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7150<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7151 a signed addition of the two arguments, and indicate whether an overflow
7152 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7153
7154<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7155<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]7156 be of integer types of any bit width, but they must have the same bit
7157 width. The second element of the result structure must be of
7158 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7159 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7160
7161<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7162<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7163 a signed addition of the two variables. They return a structure &mdash; the
7164 first element of which is the signed summation, and the second element of
7165 which is a bit specifying if the signed summation resulted in an
7166 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7167
7168<h5>Examples:</h5>
7169<pre>
7170 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7171 %sum = extractvalue {i32, i1} %res, 0
7172 %obit = extractvalue {i32, i1} %res, 1
7173 br i1 %obit, label %overflow, label %normal
7174</pre>
7175
7176</div>
7177
7178<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7179<h4>
7180 <a name="int_uadd_overflow">
7181 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
7182 </a>
7183</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7184
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7185<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7186
7187<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7188<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]7189 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7190
7191<pre>
7192 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
7193 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7194 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
7195</pre>
7196
7197<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7198<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7199 an unsigned addition of the two arguments, and indicate whether a carry
7200 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7201
7202<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7203<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]7204 be of integer types of any bit width, but they must have the same bit
7205 width. The second element of the result structure must be of
7206 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7207 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7208
7209<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7210<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7211 an unsigned addition of the two arguments. They return a structure &mdash;
7212 the first element of which is the sum, and the second element of which is a
7213 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7214
7215<h5>Examples:</h5>
7216<pre>
7217 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7218 %sum = extractvalue {i32, i1} %res, 0
7219 %obit = extractvalue {i32, i1} %res, 1
7220 br i1 %obit, label %carry, label %normal
7221</pre>
7222
7223</div>
7224
7225<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7226<h4>
7227 <a name="int_ssub_overflow">
7228 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
7229 </a>
7230</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7231
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7232<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7233
7234<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7235<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]7236 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7237
7238<pre>
7239 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
7240 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7241 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
7242</pre>
7243
7244<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7245<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7246 a signed subtraction of the two arguments, and indicate whether an overflow
7247 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7248
7249<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7250<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]7251 be of integer types of any bit width, but they must have the same bit
7252 width. The second element of the result structure must be of
7253 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7254 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7255
7256<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7257<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7258 a signed subtraction of the two arguments. They return a structure &mdash;
7259 the first element of which is the subtraction, and the second element of
7260 which is a bit specifying if the signed subtraction resulted in an
7261 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7262
7263<h5>Examples:</h5>
7264<pre>
7265 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7266 %sum = extractvalue {i32, i1} %res, 0
7267 %obit = extractvalue {i32, i1} %res, 1
7268 br i1 %obit, label %overflow, label %normal
7269</pre>
7270
7271</div>
7272
7273<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7274<h4>
7275 <a name="int_usub_overflow">
7276 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
7277 </a>
7278</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7279
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7280<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7281
7282<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7283<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]7284 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7285
7286<pre>
7287 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
7288 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7289 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
7290</pre>
7291
7292<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7293<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7294 an unsigned subtraction of the two arguments, and indicate whether an
7295 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7296
7297<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7298<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]7299 be of integer types of any bit width, but they must have the same bit
7300 width. The second element of the result structure must be of
7301 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7302 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7303
7304<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7305<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7306 an unsigned subtraction of the two arguments. They return a structure &mdash;
7307 the first element of which is the subtraction, and the second element of
7308 which is a bit specifying if the unsigned subtraction resulted in an
7309 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7310
7311<h5>Examples:</h5>
7312<pre>
7313 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7314 %sum = extractvalue {i32, i1} %res, 0
7315 %obit = extractvalue {i32, i1} %res, 1
7316 br i1 %obit, label %overflow, label %normal
7317</pre>
7318
7319</div>
7320
7321<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7322<h4>
7323 <a name="int_smul_overflow">
7324 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
7325 </a>
7326</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7327
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7328<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7329
7330<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7331<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]7332 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7333
7334<pre>
7335 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
7336 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7337 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
7338</pre>
7339
7340<h5>Overview:</h5>
7341
7342<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7343 a signed multiplication of the two arguments, and indicate whether an
7344 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7345
7346<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7347<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]7348 be of integer types of any bit width, but they must have the same bit
7349 width. The second element of the result structure must be of
7350 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7351 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7352
7353<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7354<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7355 a signed multiplication of the two arguments. They return a structure &mdash;
7356 the first element of which is the multiplication, and the second element of
7357 which is a bit specifying if the signed multiplication resulted in an
7358 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7359
7360<h5>Examples:</h5>
7361<pre>
7362 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7363 %sum = extractvalue {i32, i1} %res, 0
7364 %obit = extractvalue {i32, i1} %res, 1
7365 br i1 %obit, label %overflow, label %normal
7366</pre>
7367
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]7368</div>
7369
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7370<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7371<h4>
7372 <a name="int_umul_overflow">
7373 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7374 </a>
7375</h4>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7376
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7377<div>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7378
7379<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7380<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]7381 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7382
7383<pre>
7384 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7385 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7386 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7387</pre>
7388
7389<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7390<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7391 a unsigned multiplication of the two arguments, and indicate whether an
7392 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7393
7394<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7395<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]7396 be of integer types of any bit width, but they must have the same bit
7397 width. The second element of the result structure must be of
7398 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7399 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7400
7401<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7402<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7403 an unsigned multiplication of the two arguments. They return a structure
7404 &mdash; the first element of which is the multiplication, and the second
7405 element of which is a bit specifying if the unsigned multiplication resulted
7406 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7407
7408<h5>Examples:</h5>
7409<pre>
7410 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7411 %sum = extractvalue {i32, i1} %res, 0
7412 %obit = extractvalue {i32, i1} %res, 1
7413 br i1 %obit, label %overflow, label %normal
7414</pre>
7415
7416</div>
7417
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7418</div>
7419
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7420<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7421<h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7422 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7423</h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7424
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7425<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7426
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7427<p>Half precision floating point is a storage-only format. This means that it is
7428 a dense encoding (in memory) but does not support computation in the
7429 format.</p>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7430
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7431<p>This means that code must first load the half-precision floating point
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7432 value as an i16, then convert it to float with <a
7433 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7434 Computation can then be performed on the float value (including extending to
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7435 double etc). To store the value back to memory, it is first converted to
7436 float if needed, then converted to i16 with
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7437 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7438 storing as an i16 value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7439
7440<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7441<h4>
7442 <a name="int_convert_to_fp16">
7443 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7444 </a>
7445</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7446
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7447<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7448
7449<h5>Syntax:</h5>
7450<pre>
7451 declare i16 @llvm.convert.to.fp16(f32 %a)
7452</pre>
7453
7454<h5>Overview:</h5>
7455<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7456 a conversion from single precision floating point format to half precision
7457 floating point format.</p>
7458
7459<h5>Arguments:</h5>
7460<p>The intrinsic function contains single argument - the value to be
7461 converted.</p>
7462
7463<h5>Semantics:</h5>
7464<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7465 a conversion from single precision floating point format to half precision
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7466 floating point format. The return value is an <tt>i16</tt> which
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7467 contains the converted number.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7468
7469<h5>Examples:</h5>
7470<pre>
7471 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7472 store i16 %res, i16* @x, align 2
7473</pre>
7474
7475</div>
7476
7477<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7478<h4>
7479 <a name="int_convert_from_fp16">
7480 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7481 </a>
7482</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7483
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7484<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7485
7486<h5>Syntax:</h5>
7487<pre>
7488 declare f32 @llvm.convert.from.fp16(i16 %a)
7489</pre>
7490
7491<h5>Overview:</h5>
7492<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7493 a conversion from half precision floating point format to single precision
7494 floating point format.</p>
7495
7496<h5>Arguments:</h5>
7497<p>The intrinsic function contains single argument - the value to be
7498 converted.</p>
7499
7500<h5>Semantics:</h5>
7501<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7502 conversion from half single precision floating point format to single
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7503 precision floating point format. The input half-float value is represented by
7504 an <tt>i16</tt> value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7505
7506<h5>Examples:</h5>
7507<pre>
7508 %a = load i16* @x, align 2
7509 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7510</pre>
7511
7512</div>
7513
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7514</div>
7515
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7516<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7517<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7518 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7519</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7520
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7521<div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7522
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7523<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7524 prefix), are described in
7525 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7526 Level Debugging</a> document.</p>
7527
7528</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7529
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7530<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7531<h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7532 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7533</h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7534
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7535<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7536
7537<p>The LLVM exception handling intrinsics (which all start with
7538 <tt>llvm.eh.</tt> prefix), are described in
7539 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7540 Handling</a> document.</p>
7541
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7542</div>
7543
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7544<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7545<h3>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7546 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7547</h3>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7548
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7549<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7550
7551<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]7552 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7553 The result is a callable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7554 function pointer lacking the nest parameter - the caller does not need to
7555 provide a value for it. Instead, the value to use is stored in advance in a
7556 "trampoline", a block of memory usually allocated on the stack, which also
7557 contains code to splice the nest value into the argument list. This is used
7558 to implement the GCC nested function address extension.</p>
7559
7560<p>For example, if the function is
7561 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7562 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7563 follows:</p>
7564
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]7565<pre class="doc_code">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7566 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7567 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7568 %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]7569 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7570</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7571
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7572<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7573 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7574
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7575<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7576<h4>
7577 <a name="int_it">
7578 '<tt>llvm.init.trampoline</tt>' Intrinsic
7579 </a>
7580</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7581
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7582<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7583
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7584<h5>Syntax:</h5>
7585<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7586 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]7587</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7588
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7589<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7590<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7591 function pointer suitable for executing it.</p>
7592
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7593<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7594<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7595 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7596 sufficiently aligned block of memory; this memory is written to by the
7597 intrinsic. Note that the size and the alignment are target-specific - LLVM
7598 currently provides no portable way of determining them, so a front-end that
7599 generates this intrinsic needs to have some target-specific knowledge.
7600 The <tt>func</tt> argument must hold a function bitcast to
7601 an <tt>i8*</tt>.</p>
7602
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7603<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7604<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7605 dependent code, turning it into a function. A pointer to this function is
7606 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7607 function pointer type</a> before being called. The new function's signature
7608 is the same as that of <tt>func</tt> with any arguments marked with
7609 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7610 is allowed, and it must be of pointer type. Calling the new function is
7611 equivalent to calling <tt>func</tt> with the same argument list, but
7612 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7613 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7614 by <tt>tramp</tt> is modified, then the effect of any later call to the
7615 returned function pointer is undefined.</p>
7616
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7617</div>
7618
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7619</div>
7620
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7621<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7622<h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7623 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7624</h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7625
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7626<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7627
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7628<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7629 hardware constructs for atomic operations and memory synchronization. This
7630 provides an interface to the hardware, not an interface to the programmer. It
7631 is aimed at a low enough level to allow any programming models or APIs
7632 (Application Programming Interfaces) which need atomic behaviors to map
7633 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7634 hardware provides a "universal IR" for source languages, it also provides a
7635 starting point for developing a "universal" atomic operation and
7636 synchronization IR.</p>
7637
7638<p>These do <em>not</em> form an API such as high-level threading libraries,
7639 software transaction memory systems, atomic primitives, and intrinsic
7640 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7641 application libraries. The hardware interface provided by LLVM should allow
7642 a clean implementation of all of these APIs and parallel programming models.
7643 No one model or paradigm should be selected above others unless the hardware
7644 itself ubiquitously does so.</p>
7645
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7646<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7647<h4>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7648 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7649</h4>
7650
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7651<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7652<h5>Syntax:</h5>
7653<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7654 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]7655</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7656
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7657<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7658<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7659 specific pairs of memory access types.</p>
7660
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7661<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7662<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7663 The first four arguments enables a specific barrier as listed below. The
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]7664 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7665 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7666
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7667<ul>
7668 <li><tt>ll</tt>: load-load barrier</li>
7669 <li><tt>ls</tt>: load-store barrier</li>
7670 <li><tt>sl</tt>: store-load barrier</li>
7671 <li><tt>ss</tt>: store-store barrier</li>
7672 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7673</ul>
7674
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7675<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7676<p>This intrinsic causes the system to enforce some ordering constraints upon
7677 the loads and stores of the program. This barrier does not
7678 indicate <em>when</em> any events will occur, it only enforces
7679 an <em>order</em> in which they occur. For any of the specified pairs of load
7680 and store operations (f.ex. load-load, or store-load), all of the first
7681 operations preceding the barrier will complete before any of the second
7682 operations succeeding the barrier begin. Specifically the semantics for each
7683 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7684
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7685<ul>
7686 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7687 after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7688 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7689 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7690 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7691 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7692 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7693 load after the barrier begins.</li>
7694</ul>
7695
7696<p>These semantics are applied with a logical "and" behavior when more than one
7697 is enabled in a single memory barrier intrinsic.</p>
7698
7699<p>Backends may implement stronger barriers than those requested when they do
7700 not support as fine grained a barrier as requested. Some architectures do
7701 not need all types of barriers and on such architectures, these become
7702 noops.</p>
7703
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7704<h5>Example:</h5>
7705<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7706%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7707%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7708 store i32 4, %ptr
7709
7710%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0b0669a2011-06-29 17:14:00 +0000[diff] [blame]7711 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]7712 <i>; guarantee the above finishes</i>
7713 store i32 8, %ptr <i>; before this begins</i>
7714</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7715
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7716</div>
7717
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7718<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7719<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7720 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7721</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7722
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7723<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7724
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7725<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7726<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7727 any integer bit width and for different address spaces. Not all targets
7728 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7729
7730<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7731 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7732 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7733 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7734 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]7735</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7736
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7737<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7738<p>This loads a value in memory and compares it to a given value. If they are
7739 equal, it stores a new value into the memory.</p>
7740
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7741<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7742<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7743 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7744 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7745 this integer type. While any bit width integer may be used, targets may only
7746 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7747
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7748<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7749<p>This entire intrinsic must be executed atomically. It first loads the value
7750 in memory pointed to by <tt>ptr</tt> and compares it with the
7751 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7752 memory. The loaded value is yielded in all cases. This provides the
7753 equivalent of an atomic compare-and-swap operation within the SSA
7754 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7755
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7756<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7757<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7758%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7759%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7760 store i32 4, %ptr
7761
7762%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7763%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7764 <i>; yields {i32}:result1 = 4</i>
7765%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7766%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7767
7768%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7769%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7770 <i>; yields {i32}:result2 = 8</i>
7771%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7772
7773%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7774</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7775
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7776</div>
7777
7778<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7779<h4>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7780 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7781</h4>
7782
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7783<div>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7784<h5>Syntax:</h5>
7785
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7786<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7787 integer bit width. Not all targets support all bit widths however.</p>
7788
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7789<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7790 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7791 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7792 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7793 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]7794</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7795
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7796<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7797<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7798 the value from memory. It then stores the value in <tt>val</tt> in the memory
7799 at <tt>ptr</tt>.</p>
7800
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7801<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7802<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7803 the <tt>val</tt> argument and the result must be integers of the same bit
7804 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7805 integer type. The targets may only lower integer representations they
7806 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7807
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7808<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7809<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7810 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7811 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7812
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7813<h5>Examples:</h5>
7814<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7815%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7816%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7817 store i32 4, %ptr
7818
7819%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7820%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7821 <i>; yields {i32}:result1 = 4</i>
7822%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7823%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7824
7825%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7826%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7827 <i>; yields {i32}:result2 = 8</i>
7828
7829%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7830%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7831</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7832
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7833</div>
7834
7835<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7836<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7837 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7838</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7839
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7840<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7841
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7842<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7843<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7844 any integer bit width. Not all targets support all bit widths however.</p>
7845
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7846<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7847 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7848 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7849 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7850 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]7851</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7852
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7853<h5>Overview:</h5>
7854<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7855 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7856
7857<h5>Arguments:</h5>
7858<p>The intrinsic takes two arguments, the first a pointer to an integer value
7859 and the second an integer value. The result is also an integer value. These
7860 integer types can have any bit width, but they must all have the same bit
7861 width. The targets may only lower integer representations they support.</p>
7862
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7863<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7864<p>This intrinsic does a series of operations atomically. It first loads the
7865 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7866 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]7867
7868<h5>Examples:</h5>
7869<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7870%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7871%ptr = bitcast i8* %mallocP to i32*
7872 store i32 4, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7873%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7874 <i>; yields {i32}:result1 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7875%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7876 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7877%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7878 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7879%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7880</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7881
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7882</div>
7883
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7884<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7885<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7886 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7887</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7888
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7889<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7890
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7891<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7892<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7893 any integer bit width and for different address spaces. Not all targets
7894 support all bit widths however.</p>
7895
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7896<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7897 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7898 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7899 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7900 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]7901</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7902
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7903<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7904<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7905 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7906
7907<h5>Arguments:</h5>
7908<p>The intrinsic takes two arguments, the first a pointer to an integer value
7909 and the second an integer value. The result is also an integer value. These
7910 integer types can have any bit width, but they must all have the same bit
7911 width. The targets may only lower integer representations they support.</p>
7912
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7913<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7914<p>This intrinsic does a series of operations atomically. It first loads the
7915 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7916 result to <tt>ptr</tt>. It yields the original value stored
7917 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7918
7919<h5>Examples:</h5>
7920<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7921%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7922%ptr = bitcast i8* %mallocP to i32*
7923 store i32 8, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7924%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7925 <i>; yields {i32}:result1 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7926%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7927 <i>; yields {i32}:result2 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7928%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7929 <i>; yields {i32}:result3 = 2</i>
7930%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7931</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7932
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7933</div>
7934
7935<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7936<h4>
7937 <a name="int_atomic_load_and">
7938 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7939 </a>
7940 <br>
7941 <a name="int_atomic_load_nand">
7942 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7943 </a>
7944 <br>
7945 <a name="int_atomic_load_or">
7946 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7947 </a>
7948 <br>
7949 <a name="int_atomic_load_xor">
7950 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7951 </a>
7952</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7953
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7954<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7955
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7956<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7957<p>These are overloaded intrinsics. You can
7958 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7959 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7960 bit width and for different address spaces. Not all targets support all bit
7961 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7962
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7963<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7964 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7965 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7966 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7967 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]7968</pre>
7969
7970<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7971 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7972 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7973 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7974 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]7975</pre>
7976
7977<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7978 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7979 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7980 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7981 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]7982</pre>
7983
7984<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7985 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7986 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7987 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7988 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]7989</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7990
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7991<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7992<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7993 the value stored in memory at <tt>ptr</tt>. It yields the original value
7994 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7995
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7996<h5>Arguments:</h5>
7997<p>These intrinsics take two arguments, the first a pointer to an integer value
7998 and the second an integer value. The result is also an integer value. These
7999 integer types can have any bit width, but they must all have the same bit
8000 width. The targets may only lower integer representations they support.</p>
8001
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8002<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8003<p>These intrinsics does a series of operations atomically. They first load the
8004 value stored at <tt>ptr</tt>. They then do the bitwise
8005 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
8006 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8007
8008<h5>Examples:</h5>
8009<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]8010%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8011%ptr = bitcast i8* %mallocP to i32*
8012 store i32 0x0F0F, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8013%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8014 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8015%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8016 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8017%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8018 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8019%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8020 <i>; yields {i32}:result3 = FF</i>
8021%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
8022</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8023
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8024</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8025
8026<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8027<h4>
8028 <a name="int_atomic_load_max">
8029 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
8030 </a>
8031 <br>
8032 <a name="int_atomic_load_min">
8033 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
8034 </a>
8035 <br>
8036 <a name="int_atomic_load_umax">
8037 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
8038 </a>
8039 <br>
8040 <a name="int_atomic_load_umin">
8041 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
8042 </a>
8043</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8044
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8045<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8046
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8047<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8048<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
8049 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
8050 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
8051 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8052
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8053<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8054 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8055 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8056 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8057 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]8058</pre>
8059
8060<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8061 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8062 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8063 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8064 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]8065</pre>
8066
8067<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8068 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8069 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8070 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8071 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]8072</pre>
8073
8074<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8075 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8076 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8077 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8078 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]8079</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8080
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8081<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]8082<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8083 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
8084 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8085
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8086<h5>Arguments:</h5>
8087<p>These intrinsics take two arguments, the first a pointer to an integer value
8088 and the second an integer value. The result is also an integer value. These
8089 integer types can have any bit width, but they must all have the same bit
8090 width. The targets may only lower integer representations they support.</p>
8091
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8092<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8093<p>These intrinsics does a series of operations atomically. They first load the
8094 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
8095 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
8096 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8097
8098<h5>Examples:</h5>
8099<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]8100%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8101%ptr = bitcast i8* %mallocP to i32*
8102 store i32 7, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8103%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8104 <i>; yields {i32}:result0 = 7</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8105%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8106 <i>; yields {i32}:result1 = -2</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8107%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8108 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8109%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8110 <i>; yields {i32}:result3 = 8</i>
8111%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
8112</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8113
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8114</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]8115
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8116</div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8117
8118<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8119<h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8120 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8121</h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8122
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8123<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8124
8125<p>This class of intrinsics exists to information about the lifetime of memory
8126 objects and ranges where variables are immutable.</p>
8127
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8128<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8129<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8130 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8131</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8132
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8133<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8134
8135<h5>Syntax:</h5>
8136<pre>
8137 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8138</pre>
8139
8140<h5>Overview:</h5>
8141<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
8142 object's lifetime.</p>
8143
8144<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8145<p>The first argument is a constant integer representing the size of the
8146 object, or -1 if it is variable sized. The second argument is a pointer to
8147 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8148
8149<h5>Semantics:</h5>
8150<p>This intrinsic indicates that before this point in the code, the value of the
8151 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]8152 never be used and has an undefined value. A load from the pointer that
8153 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8154 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
8155
8156</div>
8157
8158<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8159<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8160 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8161</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8162
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8163<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8164
8165<h5>Syntax:</h5>
8166<pre>
8167 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8168</pre>
8169
8170<h5>Overview:</h5>
8171<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
8172 object's lifetime.</p>
8173
8174<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8175<p>The first argument is a constant integer representing the size of the
8176 object, or -1 if it is variable sized. The second argument is a pointer to
8177 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8178
8179<h5>Semantics:</h5>
8180<p>This intrinsic indicates that after this point in the code, the value of the
8181 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
8182 never be used and has an undefined value. Any stores into the memory object
8183 following this intrinsic may be removed as dead.
8184
8185</div>
8186
8187<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8188<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8189 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8190</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8191
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8192<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8193
8194<h5>Syntax:</h5>
8195<pre>
Nick Lewycky29b6cb42010-11-30 04:13:41 +0000[diff] [blame]8196 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8197</pre>
8198
8199<h5>Overview:</h5>
8200<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
8201 a memory object will not change.</p>
8202
8203<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8204<p>The first argument is a constant integer representing the size of the
8205 object, or -1 if it is variable sized. The second argument is a pointer to
8206 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8207
8208<h5>Semantics:</h5>
8209<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
8210 the return value, the referenced memory location is constant and
8211 unchanging.</p>
8212
8213</div>
8214
8215<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8216<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8217 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8218</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8219
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8220<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8221
8222<h5>Syntax:</h5>
8223<pre>
8224 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8225</pre>
8226
8227<h5>Overview:</h5>
8228<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
8229 a memory object are mutable.</p>
8230
8231<h5>Arguments:</h5>
8232<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8233 The second argument is a constant integer representing the size of the
8234 object, or -1 if it is variable sized and the third argument is a pointer
8235 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8236
8237<h5>Semantics:</h5>
8238<p>This intrinsic indicates that the memory is mutable again.</p>
8239
8240</div>
8241
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8242</div>
8243
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]8244<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8245<h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8246 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8247</h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8248
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8249<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8250
8251<p>This class of intrinsics is designed to be generic and has no specific
8252 purpose.</p>
8253
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8254<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8255<h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8256 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8257</h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8258
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8259<div>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8260
8261<h5>Syntax:</h5>
8262<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8263 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]8264</pre>
8265
8266<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8267<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8268
8269<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8270<p>The first argument is a pointer to a value, the second is a pointer to a
8271 global string, the third is a pointer to a global string which is the source
8272 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8273
8274<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8275<p>This intrinsic allows annotation of local variables with arbitrary strings.
8276 This can be useful for special purpose optimizations that want to look for
8277 these annotations. These have no other defined use, they are ignored by code
8278 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8279
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8280</div>
8281
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8282<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8283<h4>
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]8284 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8285</h4>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8286
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8287<div>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8288
8289<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8290<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
8291 any integer bit width.</p>
8292
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8293<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8294 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8295 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8296 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8297 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8298 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]8299</pre>
8300
8301<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8302<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8303
8304<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8305<p>The first argument is an integer value (result of some expression), the
8306 second is a pointer to a global string, the third is a pointer to a global
8307 string which is the source file name, and the last argument is the line
8308 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8309
8310<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8311<p>This intrinsic allows annotations to be put on arbitrary expressions with
8312 arbitrary strings. This can be useful for special purpose optimizations that
8313 want to look for these annotations. These have no other defined use, they
8314 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8315
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8316</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]8317
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8318<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8319<h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8320 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8321</h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8322
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8323<div>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8324
8325<h5>Syntax:</h5>
8326<pre>
8327 declare void @llvm.trap()
8328</pre>
8329
8330<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8331<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8332
8333<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8334<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8335
8336<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8337<p>This intrinsics is lowered to the target dependent trap instruction. If the
8338 target does not have a trap instruction, this intrinsic will be lowered to
8339 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8340
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8341</div>
8342
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8343<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8344<h4>
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]8345 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8346</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8347
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8348<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8349
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8350<h5>Syntax:</h5>
8351<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8352 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8353</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8354
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8355<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8356<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8357 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8358 ensure that it is placed on the stack before local variables.</p>
8359
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8360<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8361<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8362 arguments. The first argument is the value loaded from the stack
8363 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8364 that has enough space to hold the value of the guard.</p>
8365
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8366<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8367<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8368 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8369 stack. This is to ensure that if a local variable on the stack is
8370 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8371 the guard on the stack is checked against the original guard. If they are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8372 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8373 function.</p>
8374
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8375</div>
8376
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8377<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8378<h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8379 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8380</h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8381
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8382<div>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8383
8384<h5>Syntax:</h5>
8385<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8386 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8387 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8388</pre>
8389
8390<h5>Overview:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8391<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8392 the optimizers to determine at compile time whether a) an operation (like
8393 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8394 runtime check for overflow isn't necessary. An object in this context means
8395 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8396
8397<h5>Arguments:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8398<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]8399 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8400 is a boolean 0 or 1. This argument determines whether you want the
8401 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]8402 1, variables are not allowed.</p>
8403
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8404<h5>Semantics:</h5>
8405<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8406 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8407 depending on the <tt>type</tt> argument, if the size cannot be determined at
8408 compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8409
8410</div>
8411
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8412</div>
8413
8414</div>
8415
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8416<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8417<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8418<address>
8419 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]8420 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8421 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]8422 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]8423
8424 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]8425 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8426 Last modified: $Date$
8427</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]8428
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]8429</body>
8430</html>