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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 47f3513dd574535aeb40c9eb11134f0899e92269 / . / 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>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]57 </ol>
58 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]59 <li><a href="#typesystem">Type System</a>
60 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]61 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]62 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]63 <ol>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]64 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]65 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]66 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]67 <li><a href="#t_void">Void Type</a></li>
68 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]69 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]70 </ol>
71 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]72 <li><a href="#t_derived">Derived Types</a>
73 <ol>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]74 <li><a href="#t_aggregate">Aggregate Types</a>
75 <ol>
76 <li><a href="#t_array">Array Type</a></li>
77 <li><a href="#t_struct">Structure Type</a></li>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]78 <li><a href="#t_opaque">Opaque Structure Types</a></li>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]79 <li><a href="#t_vector">Vector Type</a></li>
80 </ol>
81 </li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]82 <li><a href="#t_function">Function Type</a></li>
83 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]84 </ol>
85 </li>
86 </ol>
87 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]88 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]89 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]90 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]91 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]92 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
93 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]94 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]95 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]96 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]97 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]98 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]99 <li><a href="#othervalues">Other Values</a>
100 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]101 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]102 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]103 </ol>
104 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]105 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
106 <ol>
107 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]108 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
109 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]110 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
111 Global Variable</a></li>
112 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
113 Global Variable</a></li>
114 </ol>
115 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]116 <li><a href="#instref">Instruction Reference</a>
117 <ol>
118 <li><a href="#terminators">Terminator Instructions</a>
119 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]120 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
121 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]122 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]123 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]124 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]125 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]126 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]127 </ol>
128 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]129 <li><a href="#binaryops">Binary Operations</a>
130 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]131 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]132 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]133 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]134 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]135 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]136 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]137 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
138 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
139 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]140 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
141 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
142 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]143 </ol>
144 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]145 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
146 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]147 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
148 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
149 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]150 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]151 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]152 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]153 </ol>
154 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]155 <li><a href="#vectorops">Vector Operations</a>
156 <ol>
157 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
158 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
159 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]160 </ol>
161 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]162 <li><a href="#aggregateops">Aggregate Operations</a>
163 <ol>
164 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
165 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
166 </ol>
167 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]168 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]169 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]170 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]171 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
172 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame^]173 <li><a href="#i_fence">'<tt>fence</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]174 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]175 </ol>
176 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]177 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]178 <ol>
179 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
180 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
181 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
182 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
183 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]184 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
185 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
186 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
187 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]188 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
189 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]190 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]191 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]192 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]193 <li><a href="#otherops">Other Operations</a>
194 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]195 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
196 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]197 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]198 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]199 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]200 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]201 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]202 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]203 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]204 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]205 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]206 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]207 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
208 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]209 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
210 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
211 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]212 </ol>
213 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]214 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
215 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]216 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
217 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
218 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]219 </ol>
220 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]221 <li><a href="#int_codegen">Code Generator Intrinsics</a>
222 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]223 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
224 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
225 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
226 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
227 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
228 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohman31f1af12010-05-26 21:56:15 +0000[diff] [blame]229 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]230 </ol>
231 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]232 <li><a href="#int_libc">Standard C Library Intrinsics</a>
233 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]234 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
235 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
237 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
238 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]239 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
240 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
241 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohman08b280b2011-05-27 00:36:31 +0000[diff] [blame]242 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
243 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]244 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]245 </ol>
246 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]247 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]248 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]249 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]250 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
251 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
252 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]253 </ol>
254 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]255 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
256 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]257 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
258 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
259 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
260 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
261 <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]262 <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]263 </ol>
264 </li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]265 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
266 <ol>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]267 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
268 <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]269 </ol>
270 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]271 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]272 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]273 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]274 <ol>
275 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]276 </ol>
277 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]278 <li><a href="#int_atomics">Atomic intrinsics</a>
279 <ol>
280 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
281 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
282 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
283 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
284 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
285 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
286 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
287 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
288 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
289 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
290 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
291 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
292 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
293 </ol>
294 </li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]295 <li><a href="#int_memorymarkers">Memory Use Markers</a>
296 <ol>
297 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
298 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
299 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
300 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
301 </ol>
302 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]303 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]304 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]305 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]306 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]307 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]308 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]309 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]310 '<tt>llvm.trap</tt>' Intrinsic</a></li>
311 <li><a href="#int_stackprotector">
312 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]313 <li><a href="#int_objectsize">
314 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]315 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]316 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]317 </ol>
318 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]319</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]320
321<div class="doc_author">
322 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
323 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]324</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]325
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]326<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]327<h2><a name="abstract">Abstract</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]328<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]329
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]330<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]331
332<p>This document is a reference manual for the LLVM assembly language. LLVM is
333 a Static Single Assignment (SSA) based representation that provides type
334 safety, low-level operations, flexibility, and the capability of representing
335 'all' high-level languages cleanly. It is the common code representation
336 used throughout all phases of the LLVM compilation strategy.</p>
337
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]338</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]339
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]340<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]341<h2><a name="introduction">Introduction</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]342<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]343
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]344<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]345
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]346<p>The LLVM code representation is designed to be used in three different forms:
347 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
348 for fast loading by a Just-In-Time compiler), and as a human readable
349 assembly language representation. This allows LLVM to provide a powerful
350 intermediate representation for efficient compiler transformations and
351 analysis, while providing a natural means to debug and visualize the
352 transformations. The three different forms of LLVM are all equivalent. This
353 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]354
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]355<p>The LLVM representation aims to be light-weight and low-level while being
356 expressive, typed, and extensible at the same time. It aims to be a
357 "universal IR" of sorts, by being at a low enough level that high-level ideas
358 may be cleanly mapped to it (similar to how microprocessors are "universal
359 IR's", allowing many source languages to be mapped to them). By providing
360 type information, LLVM can be used as the target of optimizations: for
361 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]362 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]363 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]364
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]365<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]366<h4>
367 <a name="wellformed">Well-Formedness</a>
368</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]369
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]370<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]371
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]372<p>It is important to note that this document describes 'well formed' LLVM
373 assembly language. There is a difference between what the parser accepts and
374 what is considered 'well formed'. For example, the following instruction is
375 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]376
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]377<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]378%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]379</pre>
380
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]381<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
382 LLVM infrastructure provides a verification pass that may be used to verify
383 that an LLVM module is well formed. This pass is automatically run by the
384 parser after parsing input assembly and by the optimizer before it outputs
385 bitcode. The violations pointed out by the verifier pass indicate bugs in
386 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]387
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]388</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]389
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]390</div>
391
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]392<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]393
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]394<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]395<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]396<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]397
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]398<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]399
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]400<p>LLVM identifiers come in two basic types: global and local. Global
401 identifiers (functions, global variables) begin with the <tt>'@'</tt>
402 character. Local identifiers (register names, types) begin with
403 the <tt>'%'</tt> character. Additionally, there are three different formats
404 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]405
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]406<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]407 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]408 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
409 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
410 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
411 other characters in their names can be surrounded with quotes. Special
412 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
413 ASCII code for the character in hexadecimal. In this way, any character
414 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]415
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]416 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]417 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]418
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]419 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]420 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]421</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]422
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]423<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]424 don't need to worry about name clashes with reserved words, and the set of
425 reserved words may be expanded in the future without penalty. Additionally,
426 unnamed identifiers allow a compiler to quickly come up with a temporary
427 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]428
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]429<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]430 languages. There are keywords for different opcodes
431 ('<tt><a href="#i_add">add</a></tt>',
432 '<tt><a href="#i_bitcast">bitcast</a></tt>',
433 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
434 ('<tt><a href="#t_void">void</a></tt>',
435 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
436 reserved words cannot conflict with variable names, because none of them
437 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]438
439<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]440 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]441
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]442<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]443
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]444<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]445%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]446</pre>
447
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]448<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]449
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]450<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]451%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]452</pre>
453
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]454<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]455
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]456<pre class="doc_code">
Gabor Greifec58f752009-10-28 13:05:07 +0000[diff] [blame]457%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
458%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]459%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]460</pre>
461
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]462<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
463 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]464
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]465<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]466 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]467 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]468
469 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]470 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]471
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]472 <li>Unnamed temporaries are numbered sequentially</li>
473</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]474
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]475<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]476 demonstrating instructions, we will follow an instruction with a comment that
477 defines the type and name of value produced. Comments are shown in italic
478 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]479
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]480</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]481
482<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]483<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]484<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]485<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]486<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]487<h3>
488 <a name="modulestructure">Module Structure</a>
489</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]490
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]491<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]492
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]493<p>LLVM programs are composed of "Module"s, each of which is a translation unit
494 of the input programs. Each module consists of functions, global variables,
495 and symbol table entries. Modules may be combined together with the LLVM
496 linker, which merges function (and global variable) definitions, resolves
497 forward declarations, and merges symbol table entries. Here is an example of
498 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]499
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]500<pre class="doc_code">
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]501<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckydb9cd762011-01-29 01:09:53 +0000[diff] [blame]502<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]503
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]504<i>; External declaration of the puts function</i>&nbsp;
505<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]506
507<i>; Definition of main function</i>
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]508define i32 @main() { <i>; i32()* </i>&nbsp;
509 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
510 %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]511
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]512 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
513 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
514 <a href="#i_ret">ret</a> i32 0&nbsp;
515}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]516
517<i>; Named metadata</i>
518!1 = metadata !{i32 41}
519!foo = !{!1, null}
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]520</pre>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]521
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]522<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]523 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]524 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]525 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
526 "<tt>foo"</tt>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]527
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]528<p>In general, a module is made up of a list of global values, where both
529 functions and global variables are global values. Global values are
530 represented by a pointer to a memory location (in this case, a pointer to an
531 array of char, and a pointer to a function), and have one of the
532 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]533
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]534</div>
535
536<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]537<h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]538 <a name="linkage">Linkage Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]539</h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]540
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]541<div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]542
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]543<p>All Global Variables and Functions have one of the following types of
544 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]545
546<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]547 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]548 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
549 by objects in the current module. In particular, linking code into a
550 module with an private global value may cause the private to be renamed as
551 necessary to avoid collisions. Because the symbol is private to the
552 module, all references can be updated. This doesn't show up in any symbol
553 table in the object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]554
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]555 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]556 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
557 assembler and evaluated by the linker. Unlike normal strong symbols, they
558 are removed by the linker from the final linked image (executable or
559 dynamic library).</dd>
560
561 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
562 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
563 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
564 linker. The symbols are removed by the linker from the final linked image
565 (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]566
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]567 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
568 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
569 of the object is not taken. For instance, functions that had an inline
570 definition, but the compiler decided not to inline it. Note,
571 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
572 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
573 visibility. The symbols are removed by the linker from the final linked
574 image (executable or dynamic library).</dd>
575
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]576 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling07d31772010-06-29 22:34:52 +0000[diff] [blame]577 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]578 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
579 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]580
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]581 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]582 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]583 into the object file corresponding to the LLVM module. They exist to
584 allow inlining and other optimizations to take place given knowledge of
585 the definition of the global, which is known to be somewhere outside the
586 module. Globals with <tt>available_externally</tt> linkage are allowed to
587 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
588 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]589
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]590 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]591 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]592 the same name when linkage occurs. This can be used to implement
593 some forms of inline functions, templates, or other code which must be
594 generated in each translation unit that uses it, but where the body may
595 be overridden with a more definitive definition later. Unreferenced
596 <tt>linkonce</tt> globals are allowed to be discarded. Note that
597 <tt>linkonce</tt> linkage does not actually allow the optimizer to
598 inline the body of this function into callers because it doesn't know if
599 this definition of the function is the definitive definition within the
600 program or whether it will be overridden by a stronger definition.
601 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
602 linkage.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]603
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]604 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]605 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
606 <tt>linkonce</tt> linkage, except that unreferenced globals with
607 <tt>weak</tt> linkage may not be discarded. This is used for globals that
608 are declared "weak" in C source code.</dd>
609
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]610 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]611 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
612 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
613 global scope.
614 Symbols with "<tt>common</tt>" linkage are merged in the same way as
615 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]616 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]617 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]618 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
619 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]620
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]621
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]622 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]623 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]624 pointer to array type. When two global variables with appending linkage
625 are linked together, the two global arrays are appended together. This is
626 the LLVM, typesafe, equivalent of having the system linker append together
627 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]628
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]629 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]630 <dd>The semantics of this linkage follow the ELF object file model: the symbol
631 is weak until linked, if not linked, the symbol becomes null instead of
632 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]633
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]634 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
635 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]636 <dd>Some languages allow differing globals to be merged, such as two functions
637 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]638 that only equivalent globals are ever merged (the "one definition rule"
639 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]640 and <tt>weak_odr</tt> linkage types to indicate that the global will only
641 be merged with equivalent globals. These linkage types are otherwise the
642 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]643
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]644 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]645 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]646 visible, meaning that it participates in linkage and can be used to
647 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]648</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]649
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]650<p>The next two types of linkage are targeted for Microsoft Windows platform
651 only. They are designed to support importing (exporting) symbols from (to)
652 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]653
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]654<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]655 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]656 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]657 or variable via a global pointer to a pointer that is set up by the DLL
658 exporting the symbol. On Microsoft Windows targets, the pointer name is
659 formed by combining <code>__imp_</code> and the function or variable
660 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]661
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]662 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]663 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]664 pointer to a pointer in a DLL, so that it can be referenced with the
665 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
666 name is formed by combining <code>__imp_</code> and the function or
667 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]668</dl>
669
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]670<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
671 another module defined a "<tt>.LC0</tt>" variable and was linked with this
672 one, one of the two would be renamed, preventing a collision. Since
673 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
674 declarations), they are accessible outside of the current module.</p>
675
676<p>It is illegal for a function <i>declaration</i> to have any linkage type
677 other than "externally visible", <tt>dllimport</tt>
678 or <tt>extern_weak</tt>.</p>
679
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]680<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]681 or <tt>weak_odr</tt> linkages.</p>
682
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]683</div>
684
685<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]686<h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]687 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]688</h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]689
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]690<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]691
692<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]693 and <a href="#i_invoke">invokes</a> can all have an optional calling
694 convention specified for the call. The calling convention of any pair of
695 dynamic caller/callee must match, or the behavior of the program is
696 undefined. The following calling conventions are supported by LLVM, and more
697 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]698
699<dl>
700 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]701 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]702 specified) matches the target C calling conventions. This calling
703 convention supports varargs function calls and tolerates some mismatch in
704 the declared prototype and implemented declaration of the function (as
705 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]706
707 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]708 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]709 (e.g. by passing things in registers). This calling convention allows the
710 target to use whatever tricks it wants to produce fast code for the
711 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]712 (Application Binary Interface).
713 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]714 when this or the GHC convention is used.</a> This calling convention
715 does not support varargs and requires the prototype of all callees to
716 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]717
718 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]719 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]720 as possible under the assumption that the call is not commonly executed.
721 As such, these calls often preserve all registers so that the call does
722 not break any live ranges in the caller side. This calling convention
723 does not support varargs and requires the prototype of all callees to
724 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]725
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]726 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
727 <dd>This calling convention has been implemented specifically for use by the
728 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
729 It passes everything in registers, going to extremes to achieve this by
730 disabling callee save registers. This calling convention should not be
731 used lightly but only for specific situations such as an alternative to
732 the <em>register pinning</em> performance technique often used when
733 implementing functional programming languages.At the moment only X86
734 supports this convention and it has the following limitations:
735 <ul>
736 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
737 floating point types are supported.</li>
738 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
739 6 floating point parameters.</li>
740 </ul>
741 This calling convention supports
742 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
743 requires both the caller and callee are using it.
744 </dd>
745
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]746 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]747 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]748 target-specific calling conventions to be used. Target specific calling
749 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]750</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]751
752<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]753 support Pascal conventions or any other well-known target-independent
754 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]755
756</div>
757
758<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]759<h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]760 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]761</h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]762
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]763<div>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]764
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]765<p>All Global Variables and Functions have one of the following visibility
766 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]767
768<dl>
769 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]770 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]771 that the declaration is visible to other modules and, in shared libraries,
772 means that the declared entity may be overridden. On Darwin, default
773 visibility means that the declaration is visible to other modules. Default
774 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]775
776 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]777 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]778 object if they are in the same shared object. Usually, hidden visibility
779 indicates that the symbol will not be placed into the dynamic symbol
780 table, so no other module (executable or shared library) can reference it
781 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]782
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]783 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]784 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]785 the dynamic symbol table, but that references within the defining module
786 will bind to the local symbol. That is, the symbol cannot be overridden by
787 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]788</dl>
789
790</div>
791
792<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]793<h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]794 <a name="namedtypes">Named Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]795</h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]796
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]797<div>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]798
799<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]800 it easier to read the IR and make the IR more condensed (particularly when
801 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]802
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]803<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]804%mytype = type { %mytype*, i32 }
805</pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]806
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]807<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattnerdc65f222010-08-17 23:26:04 +0000[diff] [blame]808 "<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]809 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]810
811<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]812 and that you can therefore specify multiple names for the same type. This
813 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
814 uses structural typing, the name is not part of the type. When printing out
815 LLVM IR, the printer will pick <em>one name</em> to render all types of a
816 particular shape. This means that if you have code where two different
817 source types end up having the same LLVM type, that the dumper will sometimes
818 print the "wrong" or unexpected type. This is an important design point and
819 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]820
821</div>
822
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]823<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]824<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]825 <a name="globalvars">Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]826</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]827
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]828<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]829
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]830<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]831 instead of run-time. Global variables may optionally be initialized, may
832 have an explicit section to be placed in, and may have an optional explicit
833 alignment specified. A variable may be defined as "thread_local", which
834 means that it will not be shared by threads (each thread will have a
835 separated copy of the variable). A variable may be defined as a global
836 "constant," which indicates that the contents of the variable
837 will <b>never</b> be modified (enabling better optimization, allowing the
838 global data to be placed in the read-only section of an executable, etc).
839 Note that variables that need runtime initialization cannot be marked
840 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]841
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]842<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
843 constant, even if the final definition of the global is not. This capability
844 can be used to enable slightly better optimization of the program, but
845 requires the language definition to guarantee that optimizations based on the
846 'constantness' are valid for the translation units that do not include the
847 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]848
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]849<p>As SSA values, global variables define pointer values that are in scope
850 (i.e. they dominate) all basic blocks in the program. Global variables
851 always define a pointer to their "content" type because they describe a
852 region of memory, and all memory objects in LLVM are accessed through
853 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]854
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]855<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
856 that the address is not significant, only the content. Constants marked
Rafael Espindolaa5eaa862011-01-15 08:20:57 +0000[diff] [blame]857 like this can be merged with other constants if they have the same
858 initializer. Note that a constant with significant address <em>can</em>
859 be merged with a <tt>unnamed_addr</tt> constant, the result being a
860 constant whose address is significant.</p>
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]861
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]862<p>A global variable may be declared to reside in a target-specific numbered
863 address space. For targets that support them, address spaces may affect how
864 optimizations are performed and/or what target instructions are used to
865 access the variable. The default address space is zero. The address space
866 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]867
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]868<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]869 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]870
Chris Lattnerce99fa92010-04-28 00:13:42 +0000[diff] [blame]871<p>An explicit alignment may be specified for a global, which must be a power
872 of 2. If not present, or if the alignment is set to zero, the alignment of
873 the global is set by the target to whatever it feels convenient. If an
874 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner2d4b8ee2010-04-28 00:31:12 +0000[diff] [blame]875 alignment. Targets and optimizers are not allowed to over-align the global
876 if the global has an assigned section. In this case, the extra alignment
877 could be observable: for example, code could assume that the globals are
878 densely packed in their section and try to iterate over them as an array,
879 alignment padding would break this iteration.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]880
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]881<p>For example, the following defines a global in a numbered address space with
882 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]883
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]884<pre class="doc_code">
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]885@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]886</pre>
887
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]888</div>
889
890
891<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]892<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]893 <a name="functionstructure">Functions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]894</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]895
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]896<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]897
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]898<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]899 optional <a href="#linkage">linkage type</a>, an optional
900 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]901 <a href="#callingconv">calling convention</a>,
902 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]903 <a href="#paramattrs">parameter attribute</a> for the return type, a function
904 name, a (possibly empty) argument list (each with optional
905 <a href="#paramattrs">parameter attributes</a>), optional
906 <a href="#fnattrs">function attributes</a>, an optional section, an optional
907 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
908 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]909
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]910<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
911 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]912 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]913 <a href="#callingconv">calling convention</a>,
914 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]915 <a href="#paramattrs">parameter attribute</a> for the return type, a function
916 name, a possibly empty list of arguments, an optional alignment, and an
917 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]918
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]919<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]920 (Control Flow Graph) for the function. Each basic block may optionally start
921 with a label (giving the basic block a symbol table entry), contains a list
922 of instructions, and ends with a <a href="#terminators">terminator</a>
923 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]924
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]925<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]926 executed on entrance to the function, and it is not allowed to have
927 predecessor basic blocks (i.e. there can not be any branches to the entry
928 block of a function). Because the block can have no predecessors, it also
929 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]930
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]931<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]932 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]933
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]934<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]935 the alignment is set to zero, the alignment of the function is set by the
936 target to whatever it feels convenient. If an explicit alignment is
937 specified, the function is forced to have at least that much alignment. All
938 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]939
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]940<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
941 be significant and two identical functions can be merged</p>.
942
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]943<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]944<pre class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]945define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]946 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
947 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
948 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
949 [<a href="#gc">gc</a>] { ... }
950</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]951
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]952</div>
953
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]954<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]955<h3>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]956 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]957</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]958
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]959<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]960
961<p>Aliases act as "second name" for the aliasee value (which can be either
962 function, global variable, another alias or bitcast of global value). Aliases
963 may have an optional <a href="#linkage">linkage type</a>, and an
964 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]965
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]966<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]967<pre class="doc_code">
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]968@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]969</pre>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]970
971</div>
972
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]973<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]974<h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]975 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]976</h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]977
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]978<div>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]979
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]980<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]981 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]982 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]983
984<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]985<pre class="doc_code">
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]986; Some unnamed metadata nodes, which are referenced by the named metadata.
987!0 = metadata !{metadata !"zero"}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]988!1 = metadata !{metadata !"one"}
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]989!2 = metadata !{metadata !"two"}
Dan Gohman1005bc52010-07-13 19:48:13 +0000[diff] [blame]990; A named metadata.
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]991!name = !{!0, !1, !2}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]992</pre>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]993
994</div>
995
996<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]997<h3>
998 <a name="paramattrs">Parameter Attributes</a>
999</h3>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1000
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1001<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1002
1003<p>The return type and each parameter of a function type may have a set of
1004 <i>parameter attributes</i> associated with them. Parameter attributes are
1005 used to communicate additional information about the result or parameters of
1006 a function. Parameter attributes are considered to be part of the function,
1007 not of the function type, so functions with different parameter attributes
1008 can have the same function type.</p>
1009
1010<p>Parameter attributes are simple keywords that follow the type specified. If
1011 multiple parameter attributes are needed, they are space separated. For
1012 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1013
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1014<pre class="doc_code">
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]1015declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]1016declare i32 @atoi(i8 zeroext)
1017declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1018</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1019
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1020<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1021 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1022
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1023<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1024
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1025<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1026 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1027 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichebe81732011-03-16 22:20:18 +0000[diff] [blame]1028 should be zero-extended to the extent required by the target's ABI (which
1029 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1030 parameter) or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1031
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1032 <dt><tt><b>signext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1033 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich9e69ff92011-03-17 14:21:58 +0000[diff] [blame]1034 should be sign-extended to the extent required by the target's ABI (which
1035 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1036 return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1037
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1038 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1039 <dd>This indicates that this parameter or return value should be treated in a
1040 special target-dependent fashion during while emitting code for a function
1041 call or return (usually, by putting it in a register as opposed to memory,
1042 though some targets use it to distinguish between two different kinds of
1043 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1044
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1045 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1046 <dd><p>This indicates that the pointer parameter should really be passed by
1047 value to the function. The attribute implies that a hidden copy of the
1048 pointee
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1049 is made between the caller and the callee, so the callee is unable to
1050 modify the value in the callee. This attribute is only valid on LLVM
1051 pointer arguments. It is generally used to pass structs and arrays by
1052 value, but is also valid on pointers to scalars. The copy is considered
1053 to belong to the caller not the callee (for example,
1054 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1055 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1056 values.</p>
1057
1058 <p>The byval attribute also supports specifying an alignment with
1059 the align attribute. It indicates the alignment of the stack slot to
1060 form and the known alignment of the pointer specified to the call site. If
1061 the alignment is not specified, then the code generator makes a
1062 target-specific assumption.</p></dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1063
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1064 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1065 <dd>This indicates that the pointer parameter specifies the address of a
1066 structure that is the return value of the function in the source program.
1067 This pointer must be guaranteed by the caller to be valid: loads and
1068 stores to the structure may be assumed by the callee to not to trap. This
1069 may only be applied to the first parameter. This is not a valid attribute
1070 for return values. </dd>
1071
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1072 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1073 <dd>This indicates that pointer values
1074 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmanefca7f92010-07-02 23:46:54 +0000[diff] [blame]1075 value do not alias pointer values which are not <i>based</i> on it,
1076 ignoring certain "irrelevant" dependencies.
1077 For a call to the parent function, dependencies between memory
1078 references from before or after the call and from those during the call
1079 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1080 return value used in that call.
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1081 The caller shares the responsibility with the callee for ensuring that
1082 these requirements are met.
1083 For further details, please see the discussion of the NoAlias response in
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1084 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1085<br>
John McCall191d4ee2010-07-06 21:07:14 +0000[diff] [blame]1086 Note that this definition of <tt>noalias</tt> is intentionally
1087 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner211244a2010-07-06 20:51:35 +0000[diff] [blame]1088 arguments, though it is slightly weaker.
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1089<br>
1090 For function return values, C99's <tt>restrict</tt> is not meaningful,
1091 while LLVM's <tt>noalias</tt> is.
1092 </dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1093
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1094 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1095 <dd>This indicates that the callee does not make any copies of the pointer
1096 that outlive the callee itself. This is not a valid attribute for return
1097 values.</dd>
1098
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1099 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1100 <dd>This indicates that the pointer parameter can be excised using the
1101 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1102 attribute for return values.</dd>
1103</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1104
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1105</div>
1106
1107<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1108<h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1109 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1110</h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1111
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1112<div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1113
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1114<p>Each function may specify a garbage collector name, which is simply a
1115 string:</p>
1116
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1117<pre class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1118define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1119</pre>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1120
1121<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1122 collector which will cause the compiler to alter its output in order to
1123 support the named garbage collection algorithm.</p>
1124
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1125</div>
1126
1127<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1128<h3>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1129 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1130</h3>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1131
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1132<div>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1133
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1134<p>Function attributes are set to communicate additional information about a
1135 function. Function attributes are considered to be part of the function, not
1136 of the function type, so functions with different parameter attributes can
1137 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1138
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1139<p>Function attributes are simple keywords that follow the type specified. If
1140 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1141
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1142<pre class="doc_code">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1143define void @f() noinline { ... }
1144define void @f() alwaysinline { ... }
1145define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1146define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1147</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1148
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1149<dl>
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1150 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1151 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1152 the backend should forcibly align the stack pointer. Specify the
1153 desired alignment, which must be a power of two, in parentheses.
1154
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1155 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1156 <dd>This attribute indicates that the inliner should attempt to inline this
1157 function into callers whenever possible, ignoring any active inlining size
1158 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1159
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1160 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis6f12e292010-10-25 16:29:03 +0000[diff] [blame]1161 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis0076d202010-10-25 19:07:39 +0000[diff] [blame]1162 meaning the function can be patched and/or hooked even while it is
1163 loaded into memory. On x86, the function prologue will be preceded
1164 by six bytes of padding and will begin with a two-byte instruction.
1165 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1166 higher were compiled in this fashion.</dd>
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1167
Dan Gohman129bd562011-06-16 16:03:13 +0000[diff] [blame]1168 <dt><tt><b>nonlazybind</b></tt></dt>
1169 <dd>This attribute suppresses lazy symbol binding for the function. This
1170 may make calls to the function faster, at the cost of extra program
1171 startup time if the function is not called during program startup.</dd>
1172
Jakob Stoklund Olesen570a4a52010-02-06 01:16:28 +0000[diff] [blame]1173 <dt><tt><b>inlinehint</b></tt></dt>
1174 <dd>This attribute indicates that the source code contained a hint that inlining
1175 this function is desirable (such as the "inline" keyword in C/C++). It
1176 is just a hint; it imposes no requirements on the inliner.</dd>
1177
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1178 <dt><tt><b>naked</b></tt></dt>
1179 <dd>This attribute disables prologue / epilogue emission for the function.
1180 This can have very system-specific consequences.</dd>
1181
1182 <dt><tt><b>noimplicitfloat</b></tt></dt>
1183 <dd>This attributes disables implicit floating point instructions.</dd>
1184
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1185 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1186 <dd>This attribute indicates that the inliner should never inline this
1187 function in any situation. This attribute may not be used together with
1188 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1189
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1190 <dt><tt><b>noredzone</b></tt></dt>
1191 <dd>This attribute indicates that the code generator should not use a red
1192 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1193
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1194 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1195 <dd>This function attribute indicates that the function never returns
1196 normally. This produces undefined behavior at runtime if the function
1197 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1198
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1199 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1200 <dd>This function attribute indicates that the function never returns with an
1201 unwind or exceptional control flow. If the function does unwind, its
1202 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1203
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1204 <dt><tt><b>optsize</b></tt></dt>
1205 <dd>This attribute suggests that optimization passes and code generator passes
1206 make choices that keep the code size of this function low, and otherwise
1207 do optimizations specifically to reduce code size.</dd>
1208
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1209 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1210 <dd>This attribute indicates that the function computes its result (or decides
1211 to unwind an exception) based strictly on its arguments, without
1212 dereferencing any pointer arguments or otherwise accessing any mutable
1213 state (e.g. memory, control registers, etc) visible to caller functions.
1214 It does not write through any pointer arguments
1215 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1216 changes any state visible to callers. This means that it cannot unwind
1217 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1218 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1219
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1220 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1221 <dd>This attribute indicates that the function does not write through any
1222 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1223 arguments) or otherwise modify any state (e.g. memory, control registers,
1224 etc) visible to caller functions. It may dereference pointer arguments
1225 and read state that may be set in the caller. A readonly function always
1226 returns the same value (or unwinds an exception identically) when called
1227 with the same set of arguments and global state. It cannot unwind an
1228 exception by calling the <tt>C++</tt> exception throwing methods, but may
1229 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1230
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1231 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1232 <dd>This attribute indicates that the function should emit a stack smashing
1233 protector. It is in the form of a "canary"&mdash;a random value placed on
1234 the stack before the local variables that's checked upon return from the
1235 function to see if it has been overwritten. A heuristic is used to
1236 determine if a function needs stack protectors or not.<br>
1237<br>
1238 If a function that has an <tt>ssp</tt> attribute is inlined into a
1239 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1240 function will have an <tt>ssp</tt> attribute.</dd>
1241
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1242 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1243 <dd>This attribute indicates that the function should <em>always</em> emit a
1244 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1245 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1246<br>
1247 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1248 function that doesn't have an <tt>sspreq</tt> attribute or which has
1249 an <tt>ssp</tt> attribute, then the resulting function will have
1250 an <tt>sspreq</tt> attribute.</dd>
Rafael Espindolafbff0ec2011-07-25 15:27:59 +0000[diff] [blame]1251
1252 <dt><tt><b><a name="uwtable">uwtable</a></b></tt></dt>
1253 <dd>This attribute indicates that the ABI being targeted requires that
1254 an unwind table entry be produce for this function even if we can
1255 show that no exceptions passes by it. This is normally the case for
1256 the ELF x86-64 abi, but it can be disabled for some compilation
1257 units.</dd>
1258
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1259</dl>
1260
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1261</div>
1262
1263<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1264<h3>
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1265 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1266</h3>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1267
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1268<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1269
1270<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1271 the GCC "file scope inline asm" blocks. These blocks are internally
1272 concatenated by LLVM and treated as a single unit, but may be separated in
1273 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1274
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1275<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1276module asm "inline asm code goes here"
1277module asm "more can go here"
1278</pre>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1279
1280<p>The strings can contain any character by escaping non-printable characters.
1281 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]1282 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1283
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1284<p>The inline asm code is simply printed to the machine code .s file when
1285 assembly code is generated.</p>
1286
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1287</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1288
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1289<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1290<h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1291 <a name="datalayout">Data Layout</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1292</h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1293
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1294<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1295
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1296<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1297 data is to be laid out in memory. The syntax for the data layout is
1298 simply:</p>
1299
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1300<pre class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1301target datalayout = "<i>layout specification</i>"
1302</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1303
1304<p>The <i>layout specification</i> consists of a list of specifications
1305 separated by the minus sign character ('-'). Each specification starts with
1306 a letter and may include other information after the letter to define some
1307 aspect of the data layout. The specifications accepted are as follows:</p>
1308
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1309<dl>
1310 <dt><tt>E</tt></dt>
1311 <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]1312 bits with the most significance have the lowest address location.</dd>
1313
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1314 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1315 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1316 the bits with the least significance have the lowest address
1317 location.</dd>
1318
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1319 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1320 <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]1321 <i>preferred</i> alignments. All sizes are in bits. Specifying
1322 the <i>pref</i> alignment is optional. If omitted, the
1323 preceding <tt>:</tt> should be omitted too.</dd>
1324
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1325 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1326 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1327 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1328
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1329 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1330 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1331 <i>size</i>.</dd>
1332
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1333 <dt><tt>f<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 floating point type of a given bit
Dale Johannesen9d8d2212010-05-28 18:54:47 +0000[diff] [blame]1335 <i>size</i>. Only values of <i>size</i> that are supported by the target
1336 will work. 32 (float) and 64 (double) are supported on all targets;
1337 80 or 128 (different flavors of long double) are also supported on some
1338 targets.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1339
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1340 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1341 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1342 <i>size</i>.</dd>
1343
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1344 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1345 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1346 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1347
1348 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1349 <dd>This specifies a set of native integer widths for the target CPU
1350 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1351 "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]1352 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1353 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1354</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1355
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1356<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]1357 default set of specifications which are then (possibly) overridden by the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1358 specifications in the <tt>datalayout</tt> keyword. The default specifications
1359 are given in this list:</p>
1360
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1361<ul>
1362 <li><tt>E</tt> - big endian</li>
Dan Gohmanfdf2e8c2010-02-23 02:44:03 +0000[diff] [blame]1363 <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]1364 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1365 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1366 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1367 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1368 <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]1369 alignment of 64-bits</li>
1370 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1371 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1372 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1373 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1374 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1375 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1376</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1377
1378<p>When LLVM is determining the alignment for a given type, it uses the
1379 following rules:</p>
1380
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1381<ol>
1382 <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]1383 specification is used.</li>
1384
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1385 <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]1386 smallest integer type that is larger than the bitwidth of the sought type
1387 is used. If none of the specifications are larger than the bitwidth then
1388 the the largest integer type is used. For example, given the default
1389 specifications above, the i7 type will use the alignment of i8 (next
1390 largest) while both i65 and i256 will use the alignment of i64 (largest
1391 specified).</li>
1392
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1393 <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]1394 largest vector type that is smaller than the sought vector type will be
1395 used as a fall back. This happens because &lt;128 x double&gt; can be
1396 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1397</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1398
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1399</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1400
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1401<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1402<h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1403 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1404</h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1405
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1406<div>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1407
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1408<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1409with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1410is undefined. Pointer values are associated with address ranges
1411according to the following rules:</p>
1412
1413<ul>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1414 <li>A pointer value is associated with the addresses associated with
1415 any value it is <i>based</i> on.
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1416 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1417 range of the variable's storage.</li>
1418 <li>The result value of an allocation instruction is associated with
1419 the address range of the allocated storage.</li>
1420 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1421 no address.</li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1422 <li>An integer constant other than zero or a pointer value returned
1423 from a function not defined within LLVM may be associated with address
1424 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1425 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1426 allocated by mechanisms provided by LLVM.</li>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1427</ul>
1428
1429<p>A pointer value is <i>based</i> on another pointer value according
1430 to the following rules:</p>
1431
1432<ul>
1433 <li>A pointer value formed from a
1434 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1435 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1436 <li>The result value of a
1437 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1438 of the <tt>bitcast</tt>.</li>
1439 <li>A pointer value formed by an
1440 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1441 pointer values that contribute (directly or indirectly) to the
1442 computation of the pointer's value.</li>
1443 <li>The "<i>based</i> on" relationship is transitive.</li>
1444</ul>
1445
1446<p>Note that this definition of <i>"based"</i> is intentionally
1447 similar to the definition of <i>"based"</i> in C99, though it is
1448 slightly weaker.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1449
1450<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1451<tt><a href="#i_load">load</a></tt> merely indicates the size and
1452alignment of the memory from which to load, as well as the
Dan Gohmanc22c0f32010-06-17 19:23:50 +0000[diff] [blame]1453interpretation of the value. The first operand type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1454<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1455and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1456
1457<p>Consequently, type-based alias analysis, aka TBAA, aka
1458<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1459LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1460additional information which specialized optimization passes may use
1461to implement type-based alias analysis.</p>
1462
1463</div>
1464
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1465<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1466<h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1467 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1468</h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1469
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1470<div>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1471
1472<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1473href="#i_store"><tt>store</tt></a>s, and <a
1474href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1475The optimizers must not change the number of volatile operations or change their
1476order of execution relative to other volatile operations. The optimizers
1477<i>may</i> change the order of volatile operations relative to non-volatile
1478operations. This is not Java's "volatile" and has no cross-thread
1479synchronization behavior.</p>
1480
1481</div>
1482
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1483<!-- ======================================================================= -->
1484<h3>
1485 <a name="memmodel">Memory Model for Concurrent Operations</a>
1486</h3>
1487
1488<div>
1489
1490<p>The LLVM IR does not define any way to start parallel threads of execution
1491or to register signal handlers. Nonetheless, there are platform-specific
1492ways to create them, and we define LLVM IR's behavior in their presence. This
1493model is inspired by the C++0x memory model.</p>
1494
1495<p>We define a <i>happens-before</i> partial order as the least partial order
1496that</p>
1497<ul>
1498 <li>Is a superset of single-thread program order, and</li>
1499 <li>When a <i>synchronizes-with</i> <tt>b</tt>, includes an edge from
1500 <tt>a</tt> to <tt>b</tt>. <i>Synchronizes-with</i> pairs are introduced
1501 by platform-specific techniques, like pthread locks, thread
1502 creation, thread joining, etc., and by the atomic operations described
1503 in the <a href="#int_atomics">Atomic intrinsics</a> section.</li>
1504</ul>
1505
1506<p>Note that program order does not introduce <i>happens-before</i> edges
1507between a thread and signals executing inside that thread.</p>
1508
1509<p>Every (defined) read operation (load instructions, memcpy, atomic
1510loads/read-modify-writes, etc.) <var>R</var> reads a series of bytes written by
1511(defined) write operations (store instructions, atomic
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1512stores/read-modify-writes, memcpy, etc.). For the purposes of this section,
1513initialized globals are considered to have a write of the initializer which is
1514atomic and happens before any other read or write of the memory in question.
1515For each byte of a read <var>R</var>, <var>R<sub>byte</sub></var> may see
1516any write to the same byte, except:</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1517
1518<ul>
1519 <li>If <var>write<sub>1</sub></var> happens before
1520 <var>write<sub>2</sub></var>, and <var>write<sub>2</sub></var> happens
1521 before <var>R<sub>byte</sub></var>, then <var>R<sub>byte</sub></var>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1522 does not see <var>write<sub>1</sub></var>.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1523 <li>If <var>R<sub>byte</sub></var> happens before <var>write<sub>3</var>,
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1524 then <var>R<sub>byte</sub></var> does not see
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1525 <var>write<sub>3</sub></var>.
1526</ul>
1527
1528<p>Given that definition, <var>R<sub>byte</sub></var> is defined as follows:
1529<ul>
1530 <li>If there is no write to the same byte that happens before
1531 <var>R<sub>byte</sub></var>, <var>R<sub>byte</sub></var> returns
1532 <tt>undef</tt> for that byte.
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1533 <li>Otherwise, if <var>R<sub>byte</sub></var> may see exactly one write,
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1534 <var>R<sub>byte</sub></var> returns the value written by that
1535 write.</li>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1536 <li>Otherwise, if <var>R</var> is atomic, and all the writes
1537 <var>R<sub>byte</sub></var> may see are atomic, it chooses one of the
1538 values written. See the <a href="#int_atomics">Atomic intrinsics</a>
1539 section for additional guarantees on how the choice is made.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1540 <li>Otherwise <var>R<sub>byte</sub></var> returns <tt>undef</tt>.</li>
1541</ul>
1542
1543<p><var>R</var> returns the value composed of the series of bytes it read.
1544This implies that some bytes within the value may be <tt>undef</tt>
1545<b>without</b> the entire value being <tt>undef</tt>. Note that this only
1546defines the semantics of the operation; it doesn't mean that targets will
1547emit more than one instruction to read the series of bytes.</p>
1548
1549<p>Note that in cases where none of the atomic intrinsics are used, this model
1550places only one restriction on IR transformations on top of what is required
1551for single-threaded execution: introducing a store to a byte which might not
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1552otherwise be stored to can introduce undefined behavior. (Specifically, in
1553the case where another thread might write to and read from an address,
1554introducing a store can change a load that may see exactly one write into
1555a load that may see multiple writes.)</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1556
1557<!-- FIXME: This model assumes all targets where concurrency is relevant have
1558a byte-size store which doesn't affect adjacent bytes. As far as I can tell,
1559none of the backends currently in the tree fall into this category; however,
1560there might be targets which care. If there are, we want a paragraph
1561like the following:
1562
1563Targets may specify that stores narrower than a certain width are not
1564available; on such a target, for the purposes of this model, treat any
1565non-atomic write with an alignment or width less than the minimum width
1566as if it writes to the relevant surrounding bytes.
1567-->
1568
1569</div>
1570
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1571</div>
1572
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1573<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1574<h2><a name="typesystem">Type System</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1575<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1576
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1577<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1578
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1579<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1580 intermediate representation. Being typed enables a number of optimizations
1581 to be performed on the intermediate representation directly, without having
1582 to do extra analyses on the side before the transformation. A strong type
1583 system makes it easier to read the generated code and enables novel analyses
1584 and transformations that are not feasible to perform on normal three address
1585 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1586
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1587<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1588<h3>
1589 <a name="t_classifications">Type Classifications</a>
1590</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1591
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1592<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1593
1594<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1595
1596<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1597 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1598 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1599 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1600 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1601 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1602 </tr>
1603 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1604 <td><a href="#t_floating">floating point</a></td>
1605 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1606 </tr>
1607 <tr>
1608 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1609 <td><a href="#t_integer">integer</a>,
1610 <a href="#t_floating">floating point</a>,
1611 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1612 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1613 <a href="#t_struct">structure</a>,
1614 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1615 <a href="#t_label">label</a>,
1616 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1617 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1618 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1619 <tr>
1620 <td><a href="#t_primitive">primitive</a></td>
1621 <td><a href="#t_label">label</a>,
1622 <a href="#t_void">void</a>,
Tobias Grosser05387292010-12-28 20:29:31 +0000[diff] [blame]1623 <a href="#t_integer">integer</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1624 <a href="#t_floating">floating point</a>,
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1625 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1626 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1627 </tr>
1628 <tr>
1629 <td><a href="#t_derived">derived</a></td>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1630 <td><a href="#t_array">array</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1631 <a href="#t_function">function</a>,
1632 <a href="#t_pointer">pointer</a>,
1633 <a href="#t_struct">structure</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1634 <a href="#t_vector">vector</a>,
1635 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1636 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1637 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1638 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1639</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1640
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1641<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1642 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1643 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1644
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1645</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1646
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1647<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1648<h3>
1649 <a name="t_primitive">Primitive Types</a>
1650</h3>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1651
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1652<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1653
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1654<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1655 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1656
1657<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1658<h4>
1659 <a name="t_integer">Integer Type</a>
1660</h4>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1661
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1662<div>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1663
1664<h5>Overview:</h5>
1665<p>The integer type is a very simple type that simply specifies an arbitrary
1666 bit width for the integer type desired. Any bit width from 1 bit to
1667 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1668
1669<h5>Syntax:</h5>
1670<pre>
1671 iN
1672</pre>
1673
1674<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1675 value.</p>
1676
1677<h5>Examples:</h5>
1678<table class="layout">
1679 <tr class="layout">
1680 <td class="left"><tt>i1</tt></td>
1681 <td class="left">a single-bit integer.</td>
1682 </tr>
1683 <tr class="layout">
1684 <td class="left"><tt>i32</tt></td>
1685 <td class="left">a 32-bit integer.</td>
1686 </tr>
1687 <tr class="layout">
1688 <td class="left"><tt>i1942652</tt></td>
1689 <td class="left">a really big integer of over 1 million bits.</td>
1690 </tr>
1691</table>
1692
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1693</div>
1694
1695<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1696<h4>
1697 <a name="t_floating">Floating Point Types</a>
1698</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1699
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1700<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1701
1702<table>
1703 <tbody>
1704 <tr><th>Type</th><th>Description</th></tr>
1705 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1706 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1707 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1708 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1709 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1710 </tbody>
1711</table>
1712
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1713</div>
1714
1715<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1716<h4>
1717 <a name="t_x86mmx">X86mmx Type</a>
1718</h4>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1719
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1720<div>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1721
1722<h5>Overview:</h5>
1723<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>
1724
1725<h5>Syntax:</h5>
1726<pre>
Dale Johannesen473a8c82010-10-01 01:07:02 +0000[diff] [blame]1727 x86mmx
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1728</pre>
1729
1730</div>
1731
1732<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1733<h4>
1734 <a name="t_void">Void Type</a>
1735</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1736
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1737<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1738
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1739<h5>Overview:</h5>
1740<p>The void type does not represent any value and has no size.</p>
1741
1742<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1743<pre>
1744 void
1745</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1746
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1747</div>
1748
1749<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1750<h4>
1751 <a name="t_label">Label Type</a>
1752</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1753
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1754<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1755
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1756<h5>Overview:</h5>
1757<p>The label type represents code labels.</p>
1758
1759<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1760<pre>
1761 label
1762</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1763
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1764</div>
1765
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1766<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1767<h4>
1768 <a name="t_metadata">Metadata Type</a>
1769</h4>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1770
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1771<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1772
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1773<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1774<p>The metadata type represents embedded metadata. No derived types may be
1775 created from metadata except for <a href="#t_function">function</a>
1776 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1777
1778<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1779<pre>
1780 metadata
1781</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1782
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1783</div>
1784
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1785</div>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1786
1787<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1788<h3>
1789 <a name="t_derived">Derived Types</a>
1790</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1791
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1792<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1793
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1794<p>The real power in LLVM comes from the derived types in the system. This is
1795 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1796 useful types. Each of these types contain one or more element types which
1797 may be a primitive type, or another derived type. For example, it is
1798 possible to have a two dimensional array, using an array as the element type
1799 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1800
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1801</div>
1802
1803
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1804<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1805<h4>
1806 <a name="t_aggregate">Aggregate Types</a>
1807</h4>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1808
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1809<div>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1810
1811<p>Aggregate Types are a subset of derived types that can contain multiple
1812 member types. <a href="#t_array">Arrays</a>,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]1813 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1814 aggregate types.</p>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1815
1816</div>
1817
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1818<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1819<h4>
1820 <a name="t_array">Array Type</a>
1821</h4>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1822
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1823<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1824
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1825<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1826<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1827 sequentially in memory. The array type requires a size (number of elements)
1828 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1829
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1830<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1831<pre>
1832 [&lt;# elements&gt; x &lt;elementtype&gt;]
1833</pre>
1834
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1835<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1836 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1837
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1838<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1839<table class="layout">
1840 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1841 <td class="left"><tt>[40 x i32]</tt></td>
1842 <td class="left">Array of 40 32-bit integer values.</td>
1843 </tr>
1844 <tr class="layout">
1845 <td class="left"><tt>[41 x i32]</tt></td>
1846 <td class="left">Array of 41 32-bit integer values.</td>
1847 </tr>
1848 <tr class="layout">
1849 <td class="left"><tt>[4 x i8]</tt></td>
1850 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1851 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1852</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1853<p>Here are some examples of multidimensional arrays:</p>
1854<table class="layout">
1855 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1856 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1857 <td class="left">3x4 array of 32-bit integer values.</td>
1858 </tr>
1859 <tr class="layout">
1860 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1861 <td class="left">12x10 array of single precision floating point values.</td>
1862 </tr>
1863 <tr class="layout">
1864 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1865 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1866 </tr>
1867</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1868
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1869<p>There is no restriction on indexing beyond the end of the array implied by
1870 a static type (though there are restrictions on indexing beyond the bounds
1871 of an allocated object in some cases). This means that single-dimension
1872 'variable sized array' addressing can be implemented in LLVM with a zero
1873 length array type. An implementation of 'pascal style arrays' in LLVM could
1874 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1875
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1876</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1877
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1878<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1879<h4>
1880 <a name="t_function">Function Type</a>
1881</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1882
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1883<div>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1884
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1885<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1886<p>The function type can be thought of as a function signature. It consists of
1887 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]1888 function type is a first class type or a void type.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1889
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1890<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1891<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1892 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1893</pre>
1894
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1895<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]1896 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1897 which indicates that the function takes a variable number of arguments.
1898 Variable argument functions can access their arguments with
1899 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1900 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1901 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1902
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1903<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1904<table class="layout">
1905 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1906 <td class="left"><tt>i32 (i32)</tt></td>
1907 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1908 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1909 </tr><tr class="layout">
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1910 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1911 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1912 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1913 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1914 returning <tt>float</tt>.
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1915 </td>
1916 </tr><tr class="layout">
1917 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1918 <td class="left">A vararg function that takes at least one
1919 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1920 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1921 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1922 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1923 </tr><tr class="layout">
1924 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1925 <td class="left">A function taking an <tt>i32</tt>, returning a
1926 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1927 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1928 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1929</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1930
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1931</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1932
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1933<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1934<h4>
1935 <a name="t_struct">Structure Type</a>
1936</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1937
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1938<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1939
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1940<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1941<p>The structure type is used to represent a collection of data members together
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1942 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]1943
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]1944<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1945 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1946 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1947 Structures in registers are accessed using the
1948 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1949 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1950
1951<p>Structures may optionally be "packed" structures, which indicate that the
1952 alignment of the struct is one byte, and that there is no padding between
1953 the elements. In non-packed structs, padding between field types is defined
1954 by the target data string to match the underlying processor.</p>
1955
1956<p>Structures can either be "anonymous" or "named". An anonymous structure is
1957 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) and a named types
1958 are always defined at the top level with a name. Anonmyous types are uniqued
1959 by their contents and can never be recursive since there is no way to write
1960 one. Named types can be recursive.
1961</p>
1962
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1963<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1964<pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1965 %T1 = type { &lt;type list&gt; } <i>; Named normal struct type</i>
1966 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Named packed struct type</i>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1967</pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1968
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1969<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1970<table class="layout">
1971 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1972 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1973 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1974 </tr>
1975 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1976 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1977 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1978 second element is a <a href="#t_pointer">pointer</a> to a
1979 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1980 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1981 </tr>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1982 <tr class="layout">
1983 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
1984 <td class="left">A packed struct known to be 5 bytes in size.</td>
1985 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1986</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1987
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1988</div>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1989
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1990<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1991<h4>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]1992 <a name="t_opaque">Opaque Structure Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1993</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1994
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1995<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1996
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1997<h5>Overview:</h5>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]1998<p>Opaque structure types are used to represent named structure types that do
1999 not have a body specified. This corresponds (for example) to the C notion of
2000 a forward declared structure.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2001
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2002<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2003<pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2004 %X = type opaque
2005 %52 = type opaque
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2006</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2007
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2008<h5>Examples:</h5>
2009<table class="layout">
2010 <tr class="layout">
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2011 <td class="left"><tt>opaque</tt></td>
2012 <td class="left">An opaque type.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2013 </tr>
2014</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2015
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2016</div>
2017
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2018
2019
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2020<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2021<h4>
2022 <a name="t_pointer">Pointer Type</a>
2023</h4>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2024
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2025<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2026
2027<h5>Overview:</h5>
Dan Gohmanff3ef322010-02-25 16:50:07 +0000[diff] [blame]2028<p>The pointer type is used to specify memory locations.
2029 Pointers are commonly used to reference objects in memory.</p>
2030
2031<p>Pointer types may have an optional address space attribute defining the
2032 numbered address space where the pointed-to object resides. The default
2033 address space is number zero. The semantics of non-zero address
2034 spaces are target-specific.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2035
2036<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
2037 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2038
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2039<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2040<pre>
2041 &lt;type&gt; *
2042</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2043
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2044<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2045<table class="layout">
2046 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2047 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2048 <td class="left">A <a href="#t_pointer">pointer</a> to <a
2049 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
2050 </tr>
2051 <tr class="layout">
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]2052 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2053 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2054 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2055 <tt>i32</tt>.</td>
2056 </tr>
2057 <tr class="layout">
2058 <td class="left"><tt>i32 addrspace(5)*</tt></td>
2059 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
2060 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2061 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2062</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2063
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2064</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2065
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2066<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2067<h4>
2068 <a name="t_vector">Vector Type</a>
2069</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2070
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2071<div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2072
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2073<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2074<p>A vector type is a simple derived type that represents a vector of elements.
2075 Vector types are used when multiple primitive data are operated in parallel
2076 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]2077 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2078 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2079
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2080<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2081<pre>
2082 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2083</pre>
2084
Chris Lattner7d2e7be2010-10-10 18:20:35 +0000[diff] [blame]2085<p>The number of elements is a constant integer value larger than 0; elementtype
2086 may be any integer or floating point type. Vectors of size zero are not
2087 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2088
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2089<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2090<table class="layout">
2091 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2092 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
2093 <td class="left">Vector of 4 32-bit integer values.</td>
2094 </tr>
2095 <tr class="layout">
2096 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
2097 <td class="left">Vector of 8 32-bit floating-point values.</td>
2098 </tr>
2099 <tr class="layout">
2100 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2101 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2102 </tr>
2103</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2104
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2105</div>
2106
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2107<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2108<h2><a name="constants">Constants</a></h2>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2109<!-- *********************************************************************** -->
2110
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2111<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2112
2113<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2114 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2115
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2116<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2117<h3>
2118 <a name="simpleconstants">Simple Constants</a>
2119</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2120
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2121<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2122
2123<dl>
2124 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2125 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]2126 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2127
2128 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2129 <dd>Standard integers (such as '4') are constants of
2130 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2131 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2132
2133 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2134 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2135 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2136 notation (see below). The assembler requires the exact decimal value of a
2137 floating-point constant. For example, the assembler accepts 1.25 but
2138 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2139 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2140
2141 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2142 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2143 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2144</dl>
2145
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2146<p>The one non-intuitive notation for constants is the hexadecimal form of
2147 floating point constants. For example, the form '<tt>double
2148 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2149 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2150 constants are required (and the only time that they are generated by the
2151 disassembler) is when a floating point constant must be emitted but it cannot
2152 be represented as a decimal floating point number in a reasonable number of
2153 digits. For example, NaN's, infinities, and other special values are
2154 represented in their IEEE hexadecimal format so that assembly and disassembly
2155 do not cause any bits to change in the constants.</p>
2156
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]2157<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2158 represented using the 16-digit form shown above (which matches the IEEE754
2159 representation for double); float values must, however, be exactly
2160 representable as IEE754 single precision. Hexadecimal format is always used
2161 for long double, and there are three forms of long double. The 80-bit format
2162 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2163 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2164 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2165 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2166 currently supported target uses this format. Long doubles will only work if
2167 they match the long double format on your target. All hexadecimal formats
2168 are big-endian (sign bit at the left).</p>
2169
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]2170<p>There are no constants of type x86mmx.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2171</div>
2172
2173<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2174<h3>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2175<a name="aggregateconstants"></a> <!-- old anchor -->
2176<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2177</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2178
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2179<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2180
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2181<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2182 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2183
2184<dl>
2185 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2186 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2187 type definitions (a comma separated list of elements, surrounded by braces
2188 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2189 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2190 Structure constants must have <a href="#t_struct">structure type</a>, and
2191 the number and types of elements must match those specified by the
2192 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2193
2194 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2195 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2196 definitions (a comma separated list of elements, surrounded by square
2197 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2198 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2199 the number and types of elements must match those specified by the
2200 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2201
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2202 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2203 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2204 definitions (a comma separated list of elements, surrounded by
2205 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2206 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2207 have <a href="#t_vector">vector type</a>, and the number and types of
2208 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2209
2210 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2211 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2212 value to zero of <em>any</em> type, including scalar and
2213 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2214 This is often used to avoid having to print large zero initializers
2215 (e.g. for large arrays) and is always exactly equivalent to using explicit
2216 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2217
2218 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2219 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2220 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2221 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2222 be interpreted as part of the instruction stream, metadata is a place to
2223 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2224</dl>
2225
2226</div>
2227
2228<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2229<h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2230 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2231</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2232
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2233<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2234
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2235<p>The addresses of <a href="#globalvars">global variables</a>
2236 and <a href="#functionstructure">functions</a> are always implicitly valid
2237 (link-time) constants. These constants are explicitly referenced when
2238 the <a href="#identifiers">identifier for the global</a> is used and always
2239 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2240 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2241
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2242<pre class="doc_code">
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2243@X = global i32 17
2244@Y = global i32 42
2245@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2246</pre>
2247
2248</div>
2249
2250<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2251<h3>
2252 <a name="undefvalues">Undefined Values</a>
2253</h3>
2254
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2255<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2256
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2257<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]2258 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2259 Undefined values may be of any type (other than '<tt>label</tt>'
2260 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2261
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2262<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2263 program is well defined no matter what value is used. This gives the
2264 compiler more freedom to optimize. Here are some examples of (potentially
2265 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2266
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2267
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2268<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2269 %A = add %X, undef
2270 %B = sub %X, undef
2271 %C = xor %X, undef
2272Safe:
2273 %A = undef
2274 %B = undef
2275 %C = undef
2276</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2277
2278<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]2279 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]2280
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2281<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2282 %A = or %X, undef
2283 %B = and %X, undef
2284Safe:
2285 %A = -1
2286 %B = 0
2287Unsafe:
2288 %A = undef
2289 %B = undef
2290</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2291
2292<p>These logical operations have bits that are not always affected by the input.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2293 For example, if <tt>%X</tt> has a zero bit, then the output of the
2294 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2295 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2296 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2297 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2298 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2299 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2300 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2301
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2302<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2303 %A = select undef, %X, %Y
2304 %B = select undef, 42, %Y
2305 %C = select %X, %Y, undef
2306Safe:
2307 %A = %X (or %Y)
2308 %B = 42 (or %Y)
2309 %C = %Y
2310Unsafe:
2311 %A = undef
2312 %B = undef
2313 %C = undef
2314</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2315
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2316<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2317 branch) conditions can go <em>either way</em>, but they have to come from one
2318 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2319 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2320 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2321 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2322 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2323 eliminated.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2324
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2325<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2326 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2327
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2328 %B = undef
2329 %C = xor %B, %B
2330
2331 %D = undef
2332 %E = icmp lt %D, 4
2333 %F = icmp gte %D, 4
2334
2335Safe:
2336 %A = undef
2337 %B = undef
2338 %C = undef
2339 %D = undef
2340 %E = undef
2341 %F = undef
2342</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2343
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2344<p>This example points out that two '<tt>undef</tt>' operands are not
2345 necessarily the same. This can be surprising to people (and also matches C
2346 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2347 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2348 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2349 its value over its "live range". This is true because the variable doesn't
2350 actually <em>have a live range</em>. Instead, the value is logically read
2351 from arbitrary registers that happen to be around when needed, so the value
2352 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2353 need to have the same semantics or the core LLVM "replace all uses with"
2354 concept would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2355
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2356<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2357 %A = fdiv undef, %X
2358 %B = fdiv %X, undef
2359Safe:
2360 %A = undef
2361b: unreachable
2362</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2363
2364<p>These examples show the crucial difference between an <em>undefined
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2365 value</em> and <em>undefined behavior</em>. An undefined value (like
2366 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2367 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2368 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2369 defined on SNaN's. However, in the second example, we can make a more
2370 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2371 arbitrary value, we are allowed to assume that it could be zero. Since a
2372 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2373 the operation does not execute at all. This allows us to delete the divide and
2374 all code after it. Because the undefined operation "can't happen", the
2375 optimizer can assume that it occurs in dead code.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2376
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2377<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2378a: store undef -> %X
2379b: store %X -> undef
2380Safe:
2381a: &lt;deleted&gt;
2382b: unreachable
2383</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2384
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2385<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2386 undefined value can be assumed to not have any effect; we can assume that the
2387 value is overwritten with bits that happen to match what was already there.
2388 However, a store <em>to</em> an undefined location could clobber arbitrary
2389 memory, therefore, it has undefined behavior.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2390
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2391</div>
2392
2393<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2394<h3>
2395 <a name="trapvalues">Trap Values</a>
2396</h3>
2397
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2398<div>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2399
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2400<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2401 instead of representing an unspecified bit pattern, they represent the
2402 fact that an instruction or constant expression which cannot evoke side
2403 effects has nevertheless detected a condition which results in undefined
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2404 behavior.</p>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2405
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2406<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]2407 only exist when produced by operations such as
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2408 <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]2409
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2410<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2411
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2412<ul>
2413<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2414 their operands.</li>
2415
2416<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2417 to their dynamic predecessor basic block.</li>
2418
2419<li>Function arguments depend on the corresponding actual argument values in
2420 the dynamic callers of their functions.</li>
2421
2422<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2423 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2424 control back to them.</li>
2425
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2426<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2427 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2428 or exception-throwing call instructions that dynamically transfer control
2429 back to them.</li>
2430
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2431<li>Non-volatile loads and stores depend on the most recent stores to all of the
2432 referenced memory addresses, following the order in the IR
2433 (including loads and stores implied by intrinsics such as
2434 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2435
Dan Gohman7c24ff12010-05-03 14:59:34 +0000[diff] [blame]2436<!-- TODO: In the case of multiple threads, this only applies if the store
2437 "happens-before" the load or store. -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2438
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2439<!-- TODO: floating-point exception state -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2440
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2441<li>An instruction with externally visible side effects depends on the most
2442 recent preceding instruction with externally visible side effects, following
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]2443 the order in the IR. (This includes
2444 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2445
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2446<li>An instruction <i>control-depends</i> on a
2447 <a href="#terminators">terminator instruction</a>
2448 if the terminator instruction has multiple successors and the instruction
2449 is always executed when control transfers to one of the successors, and
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2450 may not be executed when control is transferred to another.</li>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2451
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2452<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2453 instruction if the set of instructions it otherwise depends on would be
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2454 different if the terminator had transferred control to a different
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2455 successor.</li>
2456
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2457<li>Dependence is transitive.</li>
2458
2459</ul>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2460
2461<p>Whenever a trap value is generated, all values which depend on it evaluate
2462 to trap. If they have side effects, the evoke their side effects as if each
2463 operand with a trap value were undef. If they have externally-visible side
2464 effects, the behavior is undefined.</p>
2465
2466<p>Here are some examples:</p>
Dan Gohmanc30f6e12010-04-26 20:54:53 +0000[diff] [blame]2467
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2468<pre class="doc_code">
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2469entry:
2470 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2471 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2472 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2473 store i32 0, i32* %trap_yet_again ; undefined behavior
2474
2475 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2476 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2477
2478 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2479
2480 %narrowaddr = bitcast i32* @g to i16*
2481 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2482 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2483 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2484
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2485 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2486 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2487
2488true:
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2489 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2490 ; it has undefined behavior.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2491 br label %end
2492
2493end:
2494 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2495 ; Both edges into this PHI are
2496 ; control-dependent on %cmp, so this
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2497 ; always results in a trap value.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2498
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2499 volatile store i32 0, i32* @g ; This would depend on the store in %true
2500 ; if %cmp is true, or the store in %entry
2501 ; otherwise, so this is undefined behavior.
2502
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2503 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2504 ; The same branch again, but this time the
2505 ; true block doesn't have side effects.
2506
2507second_true:
2508 ; No side effects!
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2509 ret void
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2510
2511second_end:
2512 volatile store i32 0, i32* @g ; This time, the instruction always depends
2513 ; on the store in %end. Also, it is
2514 ; control-equivalent to %end, so this is
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2515 ; well-defined (again, ignoring earlier
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2516 ; undefined behavior in this example).
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2517</pre>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2518
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2519</div>
2520
2521<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2522<h3>
2523 <a name="blockaddress">Addresses of Basic Blocks</a>
2524</h3>
2525
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2526<div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2527
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2528<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2529
2530<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2531 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2532 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2533
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2534<p>This value only has defined behavior when used as an operand to the
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2535 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2536 comparisons against null. Pointer equality tests between labels addresses
2537 results in undefined behavior &mdash; though, again, comparison against null
2538 is ok, and no label is equal to the null pointer. This may be passed around
2539 as an opaque pointer sized value as long as the bits are not inspected. This
2540 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2541 long as the original value is reconstituted before the <tt>indirectbr</tt>
2542 instruction.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2543
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2544<p>Finally, some targets may provide defined semantics when using the value as
2545 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2546
2547</div>
2548
2549
2550<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2551<h3>
2552 <a name="constantexprs">Constant Expressions</a>
2553</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2554
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2555<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2556
2557<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2558 to be used as constants. Constant expressions may be of
2559 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2560 operation that does not have side effects (e.g. load and call are not
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2561 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2562
2563<dl>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2564 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2565 <dd>Truncate a constant to another type. The bit size of CST must be larger
2566 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2567
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2568 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2569 <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]2570 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2571
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2572 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2573 <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]2574 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2575
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2576 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2577 <dd>Truncate a floating point constant to another floating point type. The
2578 size of CST must be larger than the size of TYPE. Both types must be
2579 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2580
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2581 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2582 <dd>Floating point extend a constant to another type. The size of CST must be
2583 smaller or equal to the size of TYPE. Both types must be floating
2584 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2585
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2586 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2587 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2588 constant. TYPE must be a scalar or vector integer type. CST must be of
2589 scalar or vector floating point type. Both CST and TYPE must be scalars,
2590 or vectors of the same number of elements. If the value won't fit in the
2591 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2592
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2593 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2594 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2595 constant. TYPE must be a scalar or vector integer type. CST must be of
2596 scalar or vector floating point type. Both CST and TYPE must be scalars,
2597 or vectors of the same number of elements. If the value won't fit in the
2598 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2599
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2600 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2601 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2602 constant. TYPE must be a scalar or vector floating point type. CST must be
2603 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2604 vectors of the same number of elements. If the value won't fit in the
2605 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2606
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2607 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2608 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2609 constant. TYPE must be a scalar or vector floating point type. CST must be
2610 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2611 vectors of the same number of elements. If the value won't fit in the
2612 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2613
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2614 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2615 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2616 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2617 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2618 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2619
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2620 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2621 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2622 type. CST must be of integer type. The CST value is zero extended,
2623 truncated, or unchanged to make it fit in a pointer size. This one is
2624 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2625
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2626 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2627 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2628 are the same as those for the <a href="#i_bitcast">bitcast
2629 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2630
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2631 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2632 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2633 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2634 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2635 instruction, the index list may have zero or more indexes, which are
2636 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2637
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2638 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2639 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2640
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2641 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2642 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2643
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2644 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2645 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2646
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2647 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2648 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2649 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2650
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2651 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2652 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2653 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2654
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2655 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2656 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2657 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2658
Nick Lewycky9e130ce2010-05-29 06:44:15 +0000[diff] [blame]2659 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2660 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2661 constants. The index list is interpreted in a similar manner as indices in
2662 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2663 index value must be specified.</dd>
2664
2665 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2666 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2667 constants. The index list is interpreted in a similar manner as indices in
2668 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2669 index value must be specified.</dd>
2670
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2671 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2672 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2673 be any of the <a href="#binaryops">binary</a>
2674 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2675 on operands are the same as those for the corresponding instruction
2676 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2677</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2678
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2679</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2680
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2681</div>
2682
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2683<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2684<h2><a name="othervalues">Other Values</a></h2>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2685<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2686<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2687<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2688<h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2689<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2690</h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2691
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2692<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2693
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2694<p>LLVM supports inline assembler expressions (as opposed
2695 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2696 a special value. This value represents the inline assembler as a string
2697 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2698 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2699 expression has side effects, and a flag indicating whether the function
2700 containing the asm needs to align its stack conservatively. An example
2701 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2702
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2703<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2704i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2705</pre>
2706
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2707<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2708 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2709 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2710
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2711<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2712%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]2713</pre>
2714
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2715<p>Inline asms with side effects not visible in the constraint list must be
2716 marked as having side effects. This is done through the use of the
2717 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2718
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2719<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2720call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2721</pre>
2722
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2723<p>In some cases inline asms will contain code that will not work unless the
2724 stack is aligned in some way, such as calls or SSE instructions on x86,
2725 yet will not contain code that does that alignment within the asm.
2726 The compiler should make conservative assumptions about what the asm might
2727 contain and should generate its usual stack alignment code in the prologue
2728 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2729
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2730<pre class="doc_code">
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2731call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2732</pre>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2733
2734<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2735 first.</p>
2736
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2737<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2738 documented here. Constraints on what can be done (e.g. duplication, moving,
2739 etc need to be documented). This is probably best done by reference to
2740 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2741
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2742<h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2743<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2744</h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2745
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2746<div>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2747
2748<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2749 attached to it that contains a list of constant integers. If present, the
2750 code generator will use the integer as the location cookie value when report
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2751 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]2752 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2753 source code that produced it. For example:</p>
2754
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2755<pre class="doc_code">
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2756call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2757...
2758!42 = !{ i32 1234567 }
2759</pre>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2760
2761<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]2762 IR. If the MDNode contains multiple constants, the code generator will use
2763 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]2764
2765</div>
2766
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2767</div>
2768
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2769<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2770<h3>
2771 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2772</h3>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2773
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2774<div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2775
2776<p>LLVM IR allows metadata to be attached to instructions in the program that
2777 can convey extra information about the code to the optimizers and code
2778 generator. One example application of metadata is source-level debug
2779 information. There are two metadata primitives: strings and nodes. All
2780 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2781 preceding exclamation point ('<tt>!</tt>').</p>
2782
2783<p>A metadata string is a string surrounded by double quotes. It can contain
2784 any character by escaping non-printable characters with "\xx" where "xx" is
2785 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2786
2787<p>Metadata nodes are represented with notation similar to structure constants
2788 (a comma separated list of elements, surrounded by braces and preceded by an
2789 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2790 10}</tt>". Metadata nodes can have any values as their operand.</p>
2791
2792<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2793 metadata nodes, which can be looked up in the module symbol table. For
2794 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2795
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2796<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2797 function is using two metadata arguments.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2798
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2799<div class="doc_code">
2800<pre>
2801call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2802</pre>
2803</div>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2804
2805<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2806 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2807
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2808<div class="doc_code">
2809<pre>
2810%indvar.next = add i64 %indvar, 1, !dbg !21
2811</pre>
2812</div>
2813
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2814</div>
2815
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2816</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2817
2818<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2819<h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2820 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2821</h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2822<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2823<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2824<p>LLVM has a number of "magic" global variables that contain data that affect
2825code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2826of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2827section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2828by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2829
2830<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2831<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2832<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2833</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2834
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2835<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2836
2837<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2838href="#linkage_appending">appending linkage</a>. This array contains a list of
2839pointers to global variables and functions which may optionally have a pointer
2840cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2841
2842<pre>
2843 @X = global i8 4
2844 @Y = global i32 123
2845
2846 @llvm.used = appending global [2 x i8*] [
2847 i8* @X,
2848 i8* bitcast (i32* @Y to i8*)
2849 ], section "llvm.metadata"
2850</pre>
2851
2852<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2853compiler, assembler, and linker are required to treat the symbol as if there is
2854a reference to the global that it cannot see. For example, if a variable has
2855internal linkage and no references other than that from the <tt>@llvm.used</tt>
2856list, it cannot be deleted. This is commonly used to represent references from
2857inline asms and other things the compiler cannot "see", and corresponds to
2858"attribute((used))" in GNU C.</p>
2859
2860<p>On some targets, the code generator must emit a directive to the assembler or
2861object file to prevent the assembler and linker from molesting the symbol.</p>
2862
2863</div>
2864
2865<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2866<h3>
2867 <a name="intg_compiler_used">
2868 The '<tt>llvm.compiler.used</tt>' Global Variable
2869 </a>
2870</h3>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2871
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2872<div>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2873
2874<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2875<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2876touching the symbol. On targets that support it, this allows an intelligent
2877linker to optimize references to the symbol without being impeded as it would be
2878by <tt>@llvm.used</tt>.</p>
2879
2880<p>This is a rare construct that should only be used in rare circumstances, and
2881should not be exposed to source languages.</p>
2882
2883</div>
2884
2885<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2886<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2887<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2888</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2889
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2890<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2891<pre>
2892%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2893@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2894</pre>
2895<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.
2896</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2897
2898</div>
2899
2900<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2901<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2902<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2903</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2904
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2905<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2906<pre>
2907%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2908@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2909</pre>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2910
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2911<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.
2912</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2913
2914</div>
2915
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2916</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2917
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2918<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2919<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2920<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2921
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2922<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2923
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2924<p>The LLVM instruction set consists of several different classifications of
2925 instructions: <a href="#terminators">terminator
2926 instructions</a>, <a href="#binaryops">binary instructions</a>,
2927 <a href="#bitwiseops">bitwise binary instructions</a>,
2928 <a href="#memoryops">memory instructions</a>, and
2929 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2930
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2931<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2932<h3>
2933 <a name="terminators">Terminator Instructions</a>
2934</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2935
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2936<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2937
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2938<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2939 in a program ends with a "Terminator" instruction, which indicates which
2940 block should be executed after the current block is finished. These
2941 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2942 control flow, not values (the one exception being the
2943 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2944
Duncan Sands83821c82010-04-15 20:35:54 +0000[diff] [blame]2945<p>There are seven different terminator instructions: the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2946 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2947 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2948 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling21c346e2009-11-02 00:25:26 +0000[diff] [blame]2949 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2950 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2951 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2952 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2953
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2954<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2955<h4>
2956 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
2957</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2958
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2959<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2960
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2961<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2962<pre>
2963 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]2964 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2965</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2966
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2967<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2968<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2969 a value) from a function back to the caller.</p>
2970
2971<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2972 value and then causes control flow, and one that just causes control flow to
2973 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2974
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2975<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2976<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2977 return value. The type of the return value must be a
2978 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2979
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2980<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2981 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2982 value or a return value with a type that does not match its type, or if it
2983 has a void return type and contains a '<tt>ret</tt>' instruction with a
2984 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2985
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2986<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2987<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2988 the calling function's context. If the caller is a
2989 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2990 instruction after the call. If the caller was an
2991 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2992 the beginning of the "normal" destination block. If the instruction returns
2993 a value, that value shall set the call or invoke instruction's return
2994 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2995
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2996<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2997<pre>
2998 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2999 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]3000 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]3001</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3002
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3003</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3004<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3005<h4>
3006 <a name="i_br">'<tt>br</tt>' Instruction</a>
3007</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3008
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3009<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3010
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3011<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3012<pre>
3013 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3014</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3015
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3016<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3017<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3018 different basic block in the current function. There are two forms of this
3019 instruction, corresponding to a conditional branch and an unconditional
3020 branch.</p>
3021
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3022<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3023<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3024 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3025 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3026 target.</p>
3027
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3028<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3029<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3030 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3031 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3032 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3033
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3034<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]3035<pre>
3036Test:
3037 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3038 br i1 %cond, label %IfEqual, label %IfUnequal
3039IfEqual:
3040 <a href="#i_ret">ret</a> i32 1
3041IfUnequal:
3042 <a href="#i_ret">ret</a> i32 0
3043</pre>
3044
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3045</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3046
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3047<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3048<h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3049 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3050</h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3051
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3052<div>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3053
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3054<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3055<pre>
3056 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3057</pre>
3058
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3059<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3060<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]3061 several different places. It is a generalization of the '<tt>br</tt>'
3062 instruction, allowing a branch to occur to one of many possible
3063 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3064
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3065<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3066<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3067 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3068 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3069 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3070
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3071<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3072<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3073 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3074 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]3075 transferred to the corresponding destination; otherwise, control flow is
3076 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3077
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3078<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3079<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3080 <tt>switch</tt> instruction, this instruction may be code generated in
3081 different ways. For example, it could be generated as a series of chained
3082 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3083
3084<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3085<pre>
3086 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3087 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3088 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3089
3090 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3091 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3092
3093 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3094 switch i32 %val, label %otherwise [ i32 0, label %onzero
3095 i32 1, label %onone
3096 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3097</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3098
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3099</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3100
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3101
3102<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3103<h4>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3104 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3105</h4>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3106
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3107<div>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3108
3109<h5>Syntax:</h5>
3110<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3111 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]3112</pre>
3113
3114<h5>Overview:</h5>
3115
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3116<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3117 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]3118 "<tt>address</tt>". Address must be derived from a <a
3119 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3120
3121<h5>Arguments:</h5>
3122
3123<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3124 rest of the arguments indicate the full set of possible destinations that the
3125 address may point to. Blocks are allowed to occur multiple times in the
3126 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3127
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3128<p>This destination list is required so that dataflow analysis has an accurate
3129 understanding of the CFG.</p>
3130
3131<h5>Semantics:</h5>
3132
3133<p>Control transfers to the block specified in the address argument. All
3134 possible destination blocks must be listed in the label list, otherwise this
3135 instruction has undefined behavior. This implies that jumps to labels
3136 defined in other functions have undefined behavior as well.</p>
3137
3138<h5>Implementation:</h5>
3139
3140<p>This is typically implemented with a jump through a register.</p>
3141
3142<h5>Example:</h5>
3143<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3144 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3145</pre>
3146
3147</div>
3148
3149
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3150<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3151<h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3152 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3153</h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3154
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3155<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3156
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3157<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3158<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3159 &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]3160 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3161</pre>
3162
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3163<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3164<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3165 function, with the possibility of control flow transfer to either the
3166 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3167 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3168 control flow will return to the "normal" label. If the callee (or any
3169 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3170 instruction, control is interrupted and continued at the dynamically nearest
3171 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3172
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3173<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3174<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3175
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3176<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3177 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3178 convention</a> the call should use. If none is specified, the call
3179 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3180
3181 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3182 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3183 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3184
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3185 <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]3186 function value being invoked. In most cases, this is a direct function
3187 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3188 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3189
3190 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3191 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3192
3193 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]3194 signature argument types and parameter attributes. All arguments must be
3195 of <a href="#t_firstclass">first class</a> type. If the function
3196 signature indicates the function accepts a variable number of arguments,
3197 the extra arguments can be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3198
3199 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3200 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3201
3202 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3203 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3204
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3205 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3206 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3207 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3208</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3209
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3210<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3211<p>This instruction is designed to operate as a standard
3212 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3213 primary difference is that it establishes an association with a label, which
3214 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3215
3216<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3217 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3218 exception. Additionally, this is important for implementation of
3219 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3220
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3221<p>For the purposes of the SSA form, the definition of the value returned by the
3222 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3223 block to the "normal" label. If the callee unwinds then no return value is
3224 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]3225
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3226<p>Note that the code generator does not yet completely support unwind, and
3227that the invoke/unwind semantics are likely to change in future versions.</p>
3228
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3229<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3230<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3231 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3232 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3233 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3234 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3235</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3236
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3237</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3238
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3239<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3240
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3241<h4>
3242 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3243</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3244
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3245<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3246
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3247<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3248<pre>
3249 unwind
3250</pre>
3251
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3252<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3253<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3254 at the first callee in the dynamic call stack which used
3255 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3256 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3257
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3258<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3259<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3260 immediately halt. The dynamic call stack is then searched for the
3261 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3262 Once found, execution continues at the "exceptional" destination block
3263 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3264 instruction in the dynamic call chain, undefined behavior results.</p>
3265
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3266<p>Note that the code generator does not yet completely support unwind, and
3267that the invoke/unwind semantics are likely to change in future versions.</p>
3268
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3269</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3270
3271<!-- _______________________________________________________________________ -->
3272
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3273<h4>
3274 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3275</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3276
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3277<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3278
3279<h5>Syntax:</h5>
3280<pre>
3281 unreachable
3282</pre>
3283
3284<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3285<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3286 instruction is used to inform the optimizer that a particular portion of the
3287 code is not reachable. This can be used to indicate that the code after a
3288 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3289
3290<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3291<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3292
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3293</div>
3294
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3295</div>
3296
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3297<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3298<h3>
3299 <a name="binaryops">Binary Operations</a>
3300</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3301
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3302<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3303
3304<p>Binary operators are used to do most of the computation in a program. They
3305 require two operands of the same type, execute an operation on them, and
3306 produce a single value. The operands might represent multiple data, as is
3307 the case with the <a href="#t_vector">vector</a> data type. The result value
3308 has the same type as its operands.</p>
3309
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3310<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3311
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3312<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3313<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3314 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3315</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3316
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3317<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3318
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3319<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3320<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3321 &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]3322 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3323 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3324 &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]3325</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3326
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3327<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3328<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3329
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3330<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3331<p>The two arguments to the '<tt>add</tt>' instruction must
3332 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3333 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3334
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3335<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3336<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3337
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3338<p>If the sum has unsigned overflow, the result returned is the mathematical
3339 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]3340
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3341<p>Because LLVM integers use a two's complement representation, this instruction
3342 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3343
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3344<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3345 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3346 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3347 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3348 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3349
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3350<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3351<pre>
3352 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3353</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3354
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3355</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3356
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3357<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3358<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3359 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3360</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3361
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3362<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3363
3364<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3365<pre>
3366 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3367</pre>
3368
3369<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3370<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3371
3372<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3373<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3374 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3375 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3376
3377<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3378<p>The value produced is the floating point sum of the two operands.</p>
3379
3380<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3381<pre>
3382 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3383</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3384
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3385</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3386
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3387<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3388<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3389 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3390</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3391
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3392<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3393
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3394<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3395<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3396 &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]3397 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3398 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3399 &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]3400</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3401
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3402<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3403<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3404 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3405
3406<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3407 '<tt>neg</tt>' instruction present in most other intermediate
3408 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3409
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3410<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3411<p>The two arguments to the '<tt>sub</tt>' instruction must
3412 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3413 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3414
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3415<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3416<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3417
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3418<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3419 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3420 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3421
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3422<p>Because LLVM integers use a two's complement representation, this instruction
3423 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3424
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3425<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3426 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3427 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3428 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3429 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3430
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3431<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3432<pre>
3433 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3434 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3435</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3436
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3437</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3438
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3439<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3440<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3441 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3442</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3443
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3444<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3445
3446<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3447<pre>
3448 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3449</pre>
3450
3451<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3452<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3453 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3454
3455<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3456 '<tt>fneg</tt>' instruction present in most other intermediate
3457 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3458
3459<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3460<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3461 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3462 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3463
3464<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3465<p>The value produced is the floating point difference of the two operands.</p>
3466
3467<h5>Example:</h5>
3468<pre>
3469 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3470 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3471</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3472
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3473</div>
3474
3475<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3476<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3477 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3478</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3479
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3480<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3481
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3482<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3483<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3484 &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]3485 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3486 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3487 &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]3488</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3489
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3490<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3491<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3492
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3493<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3494<p>The two arguments to the '<tt>mul</tt>' instruction must
3495 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3496 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3497
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3498<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3499<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3500
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3501<p>If the result of the multiplication has unsigned overflow, the result
3502 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3503 width of the result.</p>
3504
3505<p>Because LLVM integers use a two's complement representation, and the result
3506 is the same width as the operands, this instruction returns the correct
3507 result for both signed and unsigned integers. If a full product
3508 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3509 be sign-extended or zero-extended as appropriate to the width of the full
3510 product.</p>
3511
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3512<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3513 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3514 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3515 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3516 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3517
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3518<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3519<pre>
3520 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3521</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3522
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3523</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3524
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3525<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3526<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3527 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3528</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3529
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3530<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3531
3532<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3533<pre>
3534 &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]3535</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3536
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3537<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3538<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3539
3540<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3541<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3542 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3543 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3544
3545<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3546<p>The value produced is the floating point product of the two operands.</p>
3547
3548<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3549<pre>
3550 &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]3551</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3552
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3553</div>
3554
3555<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3556<h4>
3557 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3558</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3559
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3560<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3561
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3562<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3563<pre>
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3564 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3565 &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]3566</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3567
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3568<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3569<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3570
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3571<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3572<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3573 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3574 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3575
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3576<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3577<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3578
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3579<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3580 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3581
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3582<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3583
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3584<p>If the <tt>exact</tt> keyword is present, the result value of the
3585 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3586 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3587
3588
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3589<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3590<pre>
3591 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3592</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3593
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3594</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3595
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3596<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3597<h4>
3598 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3599</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3600
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3601<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3602
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3603<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3604<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3605 &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]3606 &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]3607</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3608
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3609<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3610<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3611
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3612<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3613<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3614 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3615 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3616
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3617<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3618<p>The value produced is the signed integer quotient of the two operands rounded
3619 towards zero.</p>
3620
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3621<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3622 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3623
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3624<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3625 undefined behavior; this is a rare case, but can occur, for example, by doing
3626 a 32-bit division of -2147483648 by -1.</p>
3627
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3628<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]3629 <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]3630 be rounded.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3631
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3632<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3633<pre>
3634 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3635</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3636
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3637</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3638
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3639<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3640<h4>
3641 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3642</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3643
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3644<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3645
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3646<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3647<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3648 &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]3649</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3650
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3651<h5>Overview:</h5>
3652<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3653
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3654<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3655<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3656 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3657 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3658
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3659<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3660<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3661
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3662<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3663<pre>
3664 &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]3665</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3666
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3667</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3668
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3669<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3670<h4>
3671 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3672</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3673
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3674<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3675
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3676<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3677<pre>
3678 &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]3679</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3680
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3681<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3682<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3683 division of its two arguments.</p>
3684
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3685<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3686<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3687 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3688 values. Both arguments must have identical types.</p>
3689
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3690<h5>Semantics:</h5>
3691<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3692 This instruction always performs an unsigned division to get the
3693 remainder.</p>
3694
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3695<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3696 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3697
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3698<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3699
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3700<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3701<pre>
3702 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3703</pre>
3704
3705</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3706
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3707<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3708<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3709 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3710</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3711
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3712<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3713
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3714<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3715<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3716 &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]3717</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3718
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3719<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3720<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3721 division of its two operands. This instruction can also take
3722 <a href="#t_vector">vector</a> versions of the values in which case the
3723 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3724
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3725<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3726<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3727 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3728 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3729
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3730<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3731<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sandsdea3a5e2011-03-07 09:12:24 +0000[diff] [blame]3732 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3733 <i>modulo</i> operator (where the result is either zero or has the same sign
3734 as the divisor, <tt>op2</tt>) of a value.
3735 For more information about the difference,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3736 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3737 Math Forum</a>. For a table of how this is implemented in various languages,
3738 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3739 Wikipedia: modulo operation</a>.</p>
3740
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3741<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3742 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3743
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3744<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3745 Overflow also leads to undefined behavior; this is a rare case, but can
3746 occur, for example, by taking the remainder of a 32-bit division of
3747 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3748 lets srem be implemented using instructions that return both the result of
3749 the division and the remainder.)</p>
3750
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3751<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3752<pre>
3753 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3754</pre>
3755
3756</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3757
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3758<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3759<h4>
3760 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3761</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3762
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3763<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3764
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3765<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3766<pre>
3767 &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]3768</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3769
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3770<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3771<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3772 its two operands.</p>
3773
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3774<h5>Arguments:</h5>
3775<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3776 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3777 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3778
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3779<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3780<p>This instruction returns the <i>remainder</i> of a division. The remainder
3781 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3782
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3783<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3784<pre>
3785 &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]3786</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3787
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3788</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3789
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3790</div>
3791
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3792<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3793<h3>
3794 <a name="bitwiseops">Bitwise Binary Operations</a>
3795</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3796
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3797<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3798
3799<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3800 program. They are generally very efficient instructions and can commonly be
3801 strength reduced from other instructions. They require two operands of the
3802 same type, execute an operation on them, and produce a single value. The
3803 resulting value is the same type as its operands.</p>
3804
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3805<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3806<h4>
3807 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3808</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3809
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3810<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3811
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3812<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3813<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3814 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3815 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3816 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3817 &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]3818</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3819
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3820<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3821<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3822 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3823
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3824<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3825<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3826 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3827 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3828
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3829<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3830<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3831 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3832 is (statically or dynamically) negative or equal to or larger than the number
3833 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3834 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3835 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3836
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3837<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3838 <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]3839 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3840 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3841 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3842 they would if the shift were expressed as a mul instruction with the same
3843 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3844
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3845<h5>Example:</h5>
3846<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3847 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3848 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3849 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3850 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3851 &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]3852</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3853
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3854</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3855
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3856<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3857<h4>
3858 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3859</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3860
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3861<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3862
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3863<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3864<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3865 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3866 &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]3867</pre>
3868
3869<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3870<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3871 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3872
3873<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3874<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3875 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3876 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3877
3878<h5>Semantics:</h5>
3879<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3880 significant bits of the result will be filled with zero bits after the shift.
3881 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3882 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3883 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3884 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3885
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3886<p>If the <tt>exact</tt> keyword is present, the result value of the
3887 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3888 shifted out are non-zero.</p>
3889
3890
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3891<h5>Example:</h5>
3892<pre>
3893 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3894 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3895 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3896 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3897 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3898 &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]3899</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3900
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3901</div>
3902
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3903<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3904<h4>
3905 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
3906</h4>
3907
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3908<div>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3909
3910<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3911<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3912 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3913 &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]3914</pre>
3915
3916<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3917<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3918 operand shifted to the right a specified number of bits with sign
3919 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3920
3921<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3922<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3923 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3924 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3925
3926<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3927<p>This instruction always performs an arithmetic shift right operation, The
3928 most significant bits of the result will be filled with the sign bit
3929 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3930 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3931 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3932 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3933
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3934<p>If the <tt>exact</tt> keyword is present, the result value of the
3935 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3936 shifted out are non-zero.</p>
3937
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3938<h5>Example:</h5>
3939<pre>
3940 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3941 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3942 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3943 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3944 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3945 &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]3946</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3947
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3948</div>
3949
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3950<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3951<h4>
3952 <a name="i_and">'<tt>and</tt>' Instruction</a>
3953</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3954
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3955<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3956
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3957<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3958<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3959 &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]3960</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3961
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3962<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3963<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3964 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3965
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3966<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3967<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3968 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3969 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3970
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3971<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3972<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3973
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3974<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3975 <tbody>
3976 <tr>
3977 <td>In0</td>
3978 <td>In1</td>
3979 <td>Out</td>
3980 </tr>
3981 <tr>
3982 <td>0</td>
3983 <td>0</td>
3984 <td>0</td>
3985 </tr>
3986 <tr>
3987 <td>0</td>
3988 <td>1</td>
3989 <td>0</td>
3990 </tr>
3991 <tr>
3992 <td>1</td>
3993 <td>0</td>
3994 <td>0</td>
3995 </tr>
3996 <tr>
3997 <td>1</td>
3998 <td>1</td>
3999 <td>1</td>
4000 </tr>
4001 </tbody>
4002</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4003
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4004<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4005<pre>
4006 &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]4007 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
4008 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4009</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4010</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4011<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4012<h4>
4013 <a name="i_or">'<tt>or</tt>' Instruction</a>
4014</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4015
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4016<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4017
4018<h5>Syntax:</h5>
4019<pre>
4020 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4021</pre>
4022
4023<h5>Overview:</h5>
4024<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4025 two operands.</p>
4026
4027<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4028<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4029 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4030 values. Both arguments must have identical types.</p>
4031
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4032<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4033<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4034
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4035<table border="1" cellspacing="0" cellpadding="4">
4036 <tbody>
4037 <tr>
4038 <td>In0</td>
4039 <td>In1</td>
4040 <td>Out</td>
4041 </tr>
4042 <tr>
4043 <td>0</td>
4044 <td>0</td>
4045 <td>0</td>
4046 </tr>
4047 <tr>
4048 <td>0</td>
4049 <td>1</td>
4050 <td>1</td>
4051 </tr>
4052 <tr>
4053 <td>1</td>
4054 <td>0</td>
4055 <td>1</td>
4056 </tr>
4057 <tr>
4058 <td>1</td>
4059 <td>1</td>
4060 <td>1</td>
4061 </tr>
4062 </tbody>
4063</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4064
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4065<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4066<pre>
4067 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4068 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4069 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4070</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4071
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4072</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4073
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4074<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4075<h4>
4076 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4077</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4078
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4079<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4080
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4081<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4082<pre>
4083 &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]4084</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4085
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4086<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4087<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4088 its two operands. The <tt>xor</tt> is used to implement the "one's
4089 complement" operation, which is the "~" operator in C.</p>
4090
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4091<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4092<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4093 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4094 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4095
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4096<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4097<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4098
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4099<table border="1" cellspacing="0" cellpadding="4">
4100 <tbody>
4101 <tr>
4102 <td>In0</td>
4103 <td>In1</td>
4104 <td>Out</td>
4105 </tr>
4106 <tr>
4107 <td>0</td>
4108 <td>0</td>
4109 <td>0</td>
4110 </tr>
4111 <tr>
4112 <td>0</td>
4113 <td>1</td>
4114 <td>1</td>
4115 </tr>
4116 <tr>
4117 <td>1</td>
4118 <td>0</td>
4119 <td>1</td>
4120 </tr>
4121 <tr>
4122 <td>1</td>
4123 <td>1</td>
4124 <td>0</td>
4125 </tr>
4126 </tbody>
4127</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4128
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4129<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4130<pre>
4131 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4132 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4133 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4134 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4135</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4136
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4137</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4138
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4139</div>
4140
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4141<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4142<h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4143 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4144</h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4145
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4146<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4147
4148<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4149 target-independent manner. These instructions cover the element-access and
4150 vector-specific operations needed to process vectors effectively. While LLVM
4151 does directly support these vector operations, many sophisticated algorithms
4152 will want to use target-specific intrinsics to take full advantage of a
4153 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4154
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4155<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4156<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4157 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4158</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4159
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4160<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4161
4162<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4163<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4164 &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]4165</pre>
4166
4167<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4168<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4169 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4170
4171
4172<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4173<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4174 of <a href="#t_vector">vector</a> type. The second operand is an index
4175 indicating the position from which to extract the element. The index may be
4176 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4177
4178<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4179<p>The result is a scalar of the same type as the element type of
4180 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4181 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4182 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4183
4184<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4185<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4186 &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]4187</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4188
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4189</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4190
4191<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4192<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4193 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4194</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4195
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4196<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4197
4198<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4199<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]4200 &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]4201</pre>
4202
4203<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4204<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4205 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4206
4207<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4208<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4209 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4210 whose type must equal the element type of the first operand. The third
4211 operand is an index indicating the position at which to insert the value.
4212 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4213
4214<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4215<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4216 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4217 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4218 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4219
4220<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4221<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4222 &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]4223</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4224
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4225</div>
4226
4227<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4228<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4229 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4230</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4231
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4232<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4233
4234<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4235<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4236 &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]4237</pre>
4238
4239<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4240<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4241 from two input vectors, returning a vector with the same element type as the
4242 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4243
4244<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4245<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4246 with types that match each other. The third argument is a shuffle mask whose
4247 element type is always 'i32'. The result of the instruction is a vector
4248 whose length is the same as the shuffle mask and whose element type is the
4249 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4250
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4251<p>The shuffle mask operand is required to be a constant vector with either
4252 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4253
4254<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4255<p>The elements of the two input vectors are numbered from left to right across
4256 both of the vectors. The shuffle mask operand specifies, for each element of
4257 the result vector, which element of the two input vectors the result element
4258 gets. The element selector may be undef (meaning "don't care") and the
4259 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4260
4261<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4262<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4263 &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]4264 &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]4265 &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]4266 &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]4267 &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]4268 &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]4269 &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]4270 &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]4271</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4272
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4273</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]4274
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4275</div>
4276
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4277<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4278<h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4279 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4280</h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4281
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4282<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4283
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4284<p>LLVM supports several instructions for working with
4285 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4286
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4287<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4288<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4289 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4290</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4291
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4292<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4293
4294<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4295<pre>
4296 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4297</pre>
4298
4299<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4300<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4301 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4302
4303<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4304<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4305 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4306 <a href="#t_array">array</a> type. The operands are constant indices to
4307 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4308 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4309 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4310 <ul>
4311 <li>Since the value being indexed is not a pointer, the first index is
4312 omitted and assumed to be zero.</li>
4313 <li>At least one index must be specified.</li>
4314 <li>Not only struct indices but also array indices must be in
4315 bounds.</li>
4316 </ul>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4317
4318<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4319<p>The result is the value at the position in the aggregate specified by the
4320 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4321
4322<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4323<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4324 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4325</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4326
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4327</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4328
4329<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4330<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4331 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4332</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4333
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4334<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4335
4336<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4337<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame]4338 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt;{, <idx>}* <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4339</pre>
4340
4341<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4342<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4343 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4344
4345<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4346<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4347 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4348 <a href="#t_array">array</a> type. The second operand is a first-class
4349 value to insert. The following operands are constant indices indicating
4350 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]4351 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4352 value to insert must have the same type as the value identified by the
4353 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4354
4355<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4356<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4357 that of <tt>val</tt> except that the value at the position specified by the
4358 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4359
4360<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4361<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame]4362 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4363 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4364 %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]4365</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4366
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4367</div>
4368
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4369</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4370
4371<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4372<h3>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4373 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4374</h3>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4375
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4376<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4377
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4378<p>A key design point of an SSA-based representation is how it represents
4379 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4380 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4381 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4382
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4383<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4384<h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4385 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4386</h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4387
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4388<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4389
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4390<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4391<pre>
Dan Gohmanf75a7d32010-05-28 01:14:11 +0000[diff] [blame]4392 &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]4393</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4394
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4395<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4396<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4397 currently executing function, to be automatically released when this function
4398 returns to its caller. The object is always allocated in the generic address
4399 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4400
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4401<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4402<p>The '<tt>alloca</tt>' instruction
4403 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4404 runtime stack, returning a pointer of the appropriate type to the program.
4405 If "NumElements" is specified, it is the number of elements allocated,
4406 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4407 specified, the value result of the allocation is guaranteed to be aligned to
4408 at least that boundary. If not specified, or if zero, the target can choose
4409 to align the allocation on any convenient boundary compatible with the
4410 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4411
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4412<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4413
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4414<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4415<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4416 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4417 memory is automatically released when the function returns. The
4418 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4419 variables that must have an address available. When the function returns
4420 (either with the <tt><a href="#i_ret">ret</a></tt>
4421 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4422 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4423
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4424<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4425<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4426 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4427 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4428 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4429 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4430</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4431
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4432</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4433
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4434<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4435<h4>
4436 <a name="i_load">'<tt>load</tt>' Instruction</a>
4437</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4438
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4439<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4440
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4441<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4442<pre>
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4443 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4444 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4445 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4446</pre>
4447
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4448<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4449<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4450
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4451<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4452<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4453 from which to load. The pointer must point to
4454 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4455 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4456 number or order of execution of this <tt>load</tt> with other <a
4457 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4458
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4459<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4460 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]4461 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4462 alignment for the target. It is the responsibility of the code emitter to
4463 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4464 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4465 produce less efficient code. An alignment of 1 is always safe.</p>
4466
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4467<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4468 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4469 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4470 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4471 and code generator that this load is not expected to be reused in the cache.
4472 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4473 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4474
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4475<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4476<p>The location of memory pointed to is loaded. If the value being loaded is of
4477 scalar type then the number of bytes read does not exceed the minimum number
4478 of bytes needed to hold all bits of the type. For example, loading an
4479 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4480 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4481 is undefined if the value was not originally written using a store of the
4482 same type.</p>
4483
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4484<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4485<pre>
4486 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4487 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4488 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4489</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4490
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4491</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4492
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4493<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4494<h4>
4495 <a name="i_store">'<tt>store</tt>' Instruction</a>
4496</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4497
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4498<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4499
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4500<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4501<pre>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4502 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>
4503 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]4504</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4505
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4506<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4507<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4508
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4509<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4510<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4511 and an address at which to store it. The type of the
4512 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4513 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4514 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4515 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4516 order of execution of this <tt>store</tt> with other <a
4517 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4518
4519<p>The optional constant "align" argument specifies the alignment of the
4520 operation (that is, the alignment of the memory address). A value of 0 or an
4521 omitted "align" argument means that the operation has the preferential
4522 alignment for the target. It is the responsibility of the code emitter to
4523 ensure that the alignment information is correct. Overestimating the
4524 alignment results in an undefined behavior. Underestimating the alignment may
4525 produce less efficient code. An alignment of 1 is always safe.</p>
4526
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4527<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4528 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4529 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4530 instruction tells the optimizer and code generator that this load is
4531 not expected to be reused in the cache. The code generator may
4532 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4533 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4534
4535
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4536<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4537<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4538 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4539 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4540 does not exceed the minimum number of bytes needed to hold all bits of the
4541 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4542 writing a value of a type like <tt>i20</tt> with a size that is not an
4543 integral number of bytes, it is unspecified what happens to the extra bits
4544 that do not belong to the type, but they will typically be overwritten.</p>
4545
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4546<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4547<pre>
4548 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4549 store i32 3, i32* %ptr <i>; yields {void}</i>
4550 %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]4551</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4552
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4553</div>
4554
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4555<!-- _______________________________________________________________________ -->
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame^]4556<div class="doc_subsubsection"> <a name="i_fence">'<tt>fence</tt>'
4557Instruction</a> </div>
4558
4559<div class="doc_text">
4560
4561<h5>Syntax:</h5>
4562<pre>
4563 fence [singlethread] &lt;ordering&gt; <i>; yields {void}</i>
4564</pre>
4565
4566<h5>Overview:</h5>
4567<p>The '<tt>fence</tt>' instruction is used to introduce happens-before edges
4568between operations.</p>
4569
4570<h5>Arguments:</h5> <p>'<code>fence</code>' instructions take an <a
4571href="#ordering">ordering</a> argument which defines what
4572<i>synchronizes-with</i> edges they add. They can only be given
4573<code>acquire</code>, <code>release</code>, <code>acq_rel</code>, and
4574<code>seq_cst</code> orderings.</p>
4575
4576<h5>Semantics:</h5>
4577<p>A fence <var>A</var> which has (at least) <code>release</code> ordering
4578semantics <i>synchronizes with</i> a fence <var>B</var> with (at least)
4579<code>acquire</code> ordering semantics if and only if there exist atomic
4580operations <var>X</var> and <var>Y</var>, both operating on some atomic object
4581<var>M</var>, such that <var>A</var> is sequenced before <var>X</var>,
4582<var>X</var> modifies <var>M</var> (either directly or through some side effect
4583of a sequence headed by <var>X</var>), <var>Y</var> is sequenced before
4584<var>B</var>, and <var>Y</var> observes <var>M</var>. This provides a
4585<i>happens-before</i> dependency between <var>A</var> and <var>B</var>. Rather
4586than an explicit <code>fence</code>, one (but not both) of the atomic operations
4587<var>X</var> or <var>Y</var> might provide a <code>release</code> or
4588<code>acquire</code> (resp.) ordering constraint and still
4589<i>synchronize-with</i> the explicit <code>fence</code> and establish the
4590<i>happens-before</i> edge.</p>
4591
4592<p>A <code>fence</code> which has <code>seq_cst</code> ordering, in addition to
4593having both <code>acquire</code> and <code>release</code> semantics specified
4594above, participates in the global program order of other <code>seq_cst</code>
4595operations and/or fences.</p>
4596
4597<p>The optional "<a href="#singlethread"><code>singlethread</code></a>" argument
4598specifies that the fence only synchronizes with other fences in the same
4599thread. (This is useful for interacting with signal handlers.)</p>
4600
4601<p>FIXME: This instruction is a work in progress; until it is finished, use
4602 llvm.memory.barrier.
4603
4604<h5>Example:</h5>
4605<pre>
4606 fence acquire <i>; yields {void}</i>
4607 fence singlethread seq_cst <i>; yields {void}</i>
4608</pre>
4609
4610</div>
4611
4612<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4613<h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4614 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4615</h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +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 Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4619<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4620<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4621 &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]4622 &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]4623</pre>
4624
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4625<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4626<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4627 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4628 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4629
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4630<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4631<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4632 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4633 elements of the aggregate object are indexed. The interpretation of each
4634 index is dependent on the type being indexed into. The first index always
4635 indexes the pointer value given as the first argument, the second index
4636 indexes a value of the type pointed to (not necessarily the value directly
4637 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4638 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4639 vectors, and structs. Note that subsequent types being indexed into
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4640 can never be pointers, since that would require loading the pointer before
4641 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4642
4643<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]4644 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4645 integer <b>constants</b> are allowed. When indexing into an array, pointer
4646 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]4647 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4648
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4649<p>For example, let's consider a C code fragment and how it gets compiled to
4650 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4651
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4652<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4653struct RT {
4654 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4655 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4656 char C;
4657};
4658struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4659 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4660 double Y;
4661 struct RT Z;
4662};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4663
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4664int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4665 return &amp;s[1].Z.B[5][13];
4666}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4667</pre>
4668
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4669<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4670
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4671<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]4672%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4673%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4674
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4675define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4676entry:
4677 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4678 ret i32* %reg
4679}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4680</pre>
4681
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4682<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4683<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]4684 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4685 }</tt>' type, a structure. The second index indexes into the third element
4686 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4687 i8 }</tt>' type, another structure. The third index indexes into the second
4688 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4689 array. The two dimensions of the array are subscripted into, yielding an
4690 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4691 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4692
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4693<p>Note that it is perfectly legal to index partially through a structure,
4694 returning a pointer to an inner element. Because of this, the LLVM code for
4695 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4696
4697<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4698 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4699 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4700 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4701 %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]4702 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4703 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4704 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4705 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4706</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]4707
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4708<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]4709 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4710 base pointer is not an <i>in bounds</i> address of an allocated object,
4711 or if any of the addresses that would be formed by successive addition of
4712 the offsets implied by the indices to the base address with infinitely
4713 precise arithmetic are not an <i>in bounds</i> address of that allocated
4714 object. The <i>in bounds</i> addresses for an allocated object are all
4715 the addresses that point into the object, plus the address one byte past
4716 the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4717
4718<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4719 the base address with silently-wrapping two's complement arithmetic, and
4720 the result value of the <tt>getelementptr</tt> may be outside the object
4721 pointed to by the base pointer. The result value may not necessarily be
4722 used to access memory though, even if it happens to point into allocated
4723 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4724 section for more information.</p>
4725
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4726<p>The getelementptr instruction is often confusing. For some more insight into
4727 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4728
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4729<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4730<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4731 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4732 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4733 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4734 %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]4735 <i>; yields i8*:eptr</i>
4736 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]4737 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]4738 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4739</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4740
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4741</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4742
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4743</div>
4744
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4745<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4746<h3>
4747 <a name="convertops">Conversion Operations</a>
4748</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4749
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4750<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4751
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4752<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4753 which all take a single operand and a type. They perform various bit
4754 conversions on the operand.</p>
4755
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4756<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4757<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4758 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4759</h4>
4760
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4761<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4762
4763<h5>Syntax:</h5>
4764<pre>
4765 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4766</pre>
4767
4768<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4769<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4770 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4771
4772<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4773<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
4774 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4775 of the same number of integers.
4776 The bit size of the <tt>value</tt> must be larger than
4777 the bit size of the destination type, <tt>ty2</tt>.
4778 Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4779
4780<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4781<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4782 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4783 source size must be larger than the destination size, <tt>trunc</tt> cannot
4784 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4785
4786<h5>Example:</h5>
4787<pre>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4788 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
4789 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4790 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
4791 %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]4792</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4793
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4794</div>
4795
4796<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4797<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4798 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4799</h4>
4800
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4801<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4802
4803<h5>Syntax:</h5>
4804<pre>
4805 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4806</pre>
4807
4808<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4809<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4810 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4811
4812
4813<h5>Arguments:</h5>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]4814<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
4815 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4816 of the same number of integers.
4817 The bit size of the <tt>value</tt> must be smaller than
4818 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4819 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4820
4821<h5>Semantics:</h5>
4822<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]4823 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4824
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]4825<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]4826
4827<h5>Example:</h5>
4828<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4829 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4830 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]4831 %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]4832</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4833
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4834</div>
4835
4836<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4837<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4838 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4839</h4>
4840
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4841<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4842
4843<h5>Syntax:</h5>
4844<pre>
4845 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4846</pre>
4847
4848<h5>Overview:</h5>
4849<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4850
4851<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4852<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
4853 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4854 of the same number of integers.
4855 The bit size of the <tt>value</tt> must be smaller than
4856 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4857 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4858
4859<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4860<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4861 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4862 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4863
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4864<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]4865
4866<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4867<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4868 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4869 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4870 %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]4871</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4872
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4873</div>
4874
4875<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4876<h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4877 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4878</h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4879
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4880<div>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4881
4882<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4883<pre>
4884 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4885</pre>
4886
4887<h5>Overview:</h5>
4888<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4889 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4890
4891<h5>Arguments:</h5>
4892<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4893 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4894 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]4895 <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]4896 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4897
4898<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4899<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4900 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4901 <a href="#t_floating">floating point</a> type. If the value cannot fit
4902 within the destination type, <tt>ty2</tt>, then the results are
4903 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4904
4905<h5>Example:</h5>
4906<pre>
4907 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4908 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4909</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4910
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4911</div>
4912
4913<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4914<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4915 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4916</h4>
4917
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4918<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4919
4920<h5>Syntax:</h5>
4921<pre>
4922 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4923</pre>
4924
4925<h5>Overview:</h5>
4926<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]4927 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4928
4929<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4930<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4931 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4932 a <a href="#t_floating">floating point</a> type to cast it to. The source
4933 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4934
4935<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4936<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4937 <a href="#t_floating">floating point</a> type to a larger
4938 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4939 used to make a <i>no-op cast</i> because it always changes bits. Use
4940 <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]4941
4942<h5>Example:</h5>
4943<pre>
Nick Lewycky5bb3ece2011-03-31 18:20:19 +0000[diff] [blame]4944 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
4945 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4946</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4947
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4948</div>
4949
4950<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4951<h4>
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]4952 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4953</h4>
4954
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4955<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4956
4957<h5>Syntax:</h5>
4958<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4959 &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]4960</pre>
4961
4962<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4963<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4964 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4965
4966<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4967<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4968 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4969 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4970 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4971 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4972
4973<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4974<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4975 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4976 towards zero) unsigned integer value. If the value cannot fit
4977 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4978
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4979<h5>Example:</h5>
4980<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4981 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4982 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4983 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4984</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4985
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4986</div>
4987
4988<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4989<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4990 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4991</h4>
4992
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4993<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4994
4995<h5>Syntax:</h5>
4996<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4997 &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]4998</pre>
4999
5000<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5001<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5002 <a href="#t_floating">floating point</a> <tt>value</tt> to
5003 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5004
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5005<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5006<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
5007 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5008 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5009 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5010 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5011
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5012<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5013<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5014 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5015 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
5016 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5017
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]5018<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5019<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5020 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]5021 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5022 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5023</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5024
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5025</div>
5026
5027<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5028<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5029 <a name="i_uitofp">'<tt>uitofp .. 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>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5036 &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]5037</pre>
5038
5039<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5040<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5041 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5042
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5043<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5044<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]5045 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5046 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5047 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5048 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5049
5050<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5051<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5052 integer quantity and converts it to the corresponding floating point
5053 value. If the value cannot fit in the floating point value, the results are
5054 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5055
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5056<h5>Example:</h5>
5057<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5058 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5059 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5060</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5061
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5062</div>
5063
5064<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5065<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5066 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5067</h4>
5068
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5069<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5070
5071<h5>Syntax:</h5>
5072<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5073 &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]5074</pre>
5075
5076<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5077<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5078 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5079
5080<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5081<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]5082 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5083 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5084 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5085 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5086
5087<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5088<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5089 quantity and converts it to the corresponding floating point value. If the
5090 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5091
5092<h5>Example:</h5>
5093<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5094 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5095 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5096</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5097
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5098</div>
5099
5100<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5101<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5102 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5103</h4>
5104
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5105<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5106
5107<h5>Syntax:</h5>
5108<pre>
5109 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5110</pre>
5111
5112<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5113<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5114 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5115
5116<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5117<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5118 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5119 <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]5120
5121<h5>Semantics:</h5>
5122<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5123 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5124 truncating or zero extending that value to the size of the integer type. If
5125 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5126 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5127 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5128 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5129
5130<h5>Example:</h5>
5131<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5132 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5133 %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]5134</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5135
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5136</div>
5137
5138<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5139<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5140 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5141</h4>
5142
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5143<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5144
5145<h5>Syntax:</h5>
5146<pre>
5147 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5148</pre>
5149
5150<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5151<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5152 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5153
5154<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]5155<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5156 value to cast, and a type to cast it to, which must be a
5157 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5158
5159<h5>Semantics:</h5>
5160<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5161 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5162 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5163 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5164 than the size of a pointer then a zero extension is done. If they are the
5165 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5166
5167<h5>Example:</h5>
5168<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5169 %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]5170 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5171 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5172</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5173
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5174</div>
5175
5176<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5177<h4>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5178 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5179</h4>
5180
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5181<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5182
5183<h5>Syntax:</h5>
5184<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5185 &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]5186</pre>
5187
5188<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5189<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5190 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5191
5192<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5193<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5194 non-aggregate first class value, and a type to cast it to, which must also be
5195 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5196 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5197 identical. If the source type is a pointer, the destination type must also be
5198 a pointer. This instruction supports bitwise conversion of vectors to
5199 integers and to vectors of other types (as long as they have the same
5200 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5201
5202<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5203<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5204 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5205 this conversion. The conversion is done as if the <tt>value</tt> had been
5206 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5207 be converted to other pointer types with this instruction. To convert
5208 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5209 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5210
5211<h5>Example:</h5>
5212<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5213 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5214 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5215 %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]5216</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5217
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5218</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5219
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5220</div>
5221
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5222<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5223<h3>
5224 <a name="otherops">Other Operations</a>
5225</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5226
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5227<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5228
5229<p>The instructions in this category are the "miscellaneous" instructions, which
5230 defy better classification.</p>
5231
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5232<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5233<h4>
5234 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5235</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5236
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5237<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5238
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5239<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5240<pre>
5241 &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]5242</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5243
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5244<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5245<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5246 boolean values based on comparison of its two integer, integer vector, or
5247 pointer operands.</p>
5248
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5249<h5>Arguments:</h5>
5250<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5251 the condition code indicating the kind of comparison to perform. It is not a
5252 value, just a keyword. The possible condition code are:</p>
5253
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5254<ol>
5255 <li><tt>eq</tt>: equal</li>
5256 <li><tt>ne</tt>: not equal </li>
5257 <li><tt>ugt</tt>: unsigned greater than</li>
5258 <li><tt>uge</tt>: unsigned greater or equal</li>
5259 <li><tt>ult</tt>: unsigned less than</li>
5260 <li><tt>ule</tt>: unsigned less or equal</li>
5261 <li><tt>sgt</tt>: signed greater than</li>
5262 <li><tt>sge</tt>: signed greater or equal</li>
5263 <li><tt>slt</tt>: signed less than</li>
5264 <li><tt>sle</tt>: signed less or equal</li>
5265</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5266
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]5267<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5268 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5269 typed. They must also be identical types.</p>
5270
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5271<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5272<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5273 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5274 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]5275 result, as follows:</p>
5276
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5277<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5278 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5279 <tt>false</tt> otherwise. No sign interpretation is necessary or
5280 performed.</li>
5281
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5282 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5283 <tt>false</tt> otherwise. No sign interpretation is necessary or
5284 performed.</li>
5285
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5286 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5287 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5288
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5289 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5290 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5291 to <tt>op2</tt>.</li>
5292
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5293 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5294 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5295
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5296 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5297 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5298
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5299 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5300 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5301
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5302 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5303 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5304 to <tt>op2</tt>.</li>
5305
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5306 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5307 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5308
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5309 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5310 <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]5311</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5312
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5313<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5314 values are compared as if they were integers.</p>
5315
5316<p>If the operands are integer vectors, then they are compared element by
5317 element. The result is an <tt>i1</tt> vector with the same number of elements
5318 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5319
5320<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5321<pre>
5322 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5323 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5324 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5325 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5326 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5327 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5328</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5329
5330<p>Note that the code generator does not yet support vector types with
5331 the <tt>icmp</tt> instruction.</p>
5332
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5333</div>
5334
5335<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5336<h4>
5337 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5338</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5339
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5340<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5341
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5342<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5343<pre>
5344 &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]5345</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5346
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5347<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5348<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5349 values based on comparison of its operands.</p>
5350
5351<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]5352(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5353
5354<p>If the operands are floating point vectors, then the result type is a vector
5355 of boolean with the same number of elements as the operands being
5356 compared.</p>
5357
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5358<h5>Arguments:</h5>
5359<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5360 the condition code indicating the kind of comparison to perform. It is not a
5361 value, just a keyword. The possible condition code are:</p>
5362
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5363<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5364 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5365 <li><tt>oeq</tt>: ordered and equal</li>
5366 <li><tt>ogt</tt>: ordered and greater than </li>
5367 <li><tt>oge</tt>: ordered and greater than or equal</li>
5368 <li><tt>olt</tt>: ordered and less than </li>
5369 <li><tt>ole</tt>: ordered and less than or equal</li>
5370 <li><tt>one</tt>: ordered and not equal</li>
5371 <li><tt>ord</tt>: ordered (no nans)</li>
5372 <li><tt>ueq</tt>: unordered or equal</li>
5373 <li><tt>ugt</tt>: unordered or greater than </li>
5374 <li><tt>uge</tt>: unordered or greater than or equal</li>
5375 <li><tt>ult</tt>: unordered or less than </li>
5376 <li><tt>ule</tt>: unordered or less than or equal</li>
5377 <li><tt>une</tt>: unordered or not equal</li>
5378 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5379 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5380</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5381
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5382<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5383 <i>unordered</i> means that either operand may be a QNAN.</p>
5384
5385<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5386 a <a href="#t_floating">floating point</a> type or
5387 a <a href="#t_vector">vector</a> of floating point type. They must have
5388 identical types.</p>
5389
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5390<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]5391<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5392 according to the condition code given as <tt>cond</tt>. If the operands are
5393 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5394 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5395 follows:</p>
5396
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5397<ol>
5398 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5399
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5400 <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]5401 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5402
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5403 <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]5404 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5405
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5406 <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]5407 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5408
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5409 <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]5410 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5411
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5412 <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]5413 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5414
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5415 <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]5416 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5417
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5418 <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]5419
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5420 <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]5421 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5422
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5423 <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]5424 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5425
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5426 <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]5427 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5428
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5429 <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]5430 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5431
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5432 <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]5433 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5434
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5435 <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]5436 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5437
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5438 <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]5439
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5440 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5441</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5442
5443<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5444<pre>
5445 &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]5446 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5447 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5448 &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]5449</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5450
5451<p>Note that the code generator does not yet support vector types with
5452 the <tt>fcmp</tt> instruction.</p>
5453
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5454</div>
5455
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5456<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5457<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5458 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5459</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5460
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5461<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5462
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5463<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5464<pre>
5465 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5466</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5467
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5468<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5469<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5470 SSA graph representing the function.</p>
5471
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5472<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5473<p>The type of the incoming values is specified with the first type field. After
5474 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5475 one pair for each predecessor basic block of the current block. Only values
5476 of <a href="#t_firstclass">first class</a> type may be used as the value
5477 arguments to the PHI node. Only labels may be used as the label
5478 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5479
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5480<p>There must be no non-phi instructions between the start of a basic block and
5481 the PHI instructions: i.e. PHI instructions must be first in a basic
5482 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5483
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5484<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5485 occur on the edge from the corresponding predecessor block to the current
5486 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5487 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]5488
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5489<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5490<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5491 specified by the pair corresponding to the predecessor basic block that
5492 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5493
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5494<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5495<pre>
5496Loop: ; Infinite loop that counts from 0 on up...
5497 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5498 %nextindvar = add i32 %indvar, 1
5499 br label %Loop
5500</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5501
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5502</div>
5503
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5504<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5505<h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5506 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5507</h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5508
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5509<div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5510
5511<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5512<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5513 &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>
5514
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5515 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5516</pre>
5517
5518<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5519<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5520 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5521
5522
5523<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5524<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5525 values indicating the condition, and two values of the
5526 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5527 vectors and the condition is a scalar, then entire vectors are selected, not
5528 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5529
5530<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5531<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5532 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5533
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5534<p>If the condition is a vector of i1, then the value arguments must be vectors
5535 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5536
5537<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5538<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5539 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5540</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5541
5542<p>Note that the code generator does not yet support conditions
5543 with vector type.</p>
5544
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5545</div>
5546
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5547<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5548<h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5549 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5550</h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5551
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5552<div>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5553
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5554<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5555<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]5556 &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]5557</pre>
5558
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5559<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5560<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5561
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5562<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5563<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5564
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5565<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5566 <li>The optional "tail" marker indicates that the callee function does not
5567 access any allocas or varargs in the caller. Note that calls may be
5568 marked "tail" even if they do not occur before
5569 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5570 present, the function call is eligible for tail call optimization,
5571 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Chengdc444e92010-03-08 21:05:02 +0000[diff] [blame]5572 optimized into a jump</a>. The code generator may optimize calls marked
5573 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5574 sibling call optimization</a> when the caller and callee have
5575 matching signatures, or 2) forced tail call optimization when the
5576 following extra requirements are met:
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5577 <ul>
5578 <li>Caller and callee both have the calling
5579 convention <tt>fastcc</tt>.</li>
5580 <li>The call is in tail position (ret immediately follows call and ret
5581 uses value of call or is void).</li>
5582 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohmanfbbee8d2010-03-02 01:08:11 +0000[diff] [blame]5583 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5584 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5585 constraints are met.</a></li>
5586 </ul>
5587 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5588
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5589 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5590 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5591 defaults to using C calling conventions. The calling convention of the
5592 call must match the calling convention of the target function, or else the
5593 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5594
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5595 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5596 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5597 '<tt>inreg</tt>' attributes are valid here.</li>
5598
5599 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5600 type of the return value. Functions that return no value are marked
5601 <tt><a href="#t_void">void</a></tt>.</li>
5602
5603 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5604 being invoked. The argument types must match the types implied by this
5605 signature. This type can be omitted if the function is not varargs and if
5606 the function type does not return a pointer to a function.</li>
5607
5608 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5609 be invoked. In most cases, this is a direct function invocation, but
5610 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5611 to function value.</li>
5612
5613 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]5614 signature argument types and parameter attributes. All arguments must be
5615 of <a href="#t_firstclass">first class</a> type. If the function
5616 signature indicates the function accepts a variable number of arguments,
5617 the extra arguments can be specified.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5618
5619 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5620 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5621 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5622</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5623
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5624<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5625<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5626 a specified function, with its incoming arguments bound to the specified
5627 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5628 function, control flow continues with the instruction after the function
5629 call, and the return value of the function is bound to the result
5630 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5631
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5632<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5633<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]5634 %retval = call i32 @test(i32 %argc)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]5635 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]5636 %X = tail call i32 @foo() <i>; yields i32</i>
5637 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5638 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]5639
5640 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5641 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]5642 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5643 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]5644 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]5645 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5646</pre>
5647
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5648<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]5649standard C99 library as being the C99 library functions, and may perform
5650optimizations or generate code for them under that assumption. This is
5651something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5652freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5653
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5654</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5655
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5656<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5657<h4>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]5658 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5659</h4>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5660
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5661<div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5662
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5663<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5664<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5665 &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]5666</pre>
5667
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5668<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5669<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5670 the "variable argument" area of a function call. It is used to implement the
5671 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5672
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5673<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5674<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5675 argument. It returns a value of the specified argument type and increments
5676 the <tt>va_list</tt> to point to the next argument. The actual type
5677 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5678
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5679<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5680<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5681 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5682 to the next argument. For more information, see the variable argument
5683 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5684
5685<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]5686 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5687 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5688
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5689<p><tt>va_arg</tt> is an LLVM instruction instead of
5690 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5691 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5692
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5693<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5694<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5695
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5696<p>Note that the code generator does not yet fully support va_arg on many
5697 targets. Also, it does not currently support va_arg with aggregate types on
5698 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]5699
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5700</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5701
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5702</div>
5703
5704</div>
5705
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5706<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5707<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]5708<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5709
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5710<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5711
5712<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5713 well known names and semantics and are required to follow certain
5714 restrictions. Overall, these intrinsics represent an extension mechanism for
5715 the LLVM language that does not require changing all of the transformations
5716 in LLVM when adding to the language (or the bitcode reader/writer, the
5717 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5718
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5719<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5720 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5721 begin with this prefix. Intrinsic functions must always be external
5722 functions: you cannot define the body of intrinsic functions. Intrinsic
5723 functions may only be used in call or invoke instructions: it is illegal to
5724 take the address of an intrinsic function. Additionally, because intrinsic
5725 functions are part of the LLVM language, it is required if any are added that
5726 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5727
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5728<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5729 family of functions that perform the same operation but on different data
5730 types. Because LLVM can represent over 8 million different integer types,
5731 overloading is used commonly to allow an intrinsic function to operate on any
5732 integer type. One or more of the argument types or the result type can be
5733 overloaded to accept any integer type. Argument types may also be defined as
5734 exactly matching a previous argument's type or the result type. This allows
5735 an intrinsic function which accepts multiple arguments, but needs all of them
5736 to be of the same type, to only be overloaded with respect to a single
5737 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5738
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5739<p>Overloaded intrinsics will have the names of its overloaded argument types
5740 encoded into its function name, each preceded by a period. Only those types
5741 which are overloaded result in a name suffix. Arguments whose type is matched
5742 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5743 can take an integer of any width and returns an integer of exactly the same
5744 integer width. This leads to a family of functions such as
5745 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5746 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5747 suffix is required. Because the argument's type is matched against the return
5748 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5749
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5750<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5751 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5752
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5753<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5754<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5755 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5756</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5757
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5758<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5759
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5760<p>Variable argument support is defined in LLVM with
5761 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5762 intrinsic functions. These functions are related to the similarly named
5763 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5764
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5765<p>All of these functions operate on arguments that use a target-specific value
5766 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5767 not define what this type is, so all transformations should be prepared to
5768 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5769
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]5770<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]5771 instruction and the variable argument handling intrinsic functions are
5772 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5773
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]5774<pre class="doc_code">
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5775define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5776 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5777 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5778 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5779 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5780
5781 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5782 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5783
5784 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5785 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5786 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5787 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5788 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5789
5790 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5791 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5792 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5793}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5794
5795declare void @llvm.va_start(i8*)
5796declare void @llvm.va_copy(i8*, i8*)
5797declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5798</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5799
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5800<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5801<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5802 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5803</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5804
5805
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5806<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5807
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5808<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5809<pre>
5810 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5811</pre>
5812
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5813<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5814<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5815 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]5816
5817<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5818<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]5819
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5820<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5821<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]5822 macro available in C. In a target-dependent way, it initializes
5823 the <tt>va_list</tt> element to which the argument points, so that the next
5824 call to <tt>va_arg</tt> will produce the first variable argument passed to
5825 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5826 need to know the last argument of the function as the compiler can figure
5827 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5828
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5829</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5830
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5831<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5832<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5833 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5834</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5835
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5836<div>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5837
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5838<h5>Syntax:</h5>
5839<pre>
5840 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5841</pre>
5842
5843<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5844<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5845 which has been initialized previously
5846 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5847 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5848
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5849<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5850<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]5851
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5852<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5853<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]5854 macro available in C. In a target-dependent way, it destroys
5855 the <tt>va_list</tt> element to which the argument points. Calls
5856 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5857 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5858 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5859
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5860</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5861
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5862<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5863<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5864 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5865</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5866
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5867<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5868
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5869<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5870<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5871 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5872</pre>
5873
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5874<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5875<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5876 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5877
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5878<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5879<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]5880 The second argument is a pointer to a <tt>va_list</tt> element to copy
5881 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5882
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5883<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5884<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]5885 macro available in C. In a target-dependent way, it copies the
5886 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5887 element. This intrinsic is necessary because
5888 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5889 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5890
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5891</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5892
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5893</div>
5894
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5895<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5896<h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5897 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5898</h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5899
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5900<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5901
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5902<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5903Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5904intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5905roots on the stack</a>, as well as garbage collector implementations that
5906require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5907barriers. Front-ends for type-safe garbage collected languages should generate
5908these intrinsics to make use of the LLVM garbage collectors. For more details,
5909see <a href="GarbageCollection.html">Accurate Garbage Collection with
5910LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5911
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5912<p>The garbage collection intrinsics only operate on objects in the generic
5913 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5914
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5915<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5916<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5917 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5918</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5919
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5920<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5921
5922<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5923<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5924 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5925</pre>
5926
5927<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]5928<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]5929 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5930
5931<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5932<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5933 root pointer. The second pointer (which must be either a constant or a
5934 global value address) contains the meta-data to be associated with the
5935 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5936
5937<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]5938<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]5939 location. At compile-time, the code generator generates information to allow
5940 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5941 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5942 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5943
5944</div>
5945
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5946<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5947<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5948 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5949</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5950
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5951<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5952
5953<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5954<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5955 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5956</pre>
5957
5958<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5959<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5960 locations, allowing garbage collector implementations that require read
5961 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5962
5963<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5964<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]5965 allocated from the garbage collector. The first object is a pointer to the
5966 start of the referenced object, if needed by the language runtime (otherwise
5967 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5968
5969<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5970<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5971 instruction, but may be replaced with substantially more complex code by the
5972 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5973 may only be used in a function which <a href="#gc">specifies a GC
5974 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5975
5976</div>
5977
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5978<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5979<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5980 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5981</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5982
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5983<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5984
5985<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5986<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5987 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5988</pre>
5989
5990<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5991<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5992 locations, allowing garbage collector implementations that require write
5993 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5994
5995<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5996<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]5997 object to store it to, and the third is the address of the field of Obj to
5998 store to. If the runtime does not require a pointer to the object, Obj may
5999 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6000
6001<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6002<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6003 instruction, but may be replaced with substantially more complex code by the
6004 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
6005 may only be used in a function which <a href="#gc">specifies a GC
6006 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6007
6008</div>
6009
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6010</div>
6011
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6012<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6013<h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6014 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6015</h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6016
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6017<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6018
6019<p>These intrinsics are provided by LLVM to expose special features that may
6020 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6021
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6022<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6023<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6024 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6025</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6026
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6027<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6028
6029<h5>Syntax:</h5>
6030<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6031 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6032</pre>
6033
6034<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6035<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
6036 target-specific value indicating the return address of the current function
6037 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6038
6039<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6040<p>The argument to this intrinsic indicates which function to return the address
6041 for. Zero indicates the calling function, one indicates its caller, etc.
6042 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6043
6044<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6045<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
6046 indicating the return address of the specified call frame, or zero if it
6047 cannot be identified. The value returned by this intrinsic is likely to be
6048 incorrect or 0 for arguments other than zero, so it should only be used for
6049 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6050
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6051<p>Note that calling this intrinsic does not prevent function inlining or other
6052 aggressive transformations, so the value returned may not be that of the
6053 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6054
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6055</div>
6056
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6057<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6058<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6059 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6060</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6061
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6062<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6063
6064<h5>Syntax:</h5>
6065<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6066 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6067</pre>
6068
6069<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6070<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6071 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6072
6073<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6074<p>The argument to this intrinsic indicates which function to return the frame
6075 pointer for. Zero indicates the calling function, one indicates its caller,
6076 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6077
6078<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6079<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6080 indicating the frame address of the specified call frame, or zero if it
6081 cannot be identified. The value returned by this intrinsic is likely to be
6082 incorrect or 0 for arguments other than zero, so it should only be used for
6083 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6084
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6085<p>Note that calling this intrinsic does not prevent function inlining or other
6086 aggressive transformations, so the value returned may not be that of the
6087 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6088
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6089</div>
6090
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6091<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6092<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6093 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6094</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6095
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6096<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6097
6098<h5>Syntax:</h5>
6099<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6100 declare i8* @llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6101</pre>
6102
6103<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6104<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6105 of the function stack, for use
6106 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6107 useful for implementing language features like scoped automatic variable
6108 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6109
6110<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6111<p>This intrinsic returns a opaque pointer value that can be passed
6112 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6113 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6114 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6115 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6116 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6117 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6118
6119</div>
6120
6121<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6122<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6123 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6124</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6125
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6126<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6127
6128<h5>Syntax:</h5>
6129<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6130 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6131</pre>
6132
6133<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6134<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6135 the function stack to the state it was in when the
6136 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6137 executed. This is useful for implementing language features like scoped
6138 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6139
6140<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6141<p>See the description
6142 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6143
6144</div>
6145
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6146<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6147<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6148 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6149</h4>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6150
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6151<div>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6152
6153<h5>Syntax:</h5>
6154<pre>
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6155 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]6156</pre>
6157
6158<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6159<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6160 insert a prefetch instruction if supported; otherwise, it is a noop.
6161 Prefetches have no effect on the behavior of the program but can change its
6162 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6163
6164<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6165<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6166 specifier determining if the fetch should be for a read (0) or write (1),
6167 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6168 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6169 specifies whether the prefetch is performed on the data (1) or instruction (0)
6170 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6171 must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6172
6173<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6174<p>This intrinsic does not modify the behavior of the program. In particular,
6175 prefetches cannot trap and do not produce a value. On targets that support
6176 this intrinsic, the prefetch can provide hints to the processor cache for
6177 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6178
6179</div>
6180
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6181<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6182<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6183 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6184</h4>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6185
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6186<div>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6187
6188<h5>Syntax:</h5>
6189<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6190 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6191</pre>
6192
6193<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6194<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6195 Counter (PC) in a region of code to simulators and other tools. The method
6196 is target specific, but it is expected that the marker will use exported
6197 symbols to transmit the PC of the marker. The marker makes no guarantees
6198 that it will remain with any specific instruction after optimizations. It is
6199 possible that the presence of a marker will inhibit optimizations. The
6200 intended use is to be inserted after optimizations to allow correlations of
6201 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6202
6203<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6204<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6205
6206<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6207<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6208 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6209
6210</div>
6211
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6212<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6213<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6214 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6215</h4>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6216
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6217<div>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6218
6219<h5>Syntax:</h5>
6220<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]6221 declare i64 @llvm.readcyclecounter()
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6222</pre>
6223
6224<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6225<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6226 counter register (or similar low latency, high accuracy clocks) on those
6227 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6228 should map to RPCC. As the backing counters overflow quickly (on the order
6229 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6230
6231<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6232<p>When directly supported, reading the cycle counter should not modify any
6233 memory. Implementations are allowed to either return a application specific
6234 value or a system wide value. On backends without support, this is lowered
6235 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6236
6237</div>
6238
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6239</div>
6240
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6241<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6242<h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6243 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6244</h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6245
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6246<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6247
6248<p>LLVM provides intrinsics for a few important standard C library functions.
6249 These intrinsics allow source-language front-ends to pass information about
6250 the alignment of the pointer arguments to the code generator, providing
6251 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6252
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6253<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6254<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6255 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6256</h4>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6257
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6258<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6259
6260<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6261<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]6262 integer bit width and for different address spaces. Not all targets support
6263 all bit widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6264
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6265<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6266 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]6267 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6268 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]6269 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6270</pre>
6271
6272<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6273<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6274 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6275
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6276<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6277 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6278 and the pointers can be in specified address spaces.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6279
6280<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6281
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6282<p>The first argument is a pointer to the destination, the second is a pointer
6283 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6284 number of bytes to copy, the fourth argument is the alignment of the
6285 source and destination locations, and the fifth is a boolean indicating a
6286 volatile access.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6287
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6288<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]6289 then the caller guarantees that both the source and destination pointers are
6290 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6291
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6292<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6293 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6294 The detailed access behavior is not very cleanly specified and it is unwise
6295 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6296
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6297<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6298
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6299<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6300 source location to the destination location, which are not allowed to
6301 overlap. It copies "len" bytes of memory over. If the argument is known to
6302 be aligned to some boundary, this can be specified as the fourth argument,
6303 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6304
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6305</div>
6306
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6307<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6308<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6309 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6310</h4>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6311
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6312<div>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6313
6314<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6315<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]6316 width and for different address space. Not all targets support all bit
6317 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6318
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6319<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6320 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]6321 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6322 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]6323 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6324</pre>
6325
6326<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6327<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6328 source location to the destination location. It is similar to the
6329 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6330 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6331
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6332<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6333 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6334 and the pointers can be in specified address spaces.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6335
6336<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6337
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6338<p>The first argument is a pointer to the destination, the second is a pointer
6339 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6340 number of bytes to copy, the fourth argument is the alignment of the
6341 source and destination locations, and the fifth is a boolean indicating a
6342 volatile access.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6343
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6344<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]6345 then the caller guarantees that the source and destination pointers are
6346 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6347
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6348<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6349 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6350 The detailed access behavior is not very cleanly specified and it is unwise
6351 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6352
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6353<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6354
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6355<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6356 source location to the destination location, which may overlap. It copies
6357 "len" bytes of memory over. If the argument is known to be aligned to some
6358 boundary, this can be specified as the fourth argument, otherwise it should
6359 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6360
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6361</div>
6362
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6363<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6364<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6365 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6366</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6367
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6368<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6369
6370<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6371<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]6372 width and for different address spaces. However, not all targets support all
6373 bit widths.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6374
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6375<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6376 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6377 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6378 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6379 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6380</pre>
6381
6382<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6383<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6384 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6385
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6386<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6387 intrinsic does not return a value and takes extra alignment/volatile
6388 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6389
6390<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6391<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]6392 byte value with which to fill it, the third argument is an integer argument
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6393 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6394 alignment of the destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6395
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6396<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]6397 then the caller guarantees that the destination pointer is aligned to that
6398 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6399
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6400<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6401 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6402 The detailed access behavior is not very cleanly specified and it is unwise
6403 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6404
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6405<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6406<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6407 at the destination location. If the argument is known to be aligned to some
6408 boundary, this can be specified as the fourth argument, otherwise it should
6409 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6410
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6411</div>
6412
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6413<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6414<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6415 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6416</h4>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6417
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6418<div>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6419
6420<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6421<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6422 floating point or vector of floating point type. Not all targets support all
6423 types however.</p>
6424
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6425<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6426 declare float @llvm.sqrt.f32(float %Val)
6427 declare double @llvm.sqrt.f64(double %Val)
6428 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6429 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6430 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6431</pre>
6432
6433<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6434<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6435 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6436 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6437 behavior for negative numbers other than -0.0 (which allows for better
6438 optimization, because there is no need to worry about errno being
6439 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]6440
6441<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6442<p>The argument and return value are floating point numbers of the same
6443 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6444
6445<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6446<p>This function returns the sqrt of the specified operand if it is a
6447 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6448
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6449</div>
6450
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6451<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6452<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6453 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6454</h4>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6455
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6456<div>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6457
6458<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6459<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6460 floating point or vector of floating point type. Not all targets support all
6461 types however.</p>
6462
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6463<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6464 declare float @llvm.powi.f32(float %Val, i32 %power)
6465 declare double @llvm.powi.f64(double %Val, i32 %power)
6466 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6467 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6468 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6469</pre>
6470
6471<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6472<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6473 specified (positive or negative) power. The order of evaluation of
6474 multiplications is not defined. When a vector of floating point type is
6475 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6476
6477<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6478<p>The second argument is an integer power, and the first is a value to raise to
6479 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6480
6481<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6482<p>This function returns the first value raised to the second power with an
6483 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6484
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6485</div>
6486
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6487<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6488<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6489 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6490</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6491
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6492<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6493
6494<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6495<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6496 floating point or vector of floating point type. Not all targets support all
6497 types however.</p>
6498
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6499<pre>
6500 declare float @llvm.sin.f32(float %Val)
6501 declare double @llvm.sin.f64(double %Val)
6502 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6503 declare fp128 @llvm.sin.f128(fp128 %Val)
6504 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6505</pre>
6506
6507<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6508<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6509
6510<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6511<p>The argument and return value are floating point numbers of the same
6512 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6513
6514<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6515<p>This function returns the sine of the specified operand, returning the same
6516 values as the libm <tt>sin</tt> functions would, and handles error conditions
6517 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6518
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6519</div>
6520
6521<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6522<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6523 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6524</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6525
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6526<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6527
6528<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6529<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6530 floating point or vector of floating point type. Not all targets support all
6531 types however.</p>
6532
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6533<pre>
6534 declare float @llvm.cos.f32(float %Val)
6535 declare double @llvm.cos.f64(double %Val)
6536 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6537 declare fp128 @llvm.cos.f128(fp128 %Val)
6538 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6539</pre>
6540
6541<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6542<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6543
6544<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6545<p>The argument and return value are floating point numbers of the same
6546 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6547
6548<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6549<p>This function returns the cosine of the specified operand, returning the same
6550 values as the libm <tt>cos</tt> functions would, and handles error conditions
6551 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6552
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6553</div>
6554
6555<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6556<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6557 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6558</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6559
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6560<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6561
6562<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6563<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6564 floating point or vector of floating point type. Not all targets support all
6565 types however.</p>
6566
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6567<pre>
6568 declare float @llvm.pow.f32(float %Val, float %Power)
6569 declare double @llvm.pow.f64(double %Val, double %Power)
6570 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6571 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6572 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6573</pre>
6574
6575<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6576<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6577 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6578
6579<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6580<p>The second argument is a floating point power, and the first is a value to
6581 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6582
6583<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6584<p>This function returns the first value raised to the second power, returning
6585 the same values as the libm <tt>pow</tt> functions would, and handles error
6586 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6587
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6588</div>
6589
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6590</div>
6591
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]6592<!-- _______________________________________________________________________ -->
6593<h4>
6594 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6595</h4>
6596
6597<div>
6598
6599<h5>Syntax:</h5>
6600<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6601 floating point or vector of floating point type. Not all targets support all
6602 types however.</p>
6603
6604<pre>
6605 declare float @llvm.exp.f32(float %Val)
6606 declare double @llvm.exp.f64(double %Val)
6607 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6608 declare fp128 @llvm.exp.f128(fp128 %Val)
6609 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6610</pre>
6611
6612<h5>Overview:</h5>
6613<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6614
6615<h5>Arguments:</h5>
6616<p>The argument and return value are floating point numbers of the same
6617 type.</p>
6618
6619<h5>Semantics:</h5>
6620<p>This function returns the same values as the libm <tt>exp</tt> functions
6621 would, and handles error conditions in the same way.</p>
6622
6623</div>
6624
6625<!-- _______________________________________________________________________ -->
6626<h4>
6627 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6628</h4>
6629
6630<div>
6631
6632<h5>Syntax:</h5>
6633<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6634 floating point or vector of floating point type. Not all targets support all
6635 types however.</p>
6636
6637<pre>
6638 declare float @llvm.log.f32(float %Val)
6639 declare double @llvm.log.f64(double %Val)
6640 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6641 declare fp128 @llvm.log.f128(fp128 %Val)
6642 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6643</pre>
6644
6645<h5>Overview:</h5>
6646<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6647
6648<h5>Arguments:</h5>
6649<p>The argument and return value are floating point numbers of the same
6650 type.</p>
6651
6652<h5>Semantics:</h5>
6653<p>This function returns the same values as the libm <tt>log</tt> functions
6654 would, and handles error conditions in the same way.</p>
6655
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]6656<h4>
6657 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
6658</h4>
6659
6660<div>
6661
6662<h5>Syntax:</h5>
6663<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
6664 floating point or vector of floating point type. Not all targets support all
6665 types however.</p>
6666
6667<pre>
6668 declare float @llvm.fma.f32(float %a, float %b, float %c)
6669 declare double @llvm.fma.f64(double %a, double %b, double %c)
6670 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
6671 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
6672 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
6673</pre>
6674
6675<h5>Overview:</h5>
Cameron Zwarichabc43e62011-07-08 22:13:55 +0000[diff] [blame]6676<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]6677 operation.</p>
6678
6679<h5>Arguments:</h5>
6680<p>The argument and return value are floating point numbers of the same
6681 type.</p>
6682
6683<h5>Semantics:</h5>
6684<p>This function returns the same values as the libm <tt>fma</tt> functions
6685 would.</p>
6686
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]6687</div>
6688
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6689<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6690<h3>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6691 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6692</h3>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6693
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6694<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6695
6696<p>LLVM provides intrinsics for a few important bit manipulation operations.
6697 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6698
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6699<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6700<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6701 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6702</h4>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6703
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6704<div>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6705
6706<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6707<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6708 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6709
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6710<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6711 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6712 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6713 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6714</pre>
6715
6716<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6717<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6718 values with an even number of bytes (positive multiple of 16 bits). These
6719 are useful for performing operations on data that is not in the target's
6720 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6721
6722<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6723<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6724 and low byte of the input i16 swapped. Similarly,
6725 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6726 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6727 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6728 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6729 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6730 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6731
6732</div>
6733
6734<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6735<h4>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]6736 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6737</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6738
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6739<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6740
6741<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6742<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]6743 width, or on any vector with integer elements. Not all targets support all
6744 bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6745
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6746<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6747 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6748 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6749 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6750 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6751 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6752 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]6753</pre>
6754
6755<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6756<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6757 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6758
6759<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6760<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]6761 integer type, or a vector with integer elements.
6762 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6763
6764<h5>Semantics:</h5>
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6765<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
6766 element of a vector.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6767
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6768</div>
6769
6770<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6771<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6772 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6773</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6774
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6775<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6776
6777<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6778<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]6779 integer bit width, or any vector whose elements are integers. Not all
6780 targets support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6781
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6782<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6783 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6784 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6785 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6786 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6787 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6788 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]6789</pre>
6790
6791<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6792<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6793 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6794
6795<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6796<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]6797 integer type, or any vector type with integer element type.
6798 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6799
6800<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6801<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6802 zeros in a variable, or within each element of the vector if the operation
6803 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]6804 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6805
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6806</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6807
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6808<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6809<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6810 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6811</h4>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6812
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6813<div>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6814
6815<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6816<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]6817 integer bit width, or any vector of integer elements. Not all targets
6818 support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6819
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6820<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6821 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6822 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6823 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6824 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6825 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6826 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]6827</pre>
6828
6829<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6830<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6831 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6832
6833<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6834<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]6835 integer type, or a vectory with integer element type.. The return type
6836 must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6837
6838<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6839<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6840 zeros in a variable, or within each element of a vector.
6841 If the src == 0 then the result is the size in bits of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6842 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6843
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6844</div>
6845
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6846</div>
6847
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6848<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6849<h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6850 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6851</h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6852
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6853<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6854
6855<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6856
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6857<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6858<h4>
6859 <a name="int_sadd_overflow">
6860 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
6861 </a>
6862</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6863
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6864<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6865
6866<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6867<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]6868 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6869
6870<pre>
6871 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6872 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6873 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6874</pre>
6875
6876<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6877<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6878 a signed addition of the two arguments, and indicate whether an overflow
6879 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6880
6881<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6882<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]6883 be of integer types of any bit width, but they must have the same bit
6884 width. The second element of the result structure must be of
6885 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6886 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6887
6888<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6889<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6890 a signed addition of the two variables. They return a structure &mdash; the
6891 first element of which is the signed summation, and the second element of
6892 which is a bit specifying if the signed summation resulted in an
6893 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6894
6895<h5>Examples:</h5>
6896<pre>
6897 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6898 %sum = extractvalue {i32, i1} %res, 0
6899 %obit = extractvalue {i32, i1} %res, 1
6900 br i1 %obit, label %overflow, label %normal
6901</pre>
6902
6903</div>
6904
6905<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6906<h4>
6907 <a name="int_uadd_overflow">
6908 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
6909 </a>
6910</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6911
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6912<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6913
6914<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6915<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]6916 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6917
6918<pre>
6919 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6920 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6921 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6922</pre>
6923
6924<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6925<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6926 an unsigned addition of the two arguments, and indicate whether a carry
6927 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6928
6929<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6930<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]6931 be of integer types of any bit width, but they must have the same bit
6932 width. The second element of the result structure must be of
6933 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6934 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6935
6936<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6937<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6938 an unsigned addition of the two arguments. They return a structure &mdash;
6939 the first element of which is the sum, and the second element of which is a
6940 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6941
6942<h5>Examples:</h5>
6943<pre>
6944 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6945 %sum = extractvalue {i32, i1} %res, 0
6946 %obit = extractvalue {i32, i1} %res, 1
6947 br i1 %obit, label %carry, label %normal
6948</pre>
6949
6950</div>
6951
6952<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6953<h4>
6954 <a name="int_ssub_overflow">
6955 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
6956 </a>
6957</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6958
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6959<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6960
6961<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6962<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]6963 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6964
6965<pre>
6966 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6967 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6968 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6969</pre>
6970
6971<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6972<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6973 a signed subtraction of the two arguments, and indicate whether an overflow
6974 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6975
6976<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6977<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]6978 be of integer types of any bit width, but they must have the same bit
6979 width. The second element of the result structure must be of
6980 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6981 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6982
6983<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6984<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6985 a signed subtraction of the two arguments. They return a structure &mdash;
6986 the first element of which is the subtraction, and the second element of
6987 which is a bit specifying if the signed subtraction resulted in an
6988 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6989
6990<h5>Examples:</h5>
6991<pre>
6992 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6993 %sum = extractvalue {i32, i1} %res, 0
6994 %obit = extractvalue {i32, i1} %res, 1
6995 br i1 %obit, label %overflow, label %normal
6996</pre>
6997
6998</div>
6999
7000<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7001<h4>
7002 <a name="int_usub_overflow">
7003 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
7004 </a>
7005</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7006
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7007<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7008
7009<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7010<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]7011 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7012
7013<pre>
7014 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
7015 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7016 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
7017</pre>
7018
7019<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7020<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7021 an unsigned subtraction of the two arguments, and indicate whether an
7022 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7023
7024<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7025<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]7026 be of integer types of any bit width, but they must have the same bit
7027 width. The second element of the result structure must be of
7028 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7029 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7030
7031<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7032<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7033 an unsigned subtraction of the two arguments. They return a structure &mdash;
7034 the first element of which is the subtraction, and the second element of
7035 which is a bit specifying if the unsigned subtraction resulted in an
7036 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7037
7038<h5>Examples:</h5>
7039<pre>
7040 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7041 %sum = extractvalue {i32, i1} %res, 0
7042 %obit = extractvalue {i32, i1} %res, 1
7043 br i1 %obit, label %overflow, label %normal
7044</pre>
7045
7046</div>
7047
7048<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7049<h4>
7050 <a name="int_smul_overflow">
7051 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
7052 </a>
7053</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7054
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7055<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7056
7057<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7058<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]7059 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7060
7061<pre>
7062 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
7063 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7064 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
7065</pre>
7066
7067<h5>Overview:</h5>
7068
7069<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7070 a signed multiplication of the two arguments, and indicate whether an
7071 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7072
7073<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7074<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]7075 be of integer types of any bit width, but they must have the same bit
7076 width. The second element of the result structure must be of
7077 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7078 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7079
7080<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7081<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7082 a signed multiplication of the two arguments. They return a structure &mdash;
7083 the first element of which is the multiplication, and the second element of
7084 which is a bit specifying if the signed multiplication resulted in an
7085 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7086
7087<h5>Examples:</h5>
7088<pre>
7089 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7090 %sum = extractvalue {i32, i1} %res, 0
7091 %obit = extractvalue {i32, i1} %res, 1
7092 br i1 %obit, label %overflow, label %normal
7093</pre>
7094
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]7095</div>
7096
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7097<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7098<h4>
7099 <a name="int_umul_overflow">
7100 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7101 </a>
7102</h4>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7103
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7104<div>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7105
7106<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7107<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]7108 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7109
7110<pre>
7111 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7112 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7113 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7114</pre>
7115
7116<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7117<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7118 a unsigned multiplication of the two arguments, and indicate whether an
7119 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7120
7121<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7122<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]7123 be of integer types of any bit width, but they must have the same bit
7124 width. The second element of the result structure must be of
7125 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7126 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7127
7128<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7129<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7130 an unsigned multiplication of the two arguments. They return a structure
7131 &mdash; the first element of which is the multiplication, and the second
7132 element of which is a bit specifying if the unsigned multiplication resulted
7133 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7134
7135<h5>Examples:</h5>
7136<pre>
7137 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7138 %sum = extractvalue {i32, i1} %res, 0
7139 %obit = extractvalue {i32, i1} %res, 1
7140 br i1 %obit, label %overflow, label %normal
7141</pre>
7142
7143</div>
7144
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7145</div>
7146
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7147<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7148<h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7149 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7150</h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7151
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7152<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7153
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7154<p>Half precision floating point is a storage-only format. This means that it is
7155 a dense encoding (in memory) but does not support computation in the
7156 format.</p>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7157
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7158<p>This means that code must first load the half-precision floating point
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7159 value as an i16, then convert it to float with <a
7160 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7161 Computation can then be performed on the float value (including extending to
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7162 double etc). To store the value back to memory, it is first converted to
7163 float if needed, then converted to i16 with
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7164 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7165 storing as an i16 value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7166
7167<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7168<h4>
7169 <a name="int_convert_to_fp16">
7170 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7171 </a>
7172</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7173
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7174<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7175
7176<h5>Syntax:</h5>
7177<pre>
7178 declare i16 @llvm.convert.to.fp16(f32 %a)
7179</pre>
7180
7181<h5>Overview:</h5>
7182<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7183 a conversion from single precision floating point format to half precision
7184 floating point format.</p>
7185
7186<h5>Arguments:</h5>
7187<p>The intrinsic function contains single argument - the value to be
7188 converted.</p>
7189
7190<h5>Semantics:</h5>
7191<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7192 a conversion from single precision floating point format to half precision
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7193 floating point format. The return value is an <tt>i16</tt> which
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7194 contains the converted number.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7195
7196<h5>Examples:</h5>
7197<pre>
7198 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7199 store i16 %res, i16* @x, align 2
7200</pre>
7201
7202</div>
7203
7204<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7205<h4>
7206 <a name="int_convert_from_fp16">
7207 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7208 </a>
7209</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7210
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7211<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7212
7213<h5>Syntax:</h5>
7214<pre>
7215 declare f32 @llvm.convert.from.fp16(i16 %a)
7216</pre>
7217
7218<h5>Overview:</h5>
7219<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7220 a conversion from half precision floating point format to single precision
7221 floating point format.</p>
7222
7223<h5>Arguments:</h5>
7224<p>The intrinsic function contains single argument - the value to be
7225 converted.</p>
7226
7227<h5>Semantics:</h5>
7228<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7229 conversion from half single precision floating point format to single
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7230 precision floating point format. The input half-float value is represented by
7231 an <tt>i16</tt> value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7232
7233<h5>Examples:</h5>
7234<pre>
7235 %a = load i16* @x, align 2
7236 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7237</pre>
7238
7239</div>
7240
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7241</div>
7242
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7243<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7244<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7245 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7246</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7247
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7248<div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7249
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7250<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7251 prefix), are described in
7252 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7253 Level Debugging</a> document.</p>
7254
7255</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7256
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7257<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7258<h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7259 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7260</h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7261
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7262<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7263
7264<p>The LLVM exception handling intrinsics (which all start with
7265 <tt>llvm.eh.</tt> prefix), are described in
7266 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7267 Handling</a> document.</p>
7268
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7269</div>
7270
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7271<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7272<h3>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7273 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7274</h3>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7275
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7276<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7277
7278<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]7279 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7280 The result is a callable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7281 function pointer lacking the nest parameter - the caller does not need to
7282 provide a value for it. Instead, the value to use is stored in advance in a
7283 "trampoline", a block of memory usually allocated on the stack, which also
7284 contains code to splice the nest value into the argument list. This is used
7285 to implement the GCC nested function address extension.</p>
7286
7287<p>For example, if the function is
7288 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7289 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7290 follows:</p>
7291
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]7292<pre class="doc_code">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7293 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7294 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7295 %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]7296 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7297</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7298
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7299<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7300 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7301
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7302<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7303<h4>
7304 <a name="int_it">
7305 '<tt>llvm.init.trampoline</tt>' Intrinsic
7306 </a>
7307</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7308
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7309<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7310
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7311<h5>Syntax:</h5>
7312<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7313 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]7314</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7315
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7316<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7317<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7318 function pointer suitable for executing it.</p>
7319
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7320<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7321<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7322 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7323 sufficiently aligned block of memory; this memory is written to by the
7324 intrinsic. Note that the size and the alignment are target-specific - LLVM
7325 currently provides no portable way of determining them, so a front-end that
7326 generates this intrinsic needs to have some target-specific knowledge.
7327 The <tt>func</tt> argument must hold a function bitcast to
7328 an <tt>i8*</tt>.</p>
7329
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7330<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7331<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7332 dependent code, turning it into a function. A pointer to this function is
7333 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7334 function pointer type</a> before being called. The new function's signature
7335 is the same as that of <tt>func</tt> with any arguments marked with
7336 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7337 is allowed, and it must be of pointer type. Calling the new function is
7338 equivalent to calling <tt>func</tt> with the same argument list, but
7339 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7340 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7341 by <tt>tramp</tt> is modified, then the effect of any later call to the
7342 returned function pointer is undefined.</p>
7343
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7344</div>
7345
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7346</div>
7347
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7348<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7349<h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7350 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7351</h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7352
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7353<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7354
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7355<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7356 hardware constructs for atomic operations and memory synchronization. This
7357 provides an interface to the hardware, not an interface to the programmer. It
7358 is aimed at a low enough level to allow any programming models or APIs
7359 (Application Programming Interfaces) which need atomic behaviors to map
7360 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7361 hardware provides a "universal IR" for source languages, it also provides a
7362 starting point for developing a "universal" atomic operation and
7363 synchronization IR.</p>
7364
7365<p>These do <em>not</em> form an API such as high-level threading libraries,
7366 software transaction memory systems, atomic primitives, and intrinsic
7367 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7368 application libraries. The hardware interface provided by LLVM should allow
7369 a clean implementation of all of these APIs and parallel programming models.
7370 No one model or paradigm should be selected above others unless the hardware
7371 itself ubiquitously does so.</p>
7372
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7373<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7374<h4>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7375 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7376</h4>
7377
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7378<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7379<h5>Syntax:</h5>
7380<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7381 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]7382</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7383
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7384<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7385<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7386 specific pairs of memory access types.</p>
7387
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7388<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7389<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7390 The first four arguments enables a specific barrier as listed below. The
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]7391 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7392 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7393
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7394<ul>
7395 <li><tt>ll</tt>: load-load barrier</li>
7396 <li><tt>ls</tt>: load-store barrier</li>
7397 <li><tt>sl</tt>: store-load barrier</li>
7398 <li><tt>ss</tt>: store-store barrier</li>
7399 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7400</ul>
7401
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7402<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7403<p>This intrinsic causes the system to enforce some ordering constraints upon
7404 the loads and stores of the program. This barrier does not
7405 indicate <em>when</em> any events will occur, it only enforces
7406 an <em>order</em> in which they occur. For any of the specified pairs of load
7407 and store operations (f.ex. load-load, or store-load), all of the first
7408 operations preceding the barrier will complete before any of the second
7409 operations succeeding the barrier begin. Specifically the semantics for each
7410 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7411
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7412<ul>
7413 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7414 after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7415 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7416 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7417 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7418 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7419 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7420 load after the barrier begins.</li>
7421</ul>
7422
7423<p>These semantics are applied with a logical "and" behavior when more than one
7424 is enabled in a single memory barrier intrinsic.</p>
7425
7426<p>Backends may implement stronger barriers than those requested when they do
7427 not support as fine grained a barrier as requested. Some architectures do
7428 not need all types of barriers and on such architectures, these become
7429 noops.</p>
7430
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7431<h5>Example:</h5>
7432<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7433%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7434%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7435 store i32 4, %ptr
7436
7437%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0b0669a2011-06-29 17:14:00 +0000[diff] [blame]7438 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]7439 <i>; guarantee the above finishes</i>
7440 store i32 8, %ptr <i>; before this begins</i>
7441</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7442
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7443</div>
7444
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7445<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7446<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7447 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7448</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7449
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7450<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7451
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7452<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7453<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7454 any integer bit width and for different address spaces. Not all targets
7455 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7456
7457<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7458 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7459 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7460 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7461 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]7462</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7463
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7464<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7465<p>This loads a value in memory and compares it to a given value. If they are
7466 equal, it stores a new value into the memory.</p>
7467
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7468<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7469<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7470 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7471 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7472 this integer type. While any bit width integer may be used, targets may only
7473 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7474
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7475<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7476<p>This entire intrinsic must be executed atomically. It first loads the value
7477 in memory pointed to by <tt>ptr</tt> and compares it with the
7478 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7479 memory. The loaded value is yielded in all cases. This provides the
7480 equivalent of an atomic compare-and-swap operation within the SSA
7481 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7482
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7483<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7484<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7485%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7486%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7487 store i32 4, %ptr
7488
7489%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7490%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7491 <i>; yields {i32}:result1 = 4</i>
7492%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7493%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7494
7495%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7496%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7497 <i>; yields {i32}:result2 = 8</i>
7498%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7499
7500%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7501</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7502
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7503</div>
7504
7505<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7506<h4>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7507 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7508</h4>
7509
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7510<div>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7511<h5>Syntax:</h5>
7512
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7513<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7514 integer bit width. Not all targets support all bit widths however.</p>
7515
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7516<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7517 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7518 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7519 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7520 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]7521</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7522
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7523<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7524<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7525 the value from memory. It then stores the value in <tt>val</tt> in the memory
7526 at <tt>ptr</tt>.</p>
7527
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7528<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7529<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7530 the <tt>val</tt> argument and the result must be integers of the same bit
7531 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7532 integer type. The targets may only lower integer representations they
7533 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7534
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7535<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7536<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7537 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7538 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7539
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7540<h5>Examples:</h5>
7541<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7542%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7543%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7544 store i32 4, %ptr
7545
7546%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7547%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7548 <i>; yields {i32}:result1 = 4</i>
7549%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7550%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7551
7552%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7553%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7554 <i>; yields {i32}:result2 = 8</i>
7555
7556%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7557%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7558</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7559
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7560</div>
7561
7562<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7563<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7564 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7565</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7566
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7567<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7568
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7569<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7570<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7571 any integer bit width. Not all targets support all bit widths however.</p>
7572
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7573<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7574 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7575 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7576 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7577 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]7578</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7579
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7580<h5>Overview:</h5>
7581<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7582 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7583
7584<h5>Arguments:</h5>
7585<p>The intrinsic takes two arguments, the first a pointer to an integer value
7586 and the second an integer value. The result is also an integer value. These
7587 integer types can have any bit width, but they must all have the same bit
7588 width. The targets may only lower integer representations they support.</p>
7589
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7590<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7591<p>This intrinsic does a series of operations atomically. It first loads the
7592 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7593 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]7594
7595<h5>Examples:</h5>
7596<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7597%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7598%ptr = bitcast i8* %mallocP to i32*
7599 store i32 4, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7600%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7601 <i>; yields {i32}:result1 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7602%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7603 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7604%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7605 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7606%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7607</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7608
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7609</div>
7610
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7611<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7612<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7613 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7614</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7615
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7616<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7617
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7618<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7619<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7620 any integer bit width and for different address spaces. Not all targets
7621 support all bit widths however.</p>
7622
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7623<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7624 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7625 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7626 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7627 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]7628</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7629
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7630<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7631<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7632 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7633
7634<h5>Arguments:</h5>
7635<p>The intrinsic takes two arguments, the first a pointer to an integer value
7636 and the second an integer value. The result is also an integer value. These
7637 integer types can have any bit width, but they must all have the same bit
7638 width. The targets may only lower integer representations they support.</p>
7639
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7640<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7641<p>This intrinsic does a series of operations atomically. It first loads the
7642 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7643 result to <tt>ptr</tt>. It yields the original value stored
7644 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7645
7646<h5>Examples:</h5>
7647<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7648%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7649%ptr = bitcast i8* %mallocP to i32*
7650 store i32 8, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7651%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7652 <i>; yields {i32}:result1 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7653%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7654 <i>; yields {i32}:result2 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7655%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7656 <i>; yields {i32}:result3 = 2</i>
7657%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7658</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7659
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7660</div>
7661
7662<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7663<h4>
7664 <a name="int_atomic_load_and">
7665 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7666 </a>
7667 <br>
7668 <a name="int_atomic_load_nand">
7669 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7670 </a>
7671 <br>
7672 <a name="int_atomic_load_or">
7673 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7674 </a>
7675 <br>
7676 <a name="int_atomic_load_xor">
7677 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7678 </a>
7679</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7680
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7681<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7682
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7683<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7684<p>These are overloaded intrinsics. You can
7685 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7686 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7687 bit width and for different address spaces. Not all targets support all bit
7688 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7689
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7690<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7691 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7692 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7693 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7694 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]7695</pre>
7696
7697<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7698 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7699 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7700 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7701 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]7702</pre>
7703
7704<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7705 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7706 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7707 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7708 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]7709</pre>
7710
7711<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7712 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7713 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7714 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7715 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]7716</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7717
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7718<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7719<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7720 the value stored in memory at <tt>ptr</tt>. It yields the original value
7721 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7722
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7723<h5>Arguments:</h5>
7724<p>These intrinsics take two arguments, the first a pointer to an integer value
7725 and the second an integer value. The result is also an integer value. These
7726 integer types can have any bit width, but they must all have the same bit
7727 width. The targets may only lower integer representations they support.</p>
7728
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7729<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7730<p>These intrinsics does a series of operations atomically. They first load the
7731 value stored at <tt>ptr</tt>. They then do the bitwise
7732 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7733 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7734
7735<h5>Examples:</h5>
7736<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7737%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7738%ptr = bitcast i8* %mallocP to i32*
7739 store i32 0x0F0F, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7740%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7741 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7742%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7743 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7744%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7745 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7746%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7747 <i>; yields {i32}:result3 = FF</i>
7748%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7749</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7750
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7751</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7752
7753<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7754<h4>
7755 <a name="int_atomic_load_max">
7756 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
7757 </a>
7758 <br>
7759 <a name="int_atomic_load_min">
7760 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
7761 </a>
7762 <br>
7763 <a name="int_atomic_load_umax">
7764 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
7765 </a>
7766 <br>
7767 <a name="int_atomic_load_umin">
7768 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
7769 </a>
7770</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7771
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7772<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7773
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7774<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7775<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7776 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7777 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7778 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7779
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7780<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7781 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7782 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7783 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7784 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]7785</pre>
7786
7787<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7788 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7789 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7790 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7791 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]7792</pre>
7793
7794<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7795 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7796 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7797 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7798 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]7799</pre>
7800
7801<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7802 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7803 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7804 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7805 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]7806</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7807
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7808<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7809<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7810 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7811 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7812
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7813<h5>Arguments:</h5>
7814<p>These intrinsics take two arguments, the first a pointer to an integer value
7815 and the second an integer value. The result is also an integer value. These
7816 integer types can have any bit width, but they must all have the same bit
7817 width. The targets may only lower integer representations they support.</p>
7818
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7819<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7820<p>These intrinsics does a series of operations atomically. They first load the
7821 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7822 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7823 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7824
7825<h5>Examples:</h5>
7826<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7827%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7828%ptr = bitcast i8* %mallocP to i32*
7829 store i32 7, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7830%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7831 <i>; yields {i32}:result0 = 7</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7832%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7833 <i>; yields {i32}:result1 = -2</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7834%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7835 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7836%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7837 <i>; yields {i32}:result3 = 8</i>
7838%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7839</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7840
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7841</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7842
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7843</div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7844
7845<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7846<h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7847 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7848</h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7849
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7850<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7851
7852<p>This class of intrinsics exists to information about the lifetime of memory
7853 objects and ranges where variables are immutable.</p>
7854
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7855<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7856<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7857 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7858</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7859
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7860<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7861
7862<h5>Syntax:</h5>
7863<pre>
7864 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7865</pre>
7866
7867<h5>Overview:</h5>
7868<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7869 object's lifetime.</p>
7870
7871<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7872<p>The first argument is a constant integer representing the size of the
7873 object, or -1 if it is variable sized. The second argument is a pointer to
7874 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7875
7876<h5>Semantics:</h5>
7877<p>This intrinsic indicates that before this point in the code, the value of the
7878 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]7879 never be used and has an undefined value. A load from the pointer that
7880 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7881 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7882
7883</div>
7884
7885<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7886<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7887 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7888</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7889
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7890<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7891
7892<h5>Syntax:</h5>
7893<pre>
7894 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7895</pre>
7896
7897<h5>Overview:</h5>
7898<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7899 object's lifetime.</p>
7900
7901<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7902<p>The first argument is a constant integer representing the size of the
7903 object, or -1 if it is variable sized. The second argument is a pointer to
7904 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7905
7906<h5>Semantics:</h5>
7907<p>This intrinsic indicates that after this point in the code, the value of the
7908 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7909 never be used and has an undefined value. Any stores into the memory object
7910 following this intrinsic may be removed as dead.
7911
7912</div>
7913
7914<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7915<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7916 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7917</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7918
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7919<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7920
7921<h5>Syntax:</h5>
7922<pre>
Nick Lewycky29b6cb42010-11-30 04:13:41 +0000[diff] [blame]7923 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7924</pre>
7925
7926<h5>Overview:</h5>
7927<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7928 a memory object will not change.</p>
7929
7930<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7931<p>The first argument is a constant integer representing the size of the
7932 object, or -1 if it is variable sized. The second argument is a pointer to
7933 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7934
7935<h5>Semantics:</h5>
7936<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7937 the return value, the referenced memory location is constant and
7938 unchanging.</p>
7939
7940</div>
7941
7942<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7943<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7944 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7945</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7946
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7947<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7948
7949<h5>Syntax:</h5>
7950<pre>
7951 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7952</pre>
7953
7954<h5>Overview:</h5>
7955<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7956 a memory object are mutable.</p>
7957
7958<h5>Arguments:</h5>
7959<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7960 The second argument is a constant integer representing the size of the
7961 object, or -1 if it is variable sized and the third argument is a pointer
7962 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7963
7964<h5>Semantics:</h5>
7965<p>This intrinsic indicates that the memory is mutable again.</p>
7966
7967</div>
7968
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7969</div>
7970
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7971<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7972<h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7973 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7974</h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7975
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7976<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7977
7978<p>This class of intrinsics is designed to be generic and has no specific
7979 purpose.</p>
7980
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7981<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7982<h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7983 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7984</h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7985
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7986<div>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7987
7988<h5>Syntax:</h5>
7989<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7990 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]7991</pre>
7992
7993<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7994<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7995
7996<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7997<p>The first argument is a pointer to a value, the second is a pointer to a
7998 global string, the third is a pointer to a global string which is the source
7999 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8000
8001<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8002<p>This intrinsic allows annotation of local variables with arbitrary strings.
8003 This can be useful for special purpose optimizations that want to look for
8004 these annotations. These have no other defined use, they are ignored by code
8005 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8006
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8007</div>
8008
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8009<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8010<h4>
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]8011 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8012</h4>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8013
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8014<div>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8015
8016<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8017<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
8018 any integer bit width.</p>
8019
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8020<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8021 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8022 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8023 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8024 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8025 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]8026</pre>
8027
8028<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8029<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8030
8031<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8032<p>The first argument is an integer value (result of some expression), the
8033 second is a pointer to a global string, the third is a pointer to a global
8034 string which is the source file name, and the last argument is the line
8035 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8036
8037<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8038<p>This intrinsic allows annotations to be put on arbitrary expressions with
8039 arbitrary strings. This can be useful for special purpose optimizations that
8040 want to look for these annotations. These have no other defined use, they
8041 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8042
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8043</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]8044
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8045<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8046<h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8047 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8048</h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8049
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8050<div>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8051
8052<h5>Syntax:</h5>
8053<pre>
8054 declare void @llvm.trap()
8055</pre>
8056
8057<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8058<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8059
8060<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8061<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8062
8063<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8064<p>This intrinsics is lowered to the target dependent trap instruction. If the
8065 target does not have a trap instruction, this intrinsic will be lowered to
8066 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8067
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8068</div>
8069
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8070<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8071<h4>
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]8072 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8073</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8074
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8075<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8076
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8077<h5>Syntax:</h5>
8078<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8079 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8080</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8081
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8082<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8083<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8084 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8085 ensure that it is placed on the stack before local variables.</p>
8086
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8087<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8088<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8089 arguments. The first argument is the value loaded from the stack
8090 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8091 that has enough space to hold the value of the guard.</p>
8092
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8093<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8094<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8095 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8096 stack. This is to ensure that if a local variable on the stack is
8097 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8098 the guard on the stack is checked against the original guard. If they are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8099 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8100 function.</p>
8101
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8102</div>
8103
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8104<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8105<h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8106 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8107</h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8108
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8109<div>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8110
8111<h5>Syntax:</h5>
8112<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8113 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8114 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8115</pre>
8116
8117<h5>Overview:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8118<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8119 the optimizers to determine at compile time whether a) an operation (like
8120 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8121 runtime check for overflow isn't necessary. An object in this context means
8122 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8123
8124<h5>Arguments:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8125<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]8126 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8127 is a boolean 0 or 1. This argument determines whether you want the
8128 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]8129 1, variables are not allowed.</p>
8130
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8131<h5>Semantics:</h5>
8132<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8133 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8134 depending on the <tt>type</tt> argument, if the size cannot be determined at
8135 compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8136
8137</div>
8138
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Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8145<address>
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8151 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]8152 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8153 Last modified: $Date$
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