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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / ce99fa9e26027a21a4552d0d39f17853649833a9 / . / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
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>
27 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
28 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
29 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
30 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
31 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
32 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
33 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
Chris Lattner5a2d8752009-10-10 18:26:06 +0000[diff] [blame]34 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling987e7eb2009-07-20 02:41:50 +0000[diff] [blame]35 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
36 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
37 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
38 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]39 </ol>
40 </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]41 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]42 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]43 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]44 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]45 <li><a href="#aliasstructure">Aliases</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]46 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]47 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]48 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]49 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]50 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]51 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]52 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]53 <li><a href="#volatile">Volatile Memory Accesses</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]54 </ol>
55 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]56 <li><a href="#typesystem">Type System</a>
57 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]58 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]59 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]60 <ol>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]61 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]62 <li><a href="#t_floating">Floating Point Types</a></li>
63 <li><a href="#t_void">Void Type</a></li>
64 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]65 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]66 </ol>
67 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]68 <li><a href="#t_derived">Derived Types</a>
69 <ol>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]70 <li><a href="#t_aggregate">Aggregate Types</a>
71 <ol>
72 <li><a href="#t_array">Array Type</a></li>
73 <li><a href="#t_struct">Structure Type</a></li>
74 <li><a href="#t_pstruct">Packed Structure Type</a></li>
75 <li><a href="#t_union">Union Type</a></li>
76 <li><a href="#t_vector">Vector Type</a></li>
77 </ol>
78 </li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]79 <li><a href="#t_function">Function Type</a></li>
80 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]81 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]82 </ol>
83 </li>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]84 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]85 </ol>
86 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]87 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]88 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]89 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]90 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]91 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
92 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]93 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]94 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]95 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]96 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]97 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]98 <li><a href="#othervalues">Other Values</a>
99 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]100 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]101 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]102 </ol>
103 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]104 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
105 <ol>
106 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]107 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
108 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]109 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
110 Global Variable</a></li>
111 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
112 Global Variable</a></li>
113 </ol>
114 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]115 <li><a href="#instref">Instruction Reference</a>
116 <ol>
117 <li><a href="#terminators">Terminator Instructions</a>
118 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]119 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
120 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]121 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]122 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]123 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]124 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]125 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]126 </ol>
127 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]128 <li><a href="#binaryops">Binary Operations</a>
129 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]130 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]131 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]132 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]133 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]134 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]135 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]136 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
137 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
138 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]139 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
140 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
141 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]142 </ol>
143 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]144 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
145 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]146 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
147 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
148 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]149 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]150 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]151 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]152 </ol>
153 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]154 <li><a href="#vectorops">Vector Operations</a>
155 <ol>
156 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
157 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
158 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]159 </ol>
160 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]161 <li><a href="#aggregateops">Aggregate Operations</a>
162 <ol>
163 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
164 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
165 </ol>
166 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]167 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]168 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]169 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]170 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
171 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
172 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]173 </ol>
174 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]175 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]176 <ol>
177 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
178 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
179 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
180 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
181 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]182 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
183 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
184 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
185 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]186 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
187 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]188 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]189 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]190 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]191 <li><a href="#otherops">Other Operations</a>
192 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]193 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
194 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]195 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]196 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]197 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]198 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]199 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]200 </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 Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]203 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]204 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]205 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
206 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]207 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
208 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
209 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]210 </ol>
211 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]212 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
213 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]214 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
215 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
216 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]217 </ol>
218 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]219 <li><a href="#int_codegen">Code Generator Intrinsics</a>
220 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]221 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
222 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
223 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
224 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
225 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
226 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
227 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]228 </ol>
229 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]230 <li><a href="#int_libc">Standard C Library Intrinsics</a>
231 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]232 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
233 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
234 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
235 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]237 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
238 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
239 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]240 </ol>
241 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]242 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]243 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]244 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]245 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
246 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
247 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]248 </ol>
249 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]250 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
251 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]252 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
253 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
254 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
255 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
256 <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]257 <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]258 </ol>
259 </li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]260 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
261 <ol>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]262 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
263 <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]264 </ol>
265 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]266 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]267 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]268 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]269 <ol>
270 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]271 </ol>
272 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]273 <li><a href="#int_atomics">Atomic intrinsics</a>
274 <ol>
275 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
276 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
277 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
278 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
279 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
280 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
281 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
282 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
283 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
284 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
285 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
286 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
287 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
288 </ol>
289 </li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]290 <li><a href="#int_memorymarkers">Memory Use Markers</a>
291 <ol>
292 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
293 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
294 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
295 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
296 </ol>
297 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]298 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]299 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]300 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]301 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]302 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]303 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]304 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]305 '<tt>llvm.trap</tt>' Intrinsic</a></li>
306 <li><a href="#int_stackprotector">
307 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]308 <li><a href="#int_objectsize">
309 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]310 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]311 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]312 </ol>
313 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]314</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]315
316<div class="doc_author">
317 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
318 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]319</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]320
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]321<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]322<div class="doc_section"> <a name="abstract">Abstract </a></div>
323<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]324
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]325<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]326
327<p>This document is a reference manual for the LLVM assembly language. LLVM is
328 a Static Single Assignment (SSA) based representation that provides type
329 safety, low-level operations, flexibility, and the capability of representing
330 'all' high-level languages cleanly. It is the common code representation
331 used throughout all phases of the LLVM compilation strategy.</p>
332
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]333</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]334
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]335<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]336<div class="doc_section"> <a name="introduction">Introduction</a> </div>
337<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]338
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]339<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]340
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]341<p>The LLVM code representation is designed to be used in three different forms:
342 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
343 for fast loading by a Just-In-Time compiler), and as a human readable
344 assembly language representation. This allows LLVM to provide a powerful
345 intermediate representation for efficient compiler transformations and
346 analysis, while providing a natural means to debug and visualize the
347 transformations. The three different forms of LLVM are all equivalent. This
348 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]349
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]350<p>The LLVM representation aims to be light-weight and low-level while being
351 expressive, typed, and extensible at the same time. It aims to be a
352 "universal IR" of sorts, by being at a low enough level that high-level ideas
353 may be cleanly mapped to it (similar to how microprocessors are "universal
354 IR's", allowing many source languages to be mapped to them). By providing
355 type information, LLVM can be used as the target of optimizations: for
356 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]357 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]358 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]359
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]360</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]361
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]362<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]363<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]364
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]365<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]366
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]367<p>It is important to note that this document describes 'well formed' LLVM
368 assembly language. There is a difference between what the parser accepts and
369 what is considered 'well formed'. For example, the following instruction is
370 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]371
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]372<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]373<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]374%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]375</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]376</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]377
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]378<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
379 LLVM infrastructure provides a verification pass that may be used to verify
380 that an LLVM module is well formed. This pass is automatically run by the
381 parser after parsing input assembly and by the optimizer before it outputs
382 bitcode. The violations pointed out by the verifier pass indicate bugs in
383 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]384
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]385</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]386
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]387<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]388
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]389<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]390<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]391<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]392
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]393<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]394
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]395<p>LLVM identifiers come in two basic types: global and local. Global
396 identifiers (functions, global variables) begin with the <tt>'@'</tt>
397 character. Local identifiers (register names, types) begin with
398 the <tt>'%'</tt> character. Additionally, there are three different formats
399 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]400
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]401<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]402 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]403 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
404 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
405 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
406 other characters in their names can be surrounded with quotes. Special
407 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
408 ASCII code for the character in hexadecimal. In this way, any character
409 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]410
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]411 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]412 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]413
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]414 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]415 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]416</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]417
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]418<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]419 don't need to worry about name clashes with reserved words, and the set of
420 reserved words may be expanded in the future without penalty. Additionally,
421 unnamed identifiers allow a compiler to quickly come up with a temporary
422 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]423
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]424<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]425 languages. There are keywords for different opcodes
426 ('<tt><a href="#i_add">add</a></tt>',
427 '<tt><a href="#i_bitcast">bitcast</a></tt>',
428 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
429 ('<tt><a href="#t_void">void</a></tt>',
430 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
431 reserved words cannot conflict with variable names, because none of them
432 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]433
434<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]435 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]436
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]437<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]438
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]439<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]440<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]441%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]442</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]443</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]444
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]445<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]446
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]447<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]448<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]449%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]450</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]451</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]452
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]453<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]454
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]455<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]456<pre>
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>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]461</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]462
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]463<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
464 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]465
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]466<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]467 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]468 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]469
470 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]471 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]472
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]473 <li>Unnamed temporaries are numbered sequentially</li>
474</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]475
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]476<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]477 demonstrating instructions, we will follow an instruction with a comment that
478 defines the type and name of value produced. Comments are shown in italic
479 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]480
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]481</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]482
483<!-- *********************************************************************** -->
484<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
485<!-- *********************************************************************** -->
486
487<!-- ======================================================================= -->
488<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
489</div>
490
491<div class="doc_text">
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
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]500<div class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]501<pre>
502<i>; Declare the string constant as a global constant.</i>
503<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]504
505<i>; External declaration of the puts function</i>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]506<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]507
508<i>; Definition of main function</i>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]509define i32 @main() { <i>; i32()* </i>
510 <i>; Convert [13 x i8]* to i8 *...</i>
511 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]512
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]513 <i>; Call puts function to write out the string to stdout.</i>
514 <a href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]515 <a href="#i_ret">ret</a> i32 0<br>}
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>
521</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]522
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]523<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]524 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]525 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]526 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
527 "<tt>foo"</tt>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]528
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]529<p>In general, a module is made up of a list of global values, where both
530 functions and global variables are global values. Global values are
531 represented by a pointer to a memory location (in this case, a pointer to an
532 array of char, and a pointer to a function), and have one of the
533 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]534
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]535</div>
536
537<!-- ======================================================================= -->
538<div class="doc_subsection">
539 <a name="linkage">Linkage Types</a>
540</div>
541
542<div class="doc_text">
543
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]544<p>All Global Variables and Functions have one of the following types of
545 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]546
547<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]548 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]549 <dd>Global values with private linkage are only directly accessible by objects
550 in the current module. In particular, linking code into a module with an
551 private global value may cause the private to be renamed as necessary to
552 avoid collisions. Because the symbol is private to the module, all
553 references can be updated. This doesn't show up in any symbol table in the
554 object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]555
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]556 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]557 <dd>Similar to private, but the symbol is passed through the assembler and
Chris Lattnere1eaf912009-08-24 04:32:16 +0000[diff] [blame]558 removed by the linker after evaluation. Note that (unlike private
559 symbols) linker_private symbols are subject to coalescing by the linker:
560 weak symbols get merged and redefinitions are rejected. However, unlike
561 normal strong symbols, they are removed by the linker from the final
562 linked image (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]563
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]564 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]565 <dd>Similar to private, but the value shows as a local symbol
566 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
567 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]568
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]569 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]570 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]571 into the object file corresponding to the LLVM module. They exist to
572 allow inlining and other optimizations to take place given knowledge of
573 the definition of the global, which is known to be somewhere outside the
574 module. Globals with <tt>available_externally</tt> linkage are allowed to
575 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
576 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]577
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]578 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]579 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]580 the same name when linkage occurs. This can be used to implement
581 some forms of inline functions, templates, or other code which must be
582 generated in each translation unit that uses it, but where the body may
583 be overridden with a more definitive definition later. Unreferenced
584 <tt>linkonce</tt> globals are allowed to be discarded. Note that
585 <tt>linkonce</tt> linkage does not actually allow the optimizer to
586 inline the body of this function into callers because it doesn't know if
587 this definition of the function is the definitive definition within the
588 program or whether it will be overridden by a stronger definition.
589 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
590 linkage.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]591
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]592 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]593 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
594 <tt>linkonce</tt> linkage, except that unreferenced globals with
595 <tt>weak</tt> linkage may not be discarded. This is used for globals that
596 are declared "weak" in C source code.</dd>
597
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]598 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]599 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
600 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
601 global scope.
602 Symbols with "<tt>common</tt>" linkage are merged in the same way as
603 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]604 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]605 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]606 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
607 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]608
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]609
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]610 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]611 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]612 pointer to array type. When two global variables with appending linkage
613 are linked together, the two global arrays are appended together. This is
614 the LLVM, typesafe, equivalent of having the system linker append together
615 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]616
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]617 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]618 <dd>The semantics of this linkage follow the ELF object file model: the symbol
619 is weak until linked, if not linked, the symbol becomes null instead of
620 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]621
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]622 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
623 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]624 <dd>Some languages allow differing globals to be merged, such as two functions
625 with different semantics. Other languages, such as <tt>C++</tt>, ensure
626 that only equivalent globals are ever merged (the "one definition rule" -
627 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
628 and <tt>weak_odr</tt> linkage types to indicate that the global will only
629 be merged with equivalent globals. These linkage types are otherwise the
630 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]631
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]632 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]633 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]634 visible, meaning that it participates in linkage and can be used to
635 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]636</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]637
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]638<p>The next two types of linkage are targeted for Microsoft Windows platform
639 only. They are designed to support importing (exporting) symbols from (to)
640 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]641
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]642<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]643 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]644 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]645 or variable via a global pointer to a pointer that is set up by the DLL
646 exporting the symbol. On Microsoft Windows targets, the pointer name is
647 formed by combining <code>__imp_</code> and the function or variable
648 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]649
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]650 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]651 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]652 pointer to a pointer in a DLL, so that it can be referenced with the
653 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
654 name is formed by combining <code>__imp_</code> and the function or
655 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]656</dl>
657
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]658<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
659 another module defined a "<tt>.LC0</tt>" variable and was linked with this
660 one, one of the two would be renamed, preventing a collision. Since
661 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
662 declarations), they are accessible outside of the current module.</p>
663
664<p>It is illegal for a function <i>declaration</i> to have any linkage type
665 other than "externally visible", <tt>dllimport</tt>
666 or <tt>extern_weak</tt>.</p>
667
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]668<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]669 or <tt>weak_odr</tt> linkages.</p>
670
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]671</div>
672
673<!-- ======================================================================= -->
674<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]675 <a name="callingconv">Calling Conventions</a>
676</div>
677
678<div class="doc_text">
679
680<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]681 and <a href="#i_invoke">invokes</a> can all have an optional calling
682 convention specified for the call. The calling convention of any pair of
683 dynamic caller/callee must match, or the behavior of the program is
684 undefined. The following calling conventions are supported by LLVM, and more
685 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]686
687<dl>
688 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]689 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]690 specified) matches the target C calling conventions. This calling
691 convention supports varargs function calls and tolerates some mismatch in
692 the declared prototype and implemented declaration of the function (as
693 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]694
695 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]696 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]697 (e.g. by passing things in registers). This calling convention allows the
698 target to use whatever tricks it wants to produce fast code for the
699 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]700 (Application Binary Interface).
701 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]702 when this or the GHC convention is used.</a> This calling convention
703 does not support varargs and requires the prototype of all callees to
704 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]705
706 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]707 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]708 as possible under the assumption that the call is not commonly executed.
709 As such, these calls often preserve all registers so that the call does
710 not break any live ranges in the caller side. This calling convention
711 does not support varargs and requires the prototype of all callees to
712 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]713
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]714 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
715 <dd>This calling convention has been implemented specifically for use by the
716 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
717 It passes everything in registers, going to extremes to achieve this by
718 disabling callee save registers. This calling convention should not be
719 used lightly but only for specific situations such as an alternative to
720 the <em>register pinning</em> performance technique often used when
721 implementing functional programming languages.At the moment only X86
722 supports this convention and it has the following limitations:
723 <ul>
724 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
725 floating point types are supported.</li>
726 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
727 6 floating point parameters.</li>
728 </ul>
729 This calling convention supports
730 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
731 requires both the caller and callee are using it.
732 </dd>
733
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]734 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]735 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]736 target-specific calling conventions to be used. Target specific calling
737 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]738</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]739
740<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]741 support Pascal conventions or any other well-known target-independent
742 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]743
744</div>
745
746<!-- ======================================================================= -->
747<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]748 <a name="visibility">Visibility Styles</a>
749</div>
750
751<div class="doc_text">
752
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]753<p>All Global Variables and Functions have one of the following visibility
754 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]755
756<dl>
757 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]758 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]759 that the declaration is visible to other modules and, in shared libraries,
760 means that the declared entity may be overridden. On Darwin, default
761 visibility means that the declaration is visible to other modules. Default
762 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]763
764 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]765 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]766 object if they are in the same shared object. Usually, hidden visibility
767 indicates that the symbol will not be placed into the dynamic symbol
768 table, so no other module (executable or shared library) can reference it
769 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]770
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]771 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]772 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]773 the dynamic symbol table, but that references within the defining module
774 will bind to the local symbol. That is, the symbol cannot be overridden by
775 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]776</dl>
777
778</div>
779
780<!-- ======================================================================= -->
781<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]782 <a name="namedtypes">Named Types</a>
783</div>
784
785<div class="doc_text">
786
787<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]788 it easier to read the IR and make the IR more condensed (particularly when
789 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]790
791<div class="doc_code">
792<pre>
793%mytype = type { %mytype*, i32 }
794</pre>
795</div>
796
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]797<p>You may give a name to any <a href="#typesystem">type</a> except
798 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
799 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]800
801<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]802 and that you can therefore specify multiple names for the same type. This
803 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
804 uses structural typing, the name is not part of the type. When printing out
805 LLVM IR, the printer will pick <em>one name</em> to render all types of a
806 particular shape. This means that if you have code where two different
807 source types end up having the same LLVM type, that the dumper will sometimes
808 print the "wrong" or unexpected type. This is an important design point and
809 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]810
811</div>
812
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]813<!-- ======================================================================= -->
814<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]815 <a name="globalvars">Global Variables</a>
816</div>
817
818<div class="doc_text">
819
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]820<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]821 instead of run-time. Global variables may optionally be initialized, may
822 have an explicit section to be placed in, and may have an optional explicit
823 alignment specified. A variable may be defined as "thread_local", which
824 means that it will not be shared by threads (each thread will have a
825 separated copy of the variable). A variable may be defined as a global
826 "constant," which indicates that the contents of the variable
827 will <b>never</b> be modified (enabling better optimization, allowing the
828 global data to be placed in the read-only section of an executable, etc).
829 Note that variables that need runtime initialization cannot be marked
830 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]831
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]832<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
833 constant, even if the final definition of the global is not. This capability
834 can be used to enable slightly better optimization of the program, but
835 requires the language definition to guarantee that optimizations based on the
836 'constantness' are valid for the translation units that do not include the
837 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]838
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]839<p>As SSA values, global variables define pointer values that are in scope
840 (i.e. they dominate) all basic blocks in the program. Global variables
841 always define a pointer to their "content" type because they describe a
842 region of memory, and all memory objects in LLVM are accessed through
843 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]844
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]845<p>A global variable may be declared to reside in a target-specific numbered
846 address space. For targets that support them, address spaces may affect how
847 optimizations are performed and/or what target instructions are used to
848 access the variable. The default address space is zero. The address space
849 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]850
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]851<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]852 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]853
Chris Lattnerce99fa92010-04-28 00:13:42 +0000[diff] [blame^]854<p>An explicit alignment may be specified for a global, which must be a power
855 of 2. If not present, or if the alignment is set to zero, the alignment of
856 the global is set by the target to whatever it feels convenient. If an
857 explicit alignment is specified, the global is forced to have exactly that
858 alignment. Targets are not allowed to over-align the global in cases where
859 it is observable: for example, overaligning a global is observable if it has
860 an assigned section and higher alignment could cause holes between
861 consequtive globals.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]862
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]863<p>For example, the following defines a global in a numbered address space with
864 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]865
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]866<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]867<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]868@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]869</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]870</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]871
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]872</div>
873
874
875<!-- ======================================================================= -->
876<div class="doc_subsection">
877 <a name="functionstructure">Functions</a>
878</div>
879
880<div class="doc_text">
881
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]882<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]883 optional <a href="#linkage">linkage type</a>, an optional
884 <a href="#visibility">visibility style</a>, an optional
885 <a href="#callingconv">calling convention</a>, a return type, an optional
886 <a href="#paramattrs">parameter attribute</a> for the return type, a function
887 name, a (possibly empty) argument list (each with optional
888 <a href="#paramattrs">parameter attributes</a>), optional
889 <a href="#fnattrs">function attributes</a>, an optional section, an optional
890 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
891 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]892
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]893<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
894 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]895 <a href="#visibility">visibility style</a>, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]896 <a href="#callingconv">calling convention</a>, a return type, an optional
897 <a href="#paramattrs">parameter attribute</a> for the return type, a function
898 name, a possibly empty list of arguments, an optional alignment, and an
899 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]900
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]901<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]902 (Control Flow Graph) for the function. Each basic block may optionally start
903 with a label (giving the basic block a symbol table entry), contains a list
904 of instructions, and ends with a <a href="#terminators">terminator</a>
905 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]906
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]907<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]908 executed on entrance to the function, and it is not allowed to have
909 predecessor basic blocks (i.e. there can not be any branches to the entry
910 block of a function). Because the block can have no predecessors, it also
911 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]912
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]913<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]914 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]915
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]916<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]917 the alignment is set to zero, the alignment of the function is set by the
918 target to whatever it feels convenient. If an explicit alignment is
919 specified, the function is forced to have at least that much alignment. All
920 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]921
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]922<h5>Syntax:</h5>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]923<div class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]924<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]925define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]926 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
927 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
928 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
929 [<a href="#gc">gc</a>] { ... }
930</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]931</div>
932
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]933</div>
934
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]935<!-- ======================================================================= -->
936<div class="doc_subsection">
937 <a name="aliasstructure">Aliases</a>
938</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]939
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]940<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]941
942<p>Aliases act as "second name" for the aliasee value (which can be either
943 function, global variable, another alias or bitcast of global value). Aliases
944 may have an optional <a href="#linkage">linkage type</a>, and an
945 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]946
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]947<h5>Syntax:</h5>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]948<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]949<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]950@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]951</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]952</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]953
954</div>
955
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]956<!-- ======================================================================= -->
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]957<div class="doc_subsection">
958 <a name="namedmetadatastructure">Named Metadata</a>
959</div>
960
961<div class="doc_text">
962
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]963<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
964 nodes</a> (but not metadata strings) and null are the only valid operands for
965 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]966
967<h5>Syntax:</h5>
968<div class="doc_code">
969<pre>
970!1 = metadata !{metadata !"one"}
971!name = !{null, !1}
972</pre>
973</div>
974
975</div>
976
977<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]978<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]979
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]980<div class="doc_text">
981
982<p>The return type and each parameter of a function type may have a set of
983 <i>parameter attributes</i> associated with them. Parameter attributes are
984 used to communicate additional information about the result or parameters of
985 a function. Parameter attributes are considered to be part of the function,
986 not of the function type, so functions with different parameter attributes
987 can have the same function type.</p>
988
989<p>Parameter attributes are simple keywords that follow the type specified. If
990 multiple parameter attributes are needed, they are space separated. For
991 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]992
993<div class="doc_code">
994<pre>
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]995declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]996declare i32 @atoi(i8 zeroext)
997declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]998</pre>
999</div>
1000
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1001<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1002 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1003
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1004<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1005
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1006<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1007 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1008 <dd>This indicates to the code generator that the parameter or return value
1009 should be zero-extended to a 32-bit value by the caller (for a parameter)
1010 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1011
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1012 <dt><tt><b>signext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1013 <dd>This indicates to the code generator that the parameter or return value
1014 should be sign-extended to a 32-bit value by the caller (for a parameter)
1015 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1016
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1017 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1018 <dd>This indicates that this parameter or return value should be treated in a
1019 special target-dependent fashion during while emitting code for a function
1020 call or return (usually, by putting it in a register as opposed to memory,
1021 though some targets use it to distinguish between two different kinds of
1022 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1023
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1024 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1025 <dd>This indicates that the pointer parameter should really be passed by value
1026 to the function. The attribute implies that a hidden copy of the pointee
1027 is made between the caller and the callee, so the callee is unable to
1028 modify the value in the callee. This attribute is only valid on LLVM
1029 pointer arguments. It is generally used to pass structs and arrays by
1030 value, but is also valid on pointers to scalars. The copy is considered
1031 to belong to the caller not the callee (for example,
1032 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1033 <tt>byval</tt> parameters). This is not a valid attribute for return
1034 values. The byval attribute also supports specifying an alignment with
1035 the align attribute. This has a target-specific effect on the code
1036 generator that usually indicates a desired alignment for the synthesized
1037 stack slot.</dd>
1038
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1039 <dt><tt><b>sret</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1040 <dd>This indicates that the pointer parameter specifies the address of a
1041 structure that is the return value of the function in the source program.
1042 This pointer must be guaranteed by the caller to be valid: loads and
1043 stores to the structure may be assumed by the callee to not to trap. This
1044 may only be applied to the first parameter. This is not a valid attribute
1045 for return values. </dd>
1046
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1047 <dt><tt><b>noalias</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1048 <dd>This indicates that the pointer does not alias any global or any other
1049 parameter. The caller is responsible for ensuring that this is the
1050 case. On a function return value, <tt>noalias</tt> additionally indicates
1051 that the pointer does not alias any other pointers visible to the
1052 caller. For further details, please see the discussion of the NoAlias
1053 response in
1054 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
1055 analysis</a>.</dd>
1056
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1057 <dt><tt><b>nocapture</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1058 <dd>This indicates that the callee does not make any copies of the pointer
1059 that outlive the callee itself. This is not a valid attribute for return
1060 values.</dd>
1061
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1062 <dt><tt><b>nest</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1063 <dd>This indicates that the pointer parameter can be excised using the
1064 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1065 attribute for return values.</dd>
1066</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1067
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1068</div>
1069
1070<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1071<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1072 <a name="gc">Garbage Collector Names</a>
1073</div>
1074
1075<div class="doc_text">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1076
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1077<p>Each function may specify a garbage collector name, which is simply a
1078 string:</p>
1079
1080<div class="doc_code">
1081<pre>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1082define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1083</pre>
1084</div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1085
1086<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1087 collector which will cause the compiler to alter its output in order to
1088 support the named garbage collection algorithm.</p>
1089
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1090</div>
1091
1092<!-- ======================================================================= -->
1093<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1094 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1095</div>
1096
1097<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1098
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1099<p>Function attributes are set to communicate additional information about a
1100 function. Function attributes are considered to be part of the function, not
1101 of the function type, so functions with different parameter attributes can
1102 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1103
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1104<p>Function attributes are simple keywords that follow the type specified. If
1105 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1106
1107<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1108<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1109define void @f() noinline { ... }
1110define void @f() alwaysinline { ... }
1111define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1112define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1113</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1114</div>
1115
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1116<dl>
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1117 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1118 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1119 the backend should forcibly align the stack pointer. Specify the
1120 desired alignment, which must be a power of two, in parentheses.
1121
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1122 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1123 <dd>This attribute indicates that the inliner should attempt to inline this
1124 function into callers whenever possible, ignoring any active inlining size
1125 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1126
Jakob Stoklund Olesen570a4a52010-02-06 01:16:28 +0000[diff] [blame]1127 <dt><tt><b>inlinehint</b></tt></dt>
1128 <dd>This attribute indicates that the source code contained a hint that inlining
1129 this function is desirable (such as the "inline" keyword in C/C++). It
1130 is just a hint; it imposes no requirements on the inliner.</dd>
1131
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1132 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1133 <dd>This attribute indicates that the inliner should never inline this
1134 function in any situation. This attribute may not be used together with
1135 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1136
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1137 <dt><tt><b>optsize</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1138 <dd>This attribute suggests that optimization passes and code generator passes
1139 make choices that keep the code size of this function low, and otherwise
1140 do optimizations specifically to reduce code size.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1141
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1142 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1143 <dd>This function attribute indicates that the function never returns
1144 normally. This produces undefined behavior at runtime if the function
1145 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1146
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1147 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1148 <dd>This function attribute indicates that the function never returns with an
1149 unwind or exceptional control flow. If the function does unwind, its
1150 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1151
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1152 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1153 <dd>This attribute indicates that the function computes its result (or decides
1154 to unwind an exception) based strictly on its arguments, without
1155 dereferencing any pointer arguments or otherwise accessing any mutable
1156 state (e.g. memory, control registers, etc) visible to caller functions.
1157 It does not write through any pointer arguments
1158 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1159 changes any state visible to callers. This means that it cannot unwind
1160 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1161 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1162
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1163 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1164 <dd>This attribute indicates that the function does not write through any
1165 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1166 arguments) or otherwise modify any state (e.g. memory, control registers,
1167 etc) visible to caller functions. It may dereference pointer arguments
1168 and read state that may be set in the caller. A readonly function always
1169 returns the same value (or unwinds an exception identically) when called
1170 with the same set of arguments and global state. It cannot unwind an
1171 exception by calling the <tt>C++</tt> exception throwing methods, but may
1172 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1173
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1174 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1175 <dd>This attribute indicates that the function should emit a stack smashing
1176 protector. It is in the form of a "canary"&mdash;a random value placed on
1177 the stack before the local variables that's checked upon return from the
1178 function to see if it has been overwritten. A heuristic is used to
1179 determine if a function needs stack protectors or not.<br>
1180<br>
1181 If a function that has an <tt>ssp</tt> attribute is inlined into a
1182 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1183 function will have an <tt>ssp</tt> attribute.</dd>
1184
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1185 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1186 <dd>This attribute indicates that the function should <em>always</em> emit a
1187 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1188 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1189<br>
1190 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1191 function that doesn't have an <tt>sspreq</tt> attribute or which has
1192 an <tt>ssp</tt> attribute, then the resulting function will have
1193 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1194
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1195 <dt><tt><b>noredzone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1196 <dd>This attribute indicates that the code generator should not use a red
1197 zone, even if the target-specific ABI normally permits it.</dd>
1198
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1199 <dt><tt><b>noimplicitfloat</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1200 <dd>This attributes disables implicit floating point instructions.</dd>
1201
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1202 <dt><tt><b>naked</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1203 <dd>This attribute disables prologue / epilogue emission for the function.
1204 This can have very system-specific consequences.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1205</dl>
1206
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1207</div>
1208
1209<!-- ======================================================================= -->
1210<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1211 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1212</div>
1213
1214<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1215
1216<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1217 the GCC "file scope inline asm" blocks. These blocks are internally
1218 concatenated by LLVM and treated as a single unit, but may be separated in
1219 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1220
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1221<div class="doc_code">
1222<pre>
1223module asm "inline asm code goes here"
1224module asm "more can go here"
1225</pre>
1226</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1227
1228<p>The strings can contain any character by escaping non-printable characters.
1229 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]1230 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1231
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1232<p>The inline asm code is simply printed to the machine code .s file when
1233 assembly code is generated.</p>
1234
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1235</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1236
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1237<!-- ======================================================================= -->
1238<div class="doc_subsection">
1239 <a name="datalayout">Data Layout</a>
1240</div>
1241
1242<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1243
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1244<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1245 data is to be laid out in memory. The syntax for the data layout is
1246 simply:</p>
1247
1248<div class="doc_code">
1249<pre>
1250target datalayout = "<i>layout specification</i>"
1251</pre>
1252</div>
1253
1254<p>The <i>layout specification</i> consists of a list of specifications
1255 separated by the minus sign character ('-'). Each specification starts with
1256 a letter and may include other information after the letter to define some
1257 aspect of the data layout. The specifications accepted are as follows:</p>
1258
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1259<dl>
1260 <dt><tt>E</tt></dt>
1261 <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]1262 bits with the most significance have the lowest address location.</dd>
1263
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1264 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1265 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1266 the bits with the least significance have the lowest address
1267 location.</dd>
1268
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1269 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1270 <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]1271 <i>preferred</i> alignments. All sizes are in bits. Specifying
1272 the <i>pref</i> alignment is optional. If omitted, the
1273 preceding <tt>:</tt> should be omitted too.</dd>
1274
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1275 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1276 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1277 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1278
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1279 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1280 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1281 <i>size</i>.</dd>
1282
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1283 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1284 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1285 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1286 (double).</dd>
1287
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1288 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1289 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1290 <i>size</i>.</dd>
1291
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1292 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1293 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1294 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1295
1296 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1297 <dd>This specifies a set of native integer widths for the target CPU
1298 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1299 "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]1300 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1301 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1302</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1303
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1304<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1305 default set of specifications which are then (possibly) overriden by the
1306 specifications in the <tt>datalayout</tt> keyword. The default specifications
1307 are given in this list:</p>
1308
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1309<ul>
1310 <li><tt>E</tt> - big endian</li>
Dan Gohmanfdf2e8c2010-02-23 02:44:03 +0000[diff] [blame]1311 <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]1312 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1313 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1314 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1315 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1316 <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]1317 alignment of 64-bits</li>
1318 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1319 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1320 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1321 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1322 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1323 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1324</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1325
1326<p>When LLVM is determining the alignment for a given type, it uses the
1327 following rules:</p>
1328
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1329<ol>
1330 <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]1331 specification is used.</li>
1332
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1333 <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]1334 smallest integer type that is larger than the bitwidth of the sought type
1335 is used. If none of the specifications are larger than the bitwidth then
1336 the the largest integer type is used. For example, given the default
1337 specifications above, the i7 type will use the alignment of i8 (next
1338 largest) while both i65 and i256 will use the alignment of i64 (largest
1339 specified).</li>
1340
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1341 <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]1342 largest vector type that is smaller than the sought vector type will be
1343 used as a fall back. This happens because &lt;128 x double&gt; can be
1344 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1345</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1346
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1347</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1348
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1349<!-- ======================================================================= -->
1350<div class="doc_subsection">
1351 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1352</div>
1353
1354<div class="doc_text">
1355
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1356<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1357with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1358is undefined. Pointer values are associated with address ranges
1359according to the following rules:</p>
1360
1361<ul>
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1362 <li>A pointer value formed from a
1363 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1364 is associated with the addresses associated with the first operand
1365 of the <tt>getelementptr</tt>.</li>
1366 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1367 range of the variable's storage.</li>
1368 <li>The result value of an allocation instruction is associated with
1369 the address range of the allocated storage.</li>
1370 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1371 no address.</li>
1372 <li>A pointer value formed by an
1373 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1374 address ranges of all pointer values that contribute (directly or
1375 indirectly) to the computation of the pointer's value.</li>
1376 <li>The result value of a
1377 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1378 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1379 <li>An integer constant other than zero or a pointer value returned
1380 from a function not defined within LLVM may be associated with address
1381 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1382 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1383 allocated by mechanisms provided by LLVM.</li>
1384 </ul>
1385
1386<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1387<tt><a href="#i_load">load</a></tt> merely indicates the size and
1388alignment of the memory from which to load, as well as the
1389interpretation of the value. The first operand of a
1390<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1391and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1392
1393<p>Consequently, type-based alias analysis, aka TBAA, aka
1394<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1395LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1396additional information which specialized optimization passes may use
1397to implement type-based alias analysis.</p>
1398
1399</div>
1400
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1401<!-- ======================================================================= -->
1402<div class="doc_subsection">
1403 <a name="volatile">Volatile Memory Accesses</a>
1404</div>
1405
1406<div class="doc_text">
1407
1408<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1409href="#i_store"><tt>store</tt></a>s, and <a
1410href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1411The optimizers must not change the number of volatile operations or change their
1412order of execution relative to other volatile operations. The optimizers
1413<i>may</i> change the order of volatile operations relative to non-volatile
1414operations. This is not Java's "volatile" and has no cross-thread
1415synchronization behavior.</p>
1416
1417</div>
1418
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1419<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1420<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1421<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1422
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1423<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1424
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1425<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1426 intermediate representation. Being typed enables a number of optimizations
1427 to be performed on the intermediate representation directly, without having
1428 to do extra analyses on the side before the transformation. A strong type
1429 system makes it easier to read the generated code and enables novel analyses
1430 and transformations that are not feasible to perform on normal three address
1431 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1432
1433</div>
1434
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1435<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1436<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1437Classifications</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1438
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1439<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1440
1441<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1442
1443<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1444 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1445 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1446 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1447 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1448 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1449 </tr>
1450 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1451 <td><a href="#t_floating">floating point</a></td>
1452 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1453 </tr>
1454 <tr>
1455 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1456 <td><a href="#t_integer">integer</a>,
1457 <a href="#t_floating">floating point</a>,
1458 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1459 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1460 <a href="#t_struct">structure</a>,
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1461 <a href="#t_union">union</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1462 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1463 <a href="#t_label">label</a>,
1464 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1465 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1466 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1467 <tr>
1468 <td><a href="#t_primitive">primitive</a></td>
1469 <td><a href="#t_label">label</a>,
1470 <a href="#t_void">void</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1471 <a href="#t_floating">floating point</a>,
1472 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1473 </tr>
1474 <tr>
1475 <td><a href="#t_derived">derived</a></td>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1476 <td><a href="#t_array">array</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1477 <a href="#t_function">function</a>,
1478 <a href="#t_pointer">pointer</a>,
1479 <a href="#t_struct">structure</a>,
1480 <a href="#t_pstruct">packed structure</a>,
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1481 <a href="#t_union">union</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1482 <a href="#t_vector">vector</a>,
1483 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1484 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1485 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1486 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1487</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1488
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1489<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1490 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1491 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1492
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1493</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1494
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1495<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1496<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1497
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1498<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1499
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1500<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1501 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1502
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1503</div>
1504
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1505<!-- _______________________________________________________________________ -->
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1506<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1507
1508<div class="doc_text">
1509
1510<h5>Overview:</h5>
1511<p>The integer type is a very simple type that simply specifies an arbitrary
1512 bit width for the integer type desired. Any bit width from 1 bit to
1513 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1514
1515<h5>Syntax:</h5>
1516<pre>
1517 iN
1518</pre>
1519
1520<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1521 value.</p>
1522
1523<h5>Examples:</h5>
1524<table class="layout">
1525 <tr class="layout">
1526 <td class="left"><tt>i1</tt></td>
1527 <td class="left">a single-bit integer.</td>
1528 </tr>
1529 <tr class="layout">
1530 <td class="left"><tt>i32</tt></td>
1531 <td class="left">a 32-bit integer.</td>
1532 </tr>
1533 <tr class="layout">
1534 <td class="left"><tt>i1942652</tt></td>
1535 <td class="left">a really big integer of over 1 million bits.</td>
1536 </tr>
1537</table>
1538
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1539</div>
1540
1541<!-- _______________________________________________________________________ -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1542<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1543
1544<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1545
1546<table>
1547 <tbody>
1548 <tr><th>Type</th><th>Description</th></tr>
1549 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1550 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1551 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1552 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1553 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1554 </tbody>
1555</table>
1556
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1557</div>
1558
1559<!-- _______________________________________________________________________ -->
1560<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1561
1562<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1563
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1564<h5>Overview:</h5>
1565<p>The void type does not represent any value and has no size.</p>
1566
1567<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1568<pre>
1569 void
1570</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1571
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1572</div>
1573
1574<!-- _______________________________________________________________________ -->
1575<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1576
1577<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1578
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1579<h5>Overview:</h5>
1580<p>The label type represents code labels.</p>
1581
1582<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1583<pre>
1584 label
1585</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1586
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1587</div>
1588
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1589<!-- _______________________________________________________________________ -->
1590<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1591
1592<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1593
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1594<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1595<p>The metadata type represents embedded metadata. No derived types may be
1596 created from metadata except for <a href="#t_function">function</a>
1597 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1598
1599<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1600<pre>
1601 metadata
1602</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1603
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1604</div>
1605
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1606
1607<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1608<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1609
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1610<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1611
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1612<p>The real power in LLVM comes from the derived types in the system. This is
1613 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1614 useful types. Each of these types contain one or more element types which
1615 may be a primitive type, or another derived type. For example, it is
1616 possible to have a two dimensional array, using an array as the element type
1617 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1618
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1619
1620</div>
1621
1622<!-- _______________________________________________________________________ -->
1623<div class="doc_subsubsection"> <a name="t_aggregate">Aggregate Types</a> </div>
1624
1625<div class="doc_text">
1626
1627<p>Aggregate Types are a subset of derived types that can contain multiple
1628 member types. <a href="#t_array">Arrays</a>,
1629 <a href="#t_struct">structs</a>, <a href="#t_vector">vectors</a> and
1630 <a href="#t_union">unions</a> are aggregate types.</p>
1631
1632</div>
1633
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1634</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1635
1636<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1637<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1638
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1639<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1640
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1641<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1642<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1643 sequentially in memory. The array type requires a size (number of elements)
1644 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1645
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1646<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1647<pre>
1648 [&lt;# elements&gt; x &lt;elementtype&gt;]
1649</pre>
1650
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1651<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1652 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1653
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1654<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1655<table class="layout">
1656 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1657 <td class="left"><tt>[40 x i32]</tt></td>
1658 <td class="left">Array of 40 32-bit integer values.</td>
1659 </tr>
1660 <tr class="layout">
1661 <td class="left"><tt>[41 x i32]</tt></td>
1662 <td class="left">Array of 41 32-bit integer values.</td>
1663 </tr>
1664 <tr class="layout">
1665 <td class="left"><tt>[4 x i8]</tt></td>
1666 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1667 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1668</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1669<p>Here are some examples of multidimensional arrays:</p>
1670<table class="layout">
1671 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1672 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1673 <td class="left">3x4 array of 32-bit integer values.</td>
1674 </tr>
1675 <tr class="layout">
1676 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1677 <td class="left">12x10 array of single precision floating point values.</td>
1678 </tr>
1679 <tr class="layout">
1680 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1681 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1682 </tr>
1683</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1684
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1685<p>There is no restriction on indexing beyond the end of the array implied by
1686 a static type (though there are restrictions on indexing beyond the bounds
1687 of an allocated object in some cases). This means that single-dimension
1688 'variable sized array' addressing can be implemented in LLVM with a zero
1689 length array type. An implementation of 'pascal style arrays' in LLVM could
1690 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1691
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1692</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1693
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1694<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1695<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1696
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1697<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1698
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1699<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1700<p>The function type can be thought of as a function signature. It consists of
1701 a return type and a list of formal parameter types. The return type of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1702 function type is a scalar type, a void type, a struct type, or a union
1703 type. If the return type is a struct type then all struct elements must be
1704 of first class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1705
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1706<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1707<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1708 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1709</pre>
1710
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1711<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]1712 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1713 which indicates that the function takes a variable number of arguments.
1714 Variable argument functions can access their arguments with
1715 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1716 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1717 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1718
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1719<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1720<table class="layout">
1721 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1722 <td class="left"><tt>i32 (i32)</tt></td>
1723 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1724 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1725 </tr><tr class="layout">
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1726 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1727 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1728 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1729 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1730 returning <tt>float</tt>.
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1731 </td>
1732 </tr><tr class="layout">
1733 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1734 <td class="left">A vararg function that takes at least one
1735 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1736 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1737 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1738 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1739 </tr><tr class="layout">
1740 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1741 <td class="left">A function taking an <tt>i32</tt>, returning a
1742 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1743 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1744 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1745</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1746
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1747</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1748
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1749<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1750<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1751
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1752<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1753
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1754<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1755<p>The structure type is used to represent a collection of data members together
1756 in memory. The packing of the field types is defined to match the ABI of the
1757 underlying processor. The elements of a structure may be any type that has a
1758 size.</p>
1759
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]1760<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1761 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1762 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1763 Structures in registers are accessed using the
1764 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1765 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1766<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1767<pre>
1768 { &lt;type list&gt; }
1769</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1770
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1771<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1772<table class="layout">
1773 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1774 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1775 <td class="left">A triple of three <tt>i32</tt> values</td>
1776 </tr><tr class="layout">
1777 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1778 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1779 second element is a <a href="#t_pointer">pointer</a> to a
1780 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1781 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1782 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1783</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1784
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1785</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1786
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1787<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1788<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1789</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1790
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1791<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1792
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1793<h5>Overview:</h5>
1794<p>The packed structure type is used to represent a collection of data members
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1795 together in memory. There is no padding between fields. Further, the
1796 alignment of a packed structure is 1 byte. The elements of a packed
1797 structure may be any type that has a size.</p>
1798
1799<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1800 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1801 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1802
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1803<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1804<pre>
1805 &lt; { &lt;type list&gt; } &gt;
1806</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1807
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1808<h5>Examples:</h5>
1809<table class="layout">
1810 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1811 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1812 <td class="left">A triple of three <tt>i32</tt> values</td>
1813 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1814 <td class="left">
1815<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1816 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1817 second element is a <a href="#t_pointer">pointer</a> to a
1818 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1819 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1820 </tr>
1821</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1822
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1823</div>
1824
1825<!-- _______________________________________________________________________ -->
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1826<div class="doc_subsubsection"> <a name="t_union">Union Type</a> </div>
1827
1828<div class="doc_text">
1829
1830<h5>Overview:</h5>
1831<p>A union type describes an object with size and alignment suitable for
1832 an object of any one of a given set of types (also known as an "untagged"
1833 union). It is similar in concept and usage to a
1834 <a href="#t_struct">struct</a>, except that all members of the union
1835 have an offset of zero. The elements of a union may be any type that has a
1836 size. Unions must have at least one member - empty unions are not allowed.
1837 </p>
1838
1839<p>The size of the union as a whole will be the size of its largest member,
1840 and the alignment requirements of the union as a whole will be the largest
1841 alignment requirement of any member.</p>
1842
Dan Gohman2eddfef2010-02-25 16:51:31 +0000[diff] [blame]1843<p>Union members are accessed using '<tt><a href="#i_load">load</a></tt> and
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1844 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1845 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1846 Since all members are at offset zero, the getelementptr instruction does
1847 not affect the address, only the type of the resulting pointer.</p>
1848
1849<h5>Syntax:</h5>
1850<pre>
1851 union { &lt;type list&gt; }
1852</pre>
1853
1854<h5>Examples:</h5>
1855<table class="layout">
1856 <tr class="layout">
1857 <td class="left"><tt>union { i32, i32*, float }</tt></td>
1858 <td class="left">A union of three types: an <tt>i32</tt>, a pointer to
1859 an <tt>i32</tt>, and a <tt>float</tt>.</td>
1860 </tr><tr class="layout">
1861 <td class="left">
1862 <tt>union {&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1863 <td class="left">A union, where the first element is a <tt>float</tt> and the
1864 second element is a <a href="#t_pointer">pointer</a> to a
1865 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1866 an <tt>i32</tt>.</td>
1867 </tr>
1868</table>
1869
1870</div>
1871
1872<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1873<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1874
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1875<div class="doc_text">
1876
1877<h5>Overview:</h5>
Dan Gohmanff3ef322010-02-25 16:50:07 +0000[diff] [blame]1878<p>The pointer type is used to specify memory locations.
1879 Pointers are commonly used to reference objects in memory.</p>
1880
1881<p>Pointer types may have an optional address space attribute defining the
1882 numbered address space where the pointed-to object resides. The default
1883 address space is number zero. The semantics of non-zero address
1884 spaces are target-specific.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1885
1886<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1887 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1888
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1889<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1890<pre>
1891 &lt;type&gt; *
1892</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1893
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1894<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1895<table class="layout">
1896 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1897 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1898 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1899 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1900 </tr>
1901 <tr class="layout">
1902 <td class="left"><tt>i32 (i32 *) *</tt></td>
1903 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1904 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1905 <tt>i32</tt>.</td>
1906 </tr>
1907 <tr class="layout">
1908 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1909 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1910 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1911 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1912</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1913
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1914</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1915
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1916<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1917<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1918
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1919<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1920
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1921<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1922<p>A vector type is a simple derived type that represents a vector of elements.
1923 Vector types are used when multiple primitive data are operated in parallel
1924 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]1925 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1926 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1927
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1928<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1929<pre>
1930 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1931</pre>
1932
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1933<p>The number of elements is a constant integer value; elementtype may be any
1934 integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1935
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1936<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1937<table class="layout">
1938 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1939 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1940 <td class="left">Vector of 4 32-bit integer values.</td>
1941 </tr>
1942 <tr class="layout">
1943 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1944 <td class="left">Vector of 8 32-bit floating-point values.</td>
1945 </tr>
1946 <tr class="layout">
1947 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1948 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1949 </tr>
1950</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1951
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1952</div>
1953
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1954<!-- _______________________________________________________________________ -->
1955<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1956<div class="doc_text">
1957
1958<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1959<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1960 corresponds (for example) to the C notion of a forward declared structure
1961 type. In LLVM, opaque types can eventually be resolved to any type (not just
1962 a structure type).</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1963
1964<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1965<pre>
1966 opaque
1967</pre>
1968
1969<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1970<table class="layout">
1971 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1972 <td class="left"><tt>opaque</tt></td>
1973 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1974 </tr>
1975</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1976
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1977</div>
1978
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1979<!-- ======================================================================= -->
1980<div class="doc_subsection">
1981 <a name="t_uprefs">Type Up-references</a>
1982</div>
1983
1984<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1985
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1986<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1987<p>An "up reference" allows you to refer to a lexically enclosing type without
1988 requiring it to have a name. For instance, a structure declaration may
1989 contain a pointer to any of the types it is lexically a member of. Example
1990 of up references (with their equivalent as named type declarations)
1991 include:</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1992
1993<pre>
Chris Lattner3060f5b2009-02-09 10:00:56 +0000[diff] [blame]1994 { \2 * } %x = type { %x* }
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1995 { \2 }* %y = type { %y }*
1996 \1* %z = type %z*
1997</pre>
1998
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1999<p>An up reference is needed by the asmprinter for printing out cyclic types
2000 when there is no declared name for a type in the cycle. Because the
2001 asmprinter does not want to print out an infinite type string, it needs a
2002 syntax to handle recursive types that have no names (all names are optional
2003 in llvm IR).</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2004
2005<h5>Syntax:</h5>
2006<pre>
2007 \&lt;level&gt;
2008</pre>
2009
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2010<p>The level is the count of the lexical type that is being referred to.</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2011
2012<h5>Examples:</h5>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2013<table class="layout">
2014 <tr class="layout">
2015 <td class="left"><tt>\1*</tt></td>
2016 <td class="left">Self-referential pointer.</td>
2017 </tr>
2018 <tr class="layout">
2019 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
2020 <td class="left">Recursive structure where the upref refers to the out-most
2021 structure.</td>
2022 </tr>
2023</table>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2024
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2025</div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2026
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2027<!-- *********************************************************************** -->
2028<div class="doc_section"> <a name="constants">Constants</a> </div>
2029<!-- *********************************************************************** -->
2030
2031<div class="doc_text">
2032
2033<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2034 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2035
2036</div>
2037
2038<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]2039<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2040
2041<div class="doc_text">
2042
2043<dl>
2044 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2045 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]2046 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2047
2048 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2049 <dd>Standard integers (such as '4') are constants of
2050 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2051 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2052
2053 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2054 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2055 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2056 notation (see below). The assembler requires the exact decimal value of a
2057 floating-point constant. For example, the assembler accepts 1.25 but
2058 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2059 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2060
2061 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2062 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2063 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2064</dl>
2065
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2066<p>The one non-intuitive notation for constants is the hexadecimal form of
2067 floating point constants. For example, the form '<tt>double
2068 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2069 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2070 constants are required (and the only time that they are generated by the
2071 disassembler) is when a floating point constant must be emitted but it cannot
2072 be represented as a decimal floating point number in a reasonable number of
2073 digits. For example, NaN's, infinities, and other special values are
2074 represented in their IEEE hexadecimal format so that assembly and disassembly
2075 do not cause any bits to change in the constants.</p>
2076
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]2077<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2078 represented using the 16-digit form shown above (which matches the IEEE754
2079 representation for double); float values must, however, be exactly
2080 representable as IEE754 single precision. Hexadecimal format is always used
2081 for long double, and there are three forms of long double. The 80-bit format
2082 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2083 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2084 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2085 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2086 currently supported target uses this format. Long doubles will only work if
2087 they match the long double format on your target. All hexadecimal formats
2088 are big-endian (sign bit at the left).</p>
2089
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2090</div>
2091
2092<!-- ======================================================================= -->
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2093<div class="doc_subsection">
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2094<a name="aggregateconstants"></a> <!-- old anchor -->
2095<a name="complexconstants">Complex Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2096</div>
2097
2098<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2099
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2100<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2101 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2102
2103<dl>
2104 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2105 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2106 type definitions (a comma separated list of elements, surrounded by braces
2107 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2108 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2109 Structure constants must have <a href="#t_struct">structure type</a>, and
2110 the number and types of elements must match those specified by the
2111 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2112
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2113 <dt><b>Union constants</b></dt>
2114 <dd>Union constants are represented with notation similar to a structure with
2115 a single element - that is, a single typed element surrounded
2116 by braces (<tt>{}</tt>)). For example: "<tt>{ i32 4 }</tt>". The
2117 <a href="#t_union">union type</a> can be initialized with a single-element
2118 struct as long as the type of the struct element matches the type of
2119 one of the union members.</dd>
2120
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2121 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2122 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2123 definitions (a comma separated list of elements, surrounded by square
2124 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2125 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2126 the number and types of elements must match those specified by the
2127 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2128
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2129 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2130 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2131 definitions (a comma separated list of elements, surrounded by
2132 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2133 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2134 have <a href="#t_vector">vector type</a>, and the number and types of
2135 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2136
2137 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2138 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2139 value to zero of <em>any</em> type, including scalar and
2140 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2141 This is often used to avoid having to print large zero initializers
2142 (e.g. for large arrays) and is always exactly equivalent to using explicit
2143 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2144
2145 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2146 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2147 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2148 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2149 be interpreted as part of the instruction stream, metadata is a place to
2150 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2151</dl>
2152
2153</div>
2154
2155<!-- ======================================================================= -->
2156<div class="doc_subsection">
2157 <a name="globalconstants">Global Variable and Function Addresses</a>
2158</div>
2159
2160<div class="doc_text">
2161
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2162<p>The addresses of <a href="#globalvars">global variables</a>
2163 and <a href="#functionstructure">functions</a> are always implicitly valid
2164 (link-time) constants. These constants are explicitly referenced when
2165 the <a href="#identifiers">identifier for the global</a> is used and always
2166 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2167 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2168
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2169<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2170<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2171@X = global i32 17
2172@Y = global i32 42
2173@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2174</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2175</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2176
2177</div>
2178
2179<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]2180<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2181<div class="doc_text">
2182
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2183<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]2184 indicates that the user of the value may receive an unspecified bit-pattern.
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2185 Undefined values may be of any type (other than label or void) and be used
2186 anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2187
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2188<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2189 program is well defined no matter what value is used. This gives the
2190 compiler more freedom to optimize. Here are some examples of (potentially
2191 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2192
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2193
2194<div class="doc_code">
2195<pre>
2196 %A = add %X, undef
2197 %B = sub %X, undef
2198 %C = xor %X, undef
2199Safe:
2200 %A = undef
2201 %B = undef
2202 %C = undef
2203</pre>
2204</div>
2205
2206<p>This is safe because all of the output bits are affected by the undef bits.
2207Any output bit can have a zero or one depending on the input bits.</p>
2208
2209<div class="doc_code">
2210<pre>
2211 %A = or %X, undef
2212 %B = and %X, undef
2213Safe:
2214 %A = -1
2215 %B = 0
2216Unsafe:
2217 %A = undef
2218 %B = undef
2219</pre>
2220</div>
2221
2222<p>These logical operations have bits that are not always affected by the input.
2223For example, if "%X" has a zero bit, then the output of the 'and' operation will
2224always be a zero, no matter what the corresponding bit from the undef is. As
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2225such, it is unsafe to optimize or assume that the result of the and is undef.
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2226However, it is safe to assume that all bits of the undef could be 0, and
2227optimize the and to 0. Likewise, it is safe to assume that all the bits of
2228the undef operand to the or could be set, allowing the or to be folded to
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2229-1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2230
2231<div class="doc_code">
2232<pre>
2233 %A = select undef, %X, %Y
2234 %B = select undef, 42, %Y
2235 %C = select %X, %Y, undef
2236Safe:
2237 %A = %X (or %Y)
2238 %B = 42 (or %Y)
2239 %C = %Y
2240Unsafe:
2241 %A = undef
2242 %B = undef
2243 %C = undef
2244</pre>
2245</div>
2246
2247<p>This set of examples show that undefined select (and conditional branch)
2248conditions can go "either way" but they have to come from one of the two
2249operands. In the %A example, if %X and %Y were both known to have a clear low
2250bit, then %A would have to have a cleared low bit. However, in the %C example,
2251the optimizer is allowed to assume that the undef operand could be the same as
2252%Y, allowing the whole select to be eliminated.</p>
2253
2254
2255<div class="doc_code">
2256<pre>
2257 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2258
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2259 %B = undef
2260 %C = xor %B, %B
2261
2262 %D = undef
2263 %E = icmp lt %D, 4
2264 %F = icmp gte %D, 4
2265
2266Safe:
2267 %A = undef
2268 %B = undef
2269 %C = undef
2270 %D = undef
2271 %E = undef
2272 %F = undef
2273</pre>
2274</div>
2275
2276<p>This example points out that two undef operands are not necessarily the same.
2277This can be surprising to people (and also matches C semantics) where they
2278assume that "X^X" is always zero, even if X is undef. This isn't true for a
2279number of reasons, but the short answer is that an undef "variable" can
2280arbitrarily change its value over its "live range". This is true because the
2281"variable" doesn't actually <em>have a live range</em>. Instead, the value is
2282logically read from arbitrary registers that happen to be around when needed,
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]2283so the value is not necessarily consistent over time. In fact, %A and %C need
Chris Lattner349eb412009-09-08 15:13:16 +0000[diff] [blame]2284to have the same semantics or the core LLVM "replace all uses with" concept
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2285would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2286
2287<div class="doc_code">
2288<pre>
2289 %A = fdiv undef, %X
2290 %B = fdiv %X, undef
2291Safe:
2292 %A = undef
2293b: unreachable
2294</pre>
2295</div>
2296
2297<p>These examples show the crucial difference between an <em>undefined
2298value</em> and <em>undefined behavior</em>. An undefined value (like undef) is
2299allowed to have an arbitrary bit-pattern. This means that the %A operation
2300can be constant folded to undef because the undef could be an SNaN, and fdiv is
2301not (currently) defined on SNaN's. However, in the second example, we can make
2302a more aggressive assumption: because the undef is allowed to be an arbitrary
2303value, we are allowed to assume that it could be zero. Since a divide by zero
Chris Lattner8e371aa2009-09-08 19:45:34 +0000[diff] [blame]2304has <em>undefined behavior</em>, we are allowed to assume that the operation
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2305does not execute at all. This allows us to delete the divide and all code after
2306it: since the undefined operation "can't happen", the optimizer can assume that
2307it occurs in dead code.
2308</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2309
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2310<div class="doc_code">
2311<pre>
2312a: store undef -> %X
2313b: store %X -> undef
2314Safe:
2315a: &lt;deleted&gt;
2316b: unreachable
2317</pre>
2318</div>
2319
2320<p>These examples reiterate the fdiv example: a store "of" an undefined value
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2321can be assumed to not have any effect: we can assume that the value is
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2322overwritten with bits that happen to match what was already there. However, a
2323store "to" an undefined location could clobber arbitrary memory, therefore, it
2324has undefined behavior.</p>
2325
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2326</div>
2327
2328<!-- ======================================================================= -->
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2329<div class="doc_subsection"><a name="trapvalues">Trap Values</a></div>
2330<div class="doc_text">
2331
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2332<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2333 instead of representing an unspecified bit pattern, they represent the
2334 fact that an instruction or constant expression which cannot evoke side
2335 effects has nevertheless detected a condition which results in undefined
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2336 behavior.</p>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2337
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2338<p>Any value other than a non-intrinsic call, invoke, or phi with a trap
2339 operand has trap as its result value. Any instruction with
2340 a trap operand which may have side effects emits those side effects as
2341 if it had an undef operand instead. If the side effects are externally
2342 visible, the behavior is undefined.</p>
2343
2344<p>Trap values may be stored to memory; a load from memory including any
2345 part of a trap value results in a (full) trap value.</p>
2346
2347<p>For example:</p>
2348
2349<!-- FIXME: In the case of multiple threads, this only applies to loads from
2350 the same thread as the store, or loads which are sequenced after the
2351 store by synchronization. -->
2352
2353<div class="doc_code">
2354<pre>
2355%trap = sub nuw i32 0, 1 ; Results in a trap value.
2356%still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2357%trap_yet_again = getelementptr i32* @h, i32 %still_trap
2358store i32 0, i32* %trap_yet_again ; undefined behavior
2359
2360volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2361%trap2 = load i32* @g ; Returns a trap value, not just undef.
2362%narrowaddr = bitcast i32* @g to i16*
2363%wideaddr = bitcast i32* @g to i64*
2364%trap3 = load 16* %narrowaddr ; Returns a trap value
2365%trap4 = load i64* %widaddr ; Returns a trap value, not partial trap.
2366</pre>
2367</div>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2368
Dan Gohmanc30f6e12010-04-26 20:54:53 +0000[diff] [blame]2369<p>If a <a href="#i_br"><tt>br</tt></a> or
2370 <a href="#i_switch"><tt>switch</tt></a> instruction has a trap value
2371 operand, all non-phi non-void instructions which control-depend on it
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2372 have trap as their result value. A <a href="#i_phi"><tt>phi</tt></a>
2373 node with an incoming value associated with a control edge which is
2374 control-dependent on it has trap as its result value when control is
2375 transferred from that block. If any instruction which control-depends
2376 on the <tt>br</tt> or <tt>switch</tt> invokes externally visible side
2377 effects, the behavior of the program is undefined. For example:</p>
Dan Gohmanc30f6e12010-04-26 20:54:53 +0000[diff] [blame]2378
2379<!-- FIXME: What about exceptions thrown from control-dependent instrs? -->
2380
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2381<div class="doc_code">
2382<pre>
2383entry:
2384 %trap = sub nuw i32 0, 1 ; Results in a trap value.
2385 %cmp = icmp i32 slt %trap, 0 ; Still trap.
2386 %br i1 %cmp, %true, %end ; Branch to either destination.
2387
2388true:
2389 volatile store i32 0, i32* @g ; Externally visible side effects
2390 ; control-dependent on %cmp.
2391 ; Undefined behavior.
2392 br label %end
2393
2394end:
2395 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2396 ; Both edges into this PHI are
2397 ; control-dependent on %cmp, so this
2398 ; results in a trap value.
2399
2400 volatile store i32 0, i32* @g ; %end is control-equivalent to %entry
2401 ; so this is defined (ignoring earlier
2402 ; undefined behavior in this example).
2403
2404</pre>
2405</div>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2406
2407<p>There is currently no way of representing a trap constant in the IR; they
2408 only exist when produced by certain instructions, such as an
2409 <a href="#i_add"><tt>add</tt></a> with the <tt>nsw</tt> flag
2410 set, when overflow occurs.</p>
2411
2412</div>
2413
2414<!-- ======================================================================= -->
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]2415<div class="doc_subsection"><a name="blockaddress">Addresses of Basic
2416 Blocks</a></div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2417<div class="doc_text">
2418
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2419<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2420
2421<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2422 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2423 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2424
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2425<p>This value only has defined behavior when used as an operand to the
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2426 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction or for comparisons
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2427 against null. Pointer equality tests between labels addresses is undefined
2428 behavior - though, again, comparison against null is ok, and no label is
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]2429 equal to the null pointer. This may also be passed around as an opaque
2430 pointer sized value as long as the bits are not inspected. This allows
Chris Lattner3fd77ce2009-10-27 21:44:20 +0000[diff] [blame]2431 <tt>ptrtoint</tt> and arithmetic to be performed on these values so long as
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2432 the original value is reconstituted before the <tt>indirectbr</tt>.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2433
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]2434<p>Finally, some targets may provide defined semantics when
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2435 using the value as the operand to an inline assembly, but that is target
2436 specific.
2437 </p>
2438
2439</div>
2440
2441
2442<!-- ======================================================================= -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2443<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2444</div>
2445
2446<div class="doc_text">
2447
2448<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2449 to be used as constants. Constant expressions may be of
2450 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2451 operation that does not have side effects (e.g. load and call are not
2452 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2453
2454<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2455 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2456 <dd>Truncate a constant to another type. The bit size of CST must be larger
2457 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2458
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2459 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2460 <dd>Zero extend a constant to another type. The bit size of CST must be
2461 smaller or equal to the bit size of TYPE. Both types must be
2462 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2463
2464 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2465 <dd>Sign extend a constant to another type. The bit size of CST must be
2466 smaller or equal to the bit size of TYPE. Both types must be
2467 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2468
2469 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2470 <dd>Truncate a floating point constant to another floating point type. The
2471 size of CST must be larger than the size of TYPE. Both types must be
2472 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2473
2474 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2475 <dd>Floating point extend a constant to another type. The size of CST must be
2476 smaller or equal to the size of TYPE. Both types must be floating
2477 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2478
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]2479 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2480 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2481 constant. TYPE must be a scalar or vector integer type. CST must be of
2482 scalar or vector floating point type. Both CST and TYPE must be scalars,
2483 or vectors of the same number of elements. If the value won't fit in the
2484 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2485
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2486 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2487 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2488 constant. TYPE must be a scalar or vector integer type. CST must be of
2489 scalar or vector floating point type. Both CST and TYPE must be scalars,
2490 or vectors of the same number of elements. If the value won't fit in the
2491 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2492
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2493 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2494 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2495 constant. TYPE must be a scalar or vector floating point type. CST must be
2496 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2497 vectors of the same number of elements. If the value won't fit in the
2498 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2499
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2500 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2501 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2502 constant. TYPE must be a scalar or vector floating point type. CST must be
2503 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2504 vectors of the same number of elements. If the value won't fit in the
2505 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2506
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2507 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2508 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2509 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2510 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2511 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2512
2513 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2514 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2515 type. CST must be of integer type. The CST value is zero extended,
2516 truncated, or unchanged to make it fit in a pointer size. This one is
2517 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2518
2519 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2520 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2521 are the same as those for the <a href="#i_bitcast">bitcast
2522 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2523
2524 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]2525 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2526 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2527 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2528 instruction, the index list may have zero or more indexes, which are
2529 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2530
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2531 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2532 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2533
2534 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2535 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2536
2537 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2538 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2539
2540 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2541 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2542 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2543
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]2544 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2545 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2546 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2547
2548 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2549 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2550 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2551
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2552 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2553 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2554 be any of the <a href="#binaryops">binary</a>
2555 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2556 on operands are the same as those for the corresponding instruction
2557 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2558</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2559
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2560</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2561
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2562<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2563<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2564<!-- *********************************************************************** -->
2565
2566<!-- ======================================================================= -->
2567<div class="doc_subsection">
2568<a name="inlineasm">Inline Assembler Expressions</a>
2569</div>
2570
2571<div class="doc_text">
2572
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2573<p>LLVM supports inline assembler expressions (as opposed
2574 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2575 a special value. This value represents the inline assembler as a string
2576 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2577 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2578 expression has side effects, and a flag indicating whether the function
2579 containing the asm needs to align its stack conservatively. An example
2580 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2581
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2582<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2583<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2584i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2585</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2586</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2587
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2588<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2589 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2590 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2591
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2592<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2593<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2594%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]2595</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2596</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2597
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2598<p>Inline asms with side effects not visible in the constraint list must be
2599 marked as having side effects. This is done through the use of the
2600 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2601
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2602<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2603<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2604call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2605</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2606</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2607
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2608<p>In some cases inline asms will contain code that will not work unless the
2609 stack is aligned in some way, such as calls or SSE instructions on x86,
2610 yet will not contain code that does that alignment within the asm.
2611 The compiler should make conservative assumptions about what the asm might
2612 contain and should generate its usual stack alignment code in the prologue
2613 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2614
2615<div class="doc_code">
2616<pre>
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2617call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2618</pre>
2619</div>
2620
2621<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2622 first.</p>
2623
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2624<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2625 documented here. Constraints on what can be done (e.g. duplication, moving,
2626 etc need to be documented). This is probably best done by reference to
2627 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2628</div>
2629
2630<div class="doc_subsubsection">
2631<a name="inlineasm_md">Inline Asm Metadata</a>
2632</div>
2633
2634<div class="doc_text">
2635
2636<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
2637 attached to it that contains a constant integer. If present, the code
2638 generator will use the integer as the location cookie value when report
2639 errors through the LLVMContext error reporting mechanisms. This allows a
2640 front-end to corrolate backend errors that occur with inline asm back to the
2641 source code that produced it. For example:</p>
2642
2643<div class="doc_code">
2644<pre>
2645call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2646...
2647!42 = !{ i32 1234567 }
2648</pre>
2649</div>
2650
2651<p>It is up to the front-end to make sense of the magic numbers it places in the
2652 IR.</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2653
2654</div>
2655
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2656<!-- ======================================================================= -->
2657<div class="doc_subsection"><a name="metadata">Metadata Nodes and Metadata
2658 Strings</a>
2659</div>
2660
2661<div class="doc_text">
2662
2663<p>LLVM IR allows metadata to be attached to instructions in the program that
2664 can convey extra information about the code to the optimizers and code
2665 generator. One example application of metadata is source-level debug
2666 information. There are two metadata primitives: strings and nodes. All
2667 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2668 preceding exclamation point ('<tt>!</tt>').</p>
2669
2670<p>A metadata string is a string surrounded by double quotes. It can contain
2671 any character by escaping non-printable characters with "\xx" where "xx" is
2672 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2673
2674<p>Metadata nodes are represented with notation similar to structure constants
2675 (a comma separated list of elements, surrounded by braces and preceded by an
2676 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2677 10}</tt>". Metadata nodes can have any values as their operand.</p>
2678
2679<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2680 metadata nodes, which can be looked up in the module symbol table. For
2681 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2682
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2683<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
2684 function is using two metadata arguments.
2685
2686 <div class="doc_code">
2687 <pre>
2688 call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2689 </pre>
2690 </div></p>
2691
2692<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
2693 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.
2694
2695 <div class="doc_code">
2696 <pre>
2697 %indvar.next = add i64 %indvar, 1, !dbg !21
2698 </pre>
2699 </div></p>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2700</div>
2701
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2702
2703<!-- *********************************************************************** -->
2704<div class="doc_section">
2705 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2706</div>
2707<!-- *********************************************************************** -->
2708
2709<p>LLVM has a number of "magic" global variables that contain data that affect
2710code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2711of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2712section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2713by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2714
2715<!-- ======================================================================= -->
2716<div class="doc_subsection">
2717<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2718</div>
2719
2720<div class="doc_text">
2721
2722<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2723href="#linkage_appending">appending linkage</a>. This array contains a list of
2724pointers to global variables and functions which may optionally have a pointer
2725cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2726
2727<pre>
2728 @X = global i8 4
2729 @Y = global i32 123
2730
2731 @llvm.used = appending global [2 x i8*] [
2732 i8* @X,
2733 i8* bitcast (i32* @Y to i8*)
2734 ], section "llvm.metadata"
2735</pre>
2736
2737<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2738compiler, assembler, and linker are required to treat the symbol as if there is
2739a reference to the global that it cannot see. For example, if a variable has
2740internal linkage and no references other than that from the <tt>@llvm.used</tt>
2741list, it cannot be deleted. This is commonly used to represent references from
2742inline asms and other things the compiler cannot "see", and corresponds to
2743"attribute((used))" in GNU C.</p>
2744
2745<p>On some targets, the code generator must emit a directive to the assembler or
2746object file to prevent the assembler and linker from molesting the symbol.</p>
2747
2748</div>
2749
2750<!-- ======================================================================= -->
2751<div class="doc_subsection">
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2752<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2753</div>
2754
2755<div class="doc_text">
2756
2757<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2758<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2759touching the symbol. On targets that support it, this allows an intelligent
2760linker to optimize references to the symbol without being impeded as it would be
2761by <tt>@llvm.used</tt>.</p>
2762
2763<p>This is a rare construct that should only be used in rare circumstances, and
2764should not be exposed to source languages.</p>
2765
2766</div>
2767
2768<!-- ======================================================================= -->
2769<div class="doc_subsection">
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2770<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2771</div>
2772
2773<div class="doc_text">
2774
2775<p>TODO: Describe this.</p>
2776
2777</div>
2778
2779<!-- ======================================================================= -->
2780<div class="doc_subsection">
2781<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2782</div>
2783
2784<div class="doc_text">
2785
2786<p>TODO: Describe this.</p>
2787
2788</div>
2789
2790
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2791<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2792<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2793<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2794
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2795<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2796
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2797<p>The LLVM instruction set consists of several different classifications of
2798 instructions: <a href="#terminators">terminator
2799 instructions</a>, <a href="#binaryops">binary instructions</a>,
2800 <a href="#bitwiseops">bitwise binary instructions</a>,
2801 <a href="#memoryops">memory instructions</a>, and
2802 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2803
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2804</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2805
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2806<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2807<div class="doc_subsection"> <a name="terminators">Terminator
2808Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2809
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2810<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2811
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2812<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2813 in a program ends with a "Terminator" instruction, which indicates which
2814 block should be executed after the current block is finished. These
2815 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2816 control flow, not values (the one exception being the
2817 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2818
Duncan Sands83821c82010-04-15 20:35:54 +0000[diff] [blame]2819<p>There are seven different terminator instructions: the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2820 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2821 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2822 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling21c346e2009-11-02 00:25:26 +0000[diff] [blame]2823 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2824 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2825 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2826 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2827
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2828</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2829
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2830<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2831<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2832Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2833
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2834<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2835
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2836<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2837<pre>
2838 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]2839 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2840</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2841
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2842<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2843<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2844 a value) from a function back to the caller.</p>
2845
2846<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2847 value and then causes control flow, and one that just causes control flow to
2848 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2849
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2850<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2851<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2852 return value. The type of the return value must be a
2853 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2854
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2855<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2856 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2857 value or a return value with a type that does not match its type, or if it
2858 has a void return type and contains a '<tt>ret</tt>' instruction with a
2859 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2860
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2861<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2862<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2863 the calling function's context. If the caller is a
2864 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2865 instruction after the call. If the caller was an
2866 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2867 the beginning of the "normal" destination block. If the instruction returns
2868 a value, that value shall set the call or invoke instruction's return
2869 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2870
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2871<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2872<pre>
2873 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2874 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]2875 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]2876</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2877
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2878</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2879<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2880<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2881
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2882<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2883
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2884<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2885<pre>
2886 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]2887</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2888
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2889<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2890<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2891 different basic block in the current function. There are two forms of this
2892 instruction, corresponding to a conditional branch and an unconditional
2893 branch.</p>
2894
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2895<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2896<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2897 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2898 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2899 target.</p>
2900
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2901<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2902<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2903 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2904 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2905 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2906
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2907<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2908<pre>
2909Test:
2910 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2911 br i1 %cond, label %IfEqual, label %IfUnequal
2912IfEqual:
2913 <a href="#i_ret">ret</a> i32 1
2914IfUnequal:
2915 <a href="#i_ret">ret</a> i32 0
2916</pre>
2917
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2918</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2919
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2920<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2921<div class="doc_subsubsection">
2922 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2923</div>
2924
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2925<div class="doc_text">
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2926
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2927<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2928<pre>
2929 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2930</pre>
2931
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2932<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2933<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]2934 several different places. It is a generalization of the '<tt>br</tt>'
2935 instruction, allowing a branch to occur to one of many possible
2936 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2937
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2938<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2939<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2940 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2941 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2942 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2943
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2944<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2945<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2946 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2947 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]2948 transferred to the corresponding destination; otherwise, control flow is
2949 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2950
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2951<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2952<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2953 <tt>switch</tt> instruction, this instruction may be code generated in
2954 different ways. For example, it could be generated as a series of chained
2955 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2956
2957<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2958<pre>
2959 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2960 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2961 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2962
2963 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2964 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2965
2966 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2967 switch i32 %val, label %otherwise [ i32 0, label %onzero
2968 i32 1, label %onone
2969 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2970</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2971
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2972</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2973
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2974
2975<!-- _______________________________________________________________________ -->
2976<div class="doc_subsubsection">
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2977 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2978</div>
2979
2980<div class="doc_text">
2981
2982<h5>Syntax:</h5>
2983<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2984 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]2985</pre>
2986
2987<h5>Overview:</h5>
2988
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2989<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2990 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2991 "<tt>address</tt>". Address must be derived from a <a
2992 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2993
2994<h5>Arguments:</h5>
2995
2996<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
2997 rest of the arguments indicate the full set of possible destinations that the
2998 address may point to. Blocks are allowed to occur multiple times in the
2999 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3000
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3001<p>This destination list is required so that dataflow analysis has an accurate
3002 understanding of the CFG.</p>
3003
3004<h5>Semantics:</h5>
3005
3006<p>Control transfers to the block specified in the address argument. All
3007 possible destination blocks must be listed in the label list, otherwise this
3008 instruction has undefined behavior. This implies that jumps to labels
3009 defined in other functions have undefined behavior as well.</p>
3010
3011<h5>Implementation:</h5>
3012
3013<p>This is typically implemented with a jump through a register.</p>
3014
3015<h5>Example:</h5>
3016<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3017 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3018</pre>
3019
3020</div>
3021
3022
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3023<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3024<div class="doc_subsubsection">
3025 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
3026</div>
3027
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3028<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3029
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3030<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3031<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3032 &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]3033 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3034</pre>
3035
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3036<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3037<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3038 function, with the possibility of control flow transfer to either the
3039 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3040 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3041 control flow will return to the "normal" label. If the callee (or any
3042 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3043 instruction, control is interrupted and continued at the dynamically nearest
3044 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3045
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3046<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3047<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3048
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3049<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3050 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3051 convention</a> the call should use. If none is specified, the call
3052 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3053
3054 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3055 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3056 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3057
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3058 <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]3059 function value being invoked. In most cases, this is a direct function
3060 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3061 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3062
3063 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3064 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3065
3066 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]3067 signature argument types and parameter attributes. All arguments must be
3068 of <a href="#t_firstclass">first class</a> type. If the function
3069 signature indicates the function accepts a variable number of arguments,
3070 the extra arguments can be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3071
3072 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3073 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3074
3075 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3076 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3077
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3078 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3079 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3080 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3081</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3082
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3083<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3084<p>This instruction is designed to operate as a standard
3085 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3086 primary difference is that it establishes an association with a label, which
3087 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3088
3089<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3090 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3091 exception. Additionally, this is important for implementation of
3092 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3093
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3094<p>For the purposes of the SSA form, the definition of the value returned by the
3095 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3096 block to the "normal" label. If the callee unwinds then no return value is
3097 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]3098
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3099<p>Note that the code generator does not yet completely support unwind, and
3100that the invoke/unwind semantics are likely to change in future versions.</p>
3101
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3102<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3103<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3104 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3105 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3106 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3107 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3108</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3109
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3110</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3111
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3112<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3113
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3114<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
3115Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3116
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3117<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3118
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3119<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3120<pre>
3121 unwind
3122</pre>
3123
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3124<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3125<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3126 at the first callee in the dynamic call stack which used
3127 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3128 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3129
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3130<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3131<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3132 immediately halt. The dynamic call stack is then searched for the
3133 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3134 Once found, execution continues at the "exceptional" destination block
3135 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3136 instruction in the dynamic call chain, undefined behavior results.</p>
3137
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3138<p>Note that the code generator does not yet completely support unwind, and
3139that the invoke/unwind semantics are likely to change in future versions.</p>
3140
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3141</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3142
3143<!-- _______________________________________________________________________ -->
3144
3145<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
3146Instruction</a> </div>
3147
3148<div class="doc_text">
3149
3150<h5>Syntax:</h5>
3151<pre>
3152 unreachable
3153</pre>
3154
3155<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3156<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3157 instruction is used to inform the optimizer that a particular portion of the
3158 code is not reachable. This can be used to indicate that the code after a
3159 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3160
3161<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3162<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3163
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3164</div>
3165
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3166<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3167<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3168
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3169<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3170
3171<p>Binary operators are used to do most of the computation in a program. They
3172 require two operands of the same type, execute an operation on them, and
3173 produce a single value. The operands might represent multiple data, as is
3174 the case with the <a href="#t_vector">vector</a> data type. The result value
3175 has the same type as its operands.</p>
3176
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3177<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3178
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3179</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3180
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3181<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3182<div class="doc_subsubsection">
3183 <a name="i_add">'<tt>add</tt>' Instruction</a>
3184</div>
3185
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3186<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3187
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3188<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3189<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3190 &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]3191 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3192 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3193 &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]3194</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3195
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3196<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3197<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3198
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3199<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3200<p>The two arguments to the '<tt>add</tt>' instruction must
3201 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3202 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3203
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3204<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3205<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3206
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3207<p>If the sum has unsigned overflow, the result returned is the mathematical
3208 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]3209
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3210<p>Because LLVM integers use a two's complement representation, this instruction
3211 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3212
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3213<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3214 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3215 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3216 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3217 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3218
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3219<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3220<pre>
3221 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3222</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3223
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3224</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3225
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3226<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3227<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3228 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
3229</div>
3230
3231<div class="doc_text">
3232
3233<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3234<pre>
3235 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3236</pre>
3237
3238<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3239<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3240
3241<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3242<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3243 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3244 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3245
3246<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3247<p>The value produced is the floating point sum of the two operands.</p>
3248
3249<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3250<pre>
3251 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3252</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3253
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3254</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3255
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3256<!-- _______________________________________________________________________ -->
3257<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3258 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
3259</div>
3260
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3261<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3262
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3263<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3264<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3265 &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]3266 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3267 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3268 &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]3269</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3270
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3271<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3272<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3273 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3274
3275<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3276 '<tt>neg</tt>' instruction present in most other intermediate
3277 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3278
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3279<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3280<p>The two arguments to the '<tt>sub</tt>' instruction must
3281 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3282 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3283
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3284<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3285<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3286
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3287<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3288 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3289 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3290
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3291<p>Because LLVM integers use a two's complement representation, this instruction
3292 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3293
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3294<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3295 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3296 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3297 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3298 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3299
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3300<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3301<pre>
3302 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3303 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3304</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3305
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3306</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3307
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3308<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3309<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3310 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
3311</div>
3312
3313<div class="doc_text">
3314
3315<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3316<pre>
3317 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3318</pre>
3319
3320<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3321<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3322 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3323
3324<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3325 '<tt>fneg</tt>' instruction present in most other intermediate
3326 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3327
3328<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3329<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3330 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3331 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3332
3333<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3334<p>The value produced is the floating point difference of the two operands.</p>
3335
3336<h5>Example:</h5>
3337<pre>
3338 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3339 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3340</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3341
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3342</div>
3343
3344<!-- _______________________________________________________________________ -->
3345<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3346 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
3347</div>
3348
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3349<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3350
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3351<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3352<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3353 &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]3354 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3355 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3356 &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]3357</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3358
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3359<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3360<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3361
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3362<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3363<p>The two arguments to the '<tt>mul</tt>' instruction must
3364 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3365 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3366
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3367<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3368<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3369
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3370<p>If the result of the multiplication has unsigned overflow, the result
3371 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3372 width of the result.</p>
3373
3374<p>Because LLVM integers use a two's complement representation, and the result
3375 is the same width as the operands, this instruction returns the correct
3376 result for both signed and unsigned integers. If a full product
3377 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3378 be sign-extended or zero-extended as appropriate to the width of the full
3379 product.</p>
3380
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3381<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3382 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3383 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3384 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3385 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3386
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3387<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3388<pre>
3389 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3390</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3391
Misha Brukman9d0919f2003-11-08 01:05:38 +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<!-- _______________________________________________________________________ -->
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3395<div class="doc_subsubsection">
3396 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
3397</div>
3398
3399<div class="doc_text">
3400
3401<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3402<pre>
3403 &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]3404</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3405
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3406<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3407<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3408
3409<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3410<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3411 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3412 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3413
3414<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3415<p>The value produced is the floating point product of the two operands.</p>
3416
3417<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3418<pre>
3419 &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]3420</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3421
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3422</div>
3423
3424<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3425<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
3426</a></div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3427
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3428<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3429
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3430<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3431<pre>
3432 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3433</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3434
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3435<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3436<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3437
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3438<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3439<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3440 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3441 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3442
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3443<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3444<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3445
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3446<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3447 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3448
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3449<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3450
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3451<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3452<pre>
3453 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3454</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3455
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3456</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3457
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3458<!-- _______________________________________________________________________ -->
3459<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
3460</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3461
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3462<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3463
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3464<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3465<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3466 &lt;result&gt; = 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]3467 &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]3468</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3469
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3470<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3471<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3472
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3473<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3474<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3475 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3476 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3477
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3478<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3479<p>The value produced is the signed integer quotient of the two operands rounded
3480 towards zero.</p>
3481
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3482<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3483 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3484
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3485<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3486 undefined behavior; this is a rare case, but can occur, for example, by doing
3487 a 32-bit division of -2147483648 by -1.</p>
3488
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3489<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]3490 <tt>sdiv</tt> is a <a href="#trapvalues">trap value</a> if the result would
3491 be rounded or if overflow would occur.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3492
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3493<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3494<pre>
3495 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3496</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3497
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3498</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3499
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3500<!-- _______________________________________________________________________ -->
3501<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3502Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3503
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3504<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3505
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3506<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3507<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3508 &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]3509</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3510
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3511<h5>Overview:</h5>
3512<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3513
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3514<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3515<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3516 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3517 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3518
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3519<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3520<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3521
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3522<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3523<pre>
3524 &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]3525</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3526
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3527</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3528
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3529<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3530<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3531</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3532
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3533<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3534
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3535<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3536<pre>
3537 &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]3538</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3539
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3540<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3541<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3542 division of its two arguments.</p>
3543
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3544<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3545<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3546 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3547 values. Both arguments must have identical types.</p>
3548
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3549<h5>Semantics:</h5>
3550<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3551 This instruction always performs an unsigned division to get the
3552 remainder.</p>
3553
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3554<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3555 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3556
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3557<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3558
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3559<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3560<pre>
3561 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3562</pre>
3563
3564</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3565
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3566<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3567<div class="doc_subsubsection">
3568 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3569</div>
3570
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3571<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3572
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3573<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3574<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3575 &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]3576</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3577
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3578<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3579<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3580 division of its two operands. This instruction can also take
3581 <a href="#t_vector">vector</a> versions of the values in which case the
3582 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3583
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3584<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3585<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3586 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3587 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3588
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3589<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3590<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3591 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3592 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3593 a value. For more information about the difference,
3594 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3595 Math Forum</a>. For a table of how this is implemented in various languages,
3596 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3597 Wikipedia: modulo operation</a>.</p>
3598
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3599<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3600 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3601
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3602<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3603 Overflow also leads to undefined behavior; this is a rare case, but can
3604 occur, for example, by taking the remainder of a 32-bit division of
3605 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3606 lets srem be implemented using instructions that return both the result of
3607 the division and the remainder.)</p>
3608
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3609<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3610<pre>
3611 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3612</pre>
3613
3614</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3615
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3616<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3617<div class="doc_subsubsection">
3618 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3619
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3620<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3621
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3622<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3623<pre>
3624 &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]3625</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3626
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3627<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3628<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3629 its two operands.</p>
3630
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3631<h5>Arguments:</h5>
3632<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3633 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3634 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3635
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3636<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3637<p>This instruction returns the <i>remainder</i> of a division. The remainder
3638 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3639
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3640<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3641<pre>
3642 &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]3643</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3644
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3645</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3646
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3647<!-- ======================================================================= -->
3648<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3649Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3650
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3651<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3652
3653<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3654 program. They are generally very efficient instructions and can commonly be
3655 strength reduced from other instructions. They require two operands of the
3656 same type, execute an operation on them, and produce a single value. The
3657 resulting value is the same type as its operands.</p>
3658
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3659</div>
3660
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3661<!-- _______________________________________________________________________ -->
3662<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3663Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3664
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3665<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3666
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3667<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3668<pre>
3669 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3670</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3671
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3672<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3673<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3674 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3675
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3676<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3677<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3678 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3679 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3680
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3681<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3682<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3683 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3684 is (statically or dynamically) negative or equal to or larger than the number
3685 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3686 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3687 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3688
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3689<h5>Example:</h5>
3690<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3691 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3692 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3693 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3694 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3695 &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]3696</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3697
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3698</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3699
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3700<!-- _______________________________________________________________________ -->
3701<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3702Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3703
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3704<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3705
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3706<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3707<pre>
3708 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3709</pre>
3710
3711<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3712<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3713 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3714
3715<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3716<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3717 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3718 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3719
3720<h5>Semantics:</h5>
3721<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3722 significant bits of the result will be filled with zero bits after the shift.
3723 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3724 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3725 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3726 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3727
3728<h5>Example:</h5>
3729<pre>
3730 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3731 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3732 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3733 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3734 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3735 &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]3736</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3737
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3738</div>
3739
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3740<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3741<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3742Instruction</a> </div>
3743<div class="doc_text">
3744
3745<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3746<pre>
3747 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3748</pre>
3749
3750<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3751<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3752 operand shifted to the right a specified number of bits with sign
3753 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3754
3755<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3756<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3757 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3758 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3759
3760<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3761<p>This instruction always performs an arithmetic shift right operation, The
3762 most significant bits of the result will be filled with the sign bit
3763 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3764 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3765 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3766 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3767
3768<h5>Example:</h5>
3769<pre>
3770 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3771 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3772 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3773 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3774 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3775 &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]3776</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3777
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3778</div>
3779
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3780<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3781<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3782Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3783
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3784<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3785
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3786<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3787<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3788 &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]3789</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3790
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3791<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3792<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3793 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3794
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3795<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3796<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3797 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3798 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3799
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3800<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3801<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3802
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3803<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3804 <tbody>
3805 <tr>
3806 <td>In0</td>
3807 <td>In1</td>
3808 <td>Out</td>
3809 </tr>
3810 <tr>
3811 <td>0</td>
3812 <td>0</td>
3813 <td>0</td>
3814 </tr>
3815 <tr>
3816 <td>0</td>
3817 <td>1</td>
3818 <td>0</td>
3819 </tr>
3820 <tr>
3821 <td>1</td>
3822 <td>0</td>
3823 <td>0</td>
3824 </tr>
3825 <tr>
3826 <td>1</td>
3827 <td>1</td>
3828 <td>1</td>
3829 </tr>
3830 </tbody>
3831</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3832
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3833<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3834<pre>
3835 &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]3836 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3837 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3838</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3839</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3840<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3841<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3842
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3843<div class="doc_text">
3844
3845<h5>Syntax:</h5>
3846<pre>
3847 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3848</pre>
3849
3850<h5>Overview:</h5>
3851<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3852 two operands.</p>
3853
3854<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3855<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3856 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3857 values. Both arguments must have identical types.</p>
3858
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3859<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3860<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3861
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3862<table border="1" cellspacing="0" cellpadding="4">
3863 <tbody>
3864 <tr>
3865 <td>In0</td>
3866 <td>In1</td>
3867 <td>Out</td>
3868 </tr>
3869 <tr>
3870 <td>0</td>
3871 <td>0</td>
3872 <td>0</td>
3873 </tr>
3874 <tr>
3875 <td>0</td>
3876 <td>1</td>
3877 <td>1</td>
3878 </tr>
3879 <tr>
3880 <td>1</td>
3881 <td>0</td>
3882 <td>1</td>
3883 </tr>
3884 <tr>
3885 <td>1</td>
3886 <td>1</td>
3887 <td>1</td>
3888 </tr>
3889 </tbody>
3890</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3891
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3892<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3893<pre>
3894 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3895 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3896 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3897</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3898
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3899</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3900
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3901<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3902<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3903Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3904
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3905<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3906
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3907<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3908<pre>
3909 &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]3910</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3911
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3912<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3913<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3914 its two operands. The <tt>xor</tt> is used to implement the "one's
3915 complement" operation, which is the "~" operator in C.</p>
3916
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3917<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3918<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3919 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3920 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3921
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3922<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3923<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3924
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3925<table border="1" cellspacing="0" cellpadding="4">
3926 <tbody>
3927 <tr>
3928 <td>In0</td>
3929 <td>In1</td>
3930 <td>Out</td>
3931 </tr>
3932 <tr>
3933 <td>0</td>
3934 <td>0</td>
3935 <td>0</td>
3936 </tr>
3937 <tr>
3938 <td>0</td>
3939 <td>1</td>
3940 <td>1</td>
3941 </tr>
3942 <tr>
3943 <td>1</td>
3944 <td>0</td>
3945 <td>1</td>
3946 </tr>
3947 <tr>
3948 <td>1</td>
3949 <td>1</td>
3950 <td>0</td>
3951 </tr>
3952 </tbody>
3953</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3954
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3955<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3956<pre>
3957 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3958 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3959 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3960 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3961</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3962
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3963</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3964
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3965<!-- ======================================================================= -->
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3966<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3967 <a name="vectorops">Vector Operations</a>
3968</div>
3969
3970<div class="doc_text">
3971
3972<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3973 target-independent manner. These instructions cover the element-access and
3974 vector-specific operations needed to process vectors effectively. While LLVM
3975 does directly support these vector operations, many sophisticated algorithms
3976 will want to use target-specific intrinsics to take full advantage of a
3977 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3978
3979</div>
3980
3981<!-- _______________________________________________________________________ -->
3982<div class="doc_subsubsection">
3983 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3984</div>
3985
3986<div class="doc_text">
3987
3988<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3989<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3990 &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]3991</pre>
3992
3993<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3994<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3995 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3996
3997
3998<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3999<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4000 of <a href="#t_vector">vector</a> type. The second operand is an index
4001 indicating the position from which to extract the element. The index may be
4002 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4003
4004<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4005<p>The result is a scalar of the same type as the element type of
4006 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4007 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4008 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4009
4010<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4011<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4012 &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]4013</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4014
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4015</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4016
4017<!-- _______________________________________________________________________ -->
4018<div class="doc_subsubsection">
4019 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
4020</div>
4021
4022<div class="doc_text">
4023
4024<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4025<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]4026 &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]4027</pre>
4028
4029<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4030<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4031 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4032
4033<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4034<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4035 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4036 whose type must equal the element type of the first operand. The third
4037 operand is an index indicating the position at which to insert the value.
4038 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4039
4040<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4041<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4042 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4043 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4044 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4045
4046<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4047<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4048 &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]4049</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4050
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4051</div>
4052
4053<!-- _______________________________________________________________________ -->
4054<div class="doc_subsubsection">
4055 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
4056</div>
4057
4058<div class="doc_text">
4059
4060<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4061<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4062 &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]4063</pre>
4064
4065<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4066<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4067 from two input vectors, returning a vector with the same element type as the
4068 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4069
4070<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4071<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4072 with types that match each other. The third argument is a shuffle mask whose
4073 element type is always 'i32'. The result of the instruction is a vector
4074 whose length is the same as the shuffle mask and whose element type is the
4075 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4076
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4077<p>The shuffle mask operand is required to be a constant vector with either
4078 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4079
4080<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4081<p>The elements of the two input vectors are numbered from left to right across
4082 both of the vectors. The shuffle mask operand specifies, for each element of
4083 the result vector, which element of the two input vectors the result element
4084 gets. The element selector may be undef (meaning "don't care") and the
4085 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4086
4087<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4088<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4089 &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]4090 &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]4091 &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]4092 &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]4093 &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]4094 &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]4095 &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]4096 &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]4097</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4098
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4099</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]4100
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4101<!-- ======================================================================= -->
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4102<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4103 <a name="aggregateops">Aggregate Operations</a>
4104</div>
4105
4106<div class="doc_text">
4107
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4108<p>LLVM supports several instructions for working with
4109 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4110
4111</div>
4112
4113<!-- _______________________________________________________________________ -->
4114<div class="doc_subsubsection">
4115 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
4116</div>
4117
4118<div class="doc_text">
4119
4120<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4121<pre>
4122 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4123</pre>
4124
4125<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4126<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4127 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4128
4129<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4130<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4131 of <a href="#t_struct">struct</a>, <a href="#t_union">union</a> or
4132 <a href="#t_array">array</a> type. The operands are constant indices to
4133 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4134 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4135
4136<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4137<p>The result is the value at the position in the aggregate specified by the
4138 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4139
4140<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4141<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4142 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4143</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4144
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4145</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4146
4147<!-- _______________________________________________________________________ -->
4148<div class="doc_subsubsection">
4149 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
4150</div>
4151
4152<div class="doc_text">
4153
4154<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4155<pre>
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]4156 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt; <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4157</pre>
4158
4159<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4160<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4161 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4162
4163<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4164<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4165 of <a href="#t_struct">struct</a>, <a href="#t_union">union</a> or
4166 <a href="#t_array">array</a> type. The second operand is a first-class
4167 value to insert. The following operands are constant indices indicating
4168 the position at which to insert the value in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4169 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
4170 value to insert must have the same type as the value identified by the
4171 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4172
4173<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4174<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4175 that of <tt>val</tt> except that the value at the position specified by the
4176 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4177
4178<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4179<pre>
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]4180 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4181 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4182</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4183
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4184</div>
4185
4186
4187<!-- ======================================================================= -->
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4188<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4189 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4190</div>
4191
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4192<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4193
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4194<p>A key design point of an SSA-based representation is how it represents
4195 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4196 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4197 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4198
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4199</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4200
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4201<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4202<div class="doc_subsubsection">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4203 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
4204</div>
4205
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4206<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4207
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4208<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4209<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4210 &lt;result&gt; = alloca &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4211</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4212
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4213<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4214<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4215 currently executing function, to be automatically released when this function
4216 returns to its caller. The object is always allocated in the generic address
4217 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4218
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4219<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4220<p>The '<tt>alloca</tt>' instruction
4221 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4222 runtime stack, returning a pointer of the appropriate type to the program.
4223 If "NumElements" is specified, it is the number of elements allocated,
4224 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4225 specified, the value result of the allocation is guaranteed to be aligned to
4226 at least that boundary. If not specified, or if zero, the target can choose
4227 to align the allocation on any convenient boundary compatible with the
4228 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4229
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4230<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4231
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4232<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4233<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4234 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4235 memory is automatically released when the function returns. The
4236 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4237 variables that must have an address available. When the function returns
4238 (either with the <tt><a href="#i_ret">ret</a></tt>
4239 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4240 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4241
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4242<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4243<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4244 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4245 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4246 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4247 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4248</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4249
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4250</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4251
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4252<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4253<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
4254Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4255
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4256<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4257
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4258<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4259<pre>
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4260 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4261 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4262 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4263</pre>
4264
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4265<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4266<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4267
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4268<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4269<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4270 from which to load. The pointer must point to
4271 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4272 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4273 number or order of execution of this <tt>load</tt> with other <a
4274 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4275
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4276<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4277 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]4278 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4279 alignment for the target. It is the responsibility of the code emitter to
4280 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4281 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4282 produce less efficient code. An alignment of 1 is always safe.</p>
4283
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4284<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4285 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4286 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4287 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4288 and code generator that this load is not expected to be reused in the cache.
4289 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4290 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4291
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4292<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4293<p>The location of memory pointed to is loaded. If the value being loaded is of
4294 scalar type then the number of bytes read does not exceed the minimum number
4295 of bytes needed to hold all bits of the type. For example, loading an
4296 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4297 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4298 is undefined if the value was not originally written using a store of the
4299 same type.</p>
4300
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4301<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4302<pre>
4303 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4304 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4305 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4306</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4307
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4308</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4309
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4310<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4311<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
4312Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4313
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]4314<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4315
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4316<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4317<pre>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4318 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>] <i>; yields {void}</i>
4319 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>] <i>; yields {void}</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4320</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4321
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4322<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4323<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4324
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4325<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4326<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4327 and an address at which to store it. The type of the
4328 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4329 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4330 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4331 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4332 order of execution of this <tt>store</tt> with other <a
4333 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4334
4335<p>The optional constant "align" argument specifies the alignment of the
4336 operation (that is, the alignment of the memory address). A value of 0 or an
4337 omitted "align" argument means that the operation has the preferential
4338 alignment for the target. It is the responsibility of the code emitter to
4339 ensure that the alignment information is correct. Overestimating the
4340 alignment results in an undefined behavior. Underestimating the alignment may
4341 produce less efficient code. An alignment of 1 is always safe.</p>
4342
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4343<p>The optional !nontemporal metadata must reference a single metatadata
4344 name <index> corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4345 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4346 instruction tells the optimizer and code generator that this load is
4347 not expected to be reused in the cache. The code generator may
4348 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4349 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4350
4351
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4352<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4353<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4354 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4355 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4356 does not exceed the minimum number of bytes needed to hold all bits of the
4357 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4358 writing a value of a type like <tt>i20</tt> with a size that is not an
4359 integral number of bytes, it is unspecified what happens to the extra bits
4360 that do not belong to the type, but they will typically be overwritten.</p>
4361
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4362<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4363<pre>
4364 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4365 store i32 3, i32* %ptr <i>; yields {void}</i>
4366 %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]4367</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4368
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4369</div>
4370
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4371<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4372<div class="doc_subsubsection">
4373 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
4374</div>
4375
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4376<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4377
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4378<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4379<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4380 &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]4381 &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]4382</pre>
4383
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4384<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4385<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4386 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4387 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4388
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4389<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4390<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4391 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4392 elements of the aggregate object are indexed. The interpretation of each
4393 index is dependent on the type being indexed into. The first index always
4394 indexes the pointer value given as the first argument, the second index
4395 indexes a value of the type pointed to (not necessarily the value directly
4396 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4397 indexed into must be a pointer value, subsequent types can be arrays,
4398 vectors, structs and unions. Note that subsequent types being indexed into
4399 can never be pointers, since that would require loading the pointer before
4400 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4401
4402<p>The type of each index argument depends on the type it is indexing into.
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4403 When indexing into a (optionally packed) structure or union, only <tt>i32</tt>
4404 integer <b>constants</b> are allowed. When indexing into an array, pointer
4405 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]4406 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4407
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4408<p>For example, let's consider a C code fragment and how it gets compiled to
4409 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4410
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4411<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4412<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4413struct RT {
4414 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4415 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4416 char C;
4417};
4418struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4419 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4420 double Y;
4421 struct RT Z;
4422};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4423
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4424int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4425 return &amp;s[1].Z.B[5][13];
4426}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4427</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4428</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4429
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4430<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4431
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4432<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4433<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]4434%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4435%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4436
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4437define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4438entry:
4439 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4440 ret i32* %reg
4441}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4442</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4443</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4444
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4445<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4446<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]4447 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4448 }</tt>' type, a structure. The second index indexes into the third element
4449 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4450 i8 }</tt>' type, another structure. The third index indexes into the second
4451 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4452 array. The two dimensions of the array are subscripted into, yielding an
4453 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4454 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4455
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4456<p>Note that it is perfectly legal to index partially through a structure,
4457 returning a pointer to an inner element. Because of this, the LLVM code for
4458 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4459
4460<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4461 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4462 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4463 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4464 %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]4465 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4466 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4467 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4468 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4469</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]4470
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4471<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]4472 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4473 base pointer is not an <i>in bounds</i> address of an allocated object,
4474 or if any of the addresses that would be formed by successive addition of
4475 the offsets implied by the indices to the base address with infinitely
4476 precise arithmetic are not an <i>in bounds</i> address of that allocated
4477 object. The <i>in bounds</i> addresses for an allocated object are all
4478 the addresses that point into the object, plus the address one byte past
4479 the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4480
4481<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4482 the base address with silently-wrapping two's complement arithmetic, and
4483 the result value of the <tt>getelementptr</tt> may be outside the object
4484 pointed to by the base pointer. The result value may not necessarily be
4485 used to access memory though, even if it happens to point into allocated
4486 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4487 section for more information.</p>
4488
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4489<p>The getelementptr instruction is often confusing. For some more insight into
4490 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4491
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4492<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4493<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4494 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4495 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4496 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4497 %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]4498 <i>; yields i8*:eptr</i>
4499 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]4500 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]4501 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4502</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4503
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4504</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4505
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4506<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4507<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4508</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4509
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4510<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4511
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4512<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4513 which all take a single operand and a type. They perform various bit
4514 conversions on the operand.</p>
4515
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4516</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4517
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4518<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4519<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4520 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4521</div>
4522<div class="doc_text">
4523
4524<h5>Syntax:</h5>
4525<pre>
4526 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4527</pre>
4528
4529<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4530<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4531 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4532
4533<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4534<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4535 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4536 size and type of the result, which must be
4537 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4538 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4539 allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4540
4541<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4542<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4543 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4544 source size must be larger than the destination size, <tt>trunc</tt> cannot
4545 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4546
4547<h5>Example:</h5>
4548<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4549 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4550 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4551 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4552</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4553
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4554</div>
4555
4556<!-- _______________________________________________________________________ -->
4557<div class="doc_subsubsection">
4558 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4559</div>
4560<div class="doc_text">
4561
4562<h5>Syntax:</h5>
4563<pre>
4564 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4565</pre>
4566
4567<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4568<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4569 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4570
4571
4572<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4573<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4574 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4575 also be of <a href="#t_integer">integer</a> type. The bit size of the
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4576 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4577 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4578
4579<h5>Semantics:</h5>
4580<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]4581 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4582
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]4583<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]4584
4585<h5>Example:</h5>
4586<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4587 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4588 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4589</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4590
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4591</div>
4592
4593<!-- _______________________________________________________________________ -->
4594<div class="doc_subsubsection">
4595 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4596</div>
4597<div class="doc_text">
4598
4599<h5>Syntax:</h5>
4600<pre>
4601 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4602</pre>
4603
4604<h5>Overview:</h5>
4605<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4606
4607<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4608<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4609 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4610 also be of <a href="#t_integer">integer</a> type. The bit size of the
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4611 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4612 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4613
4614<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4615<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4616 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4617 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4618
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4619<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]4620
4621<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4622<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4623 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4624 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4625</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4626
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4627</div>
4628
4629<!-- _______________________________________________________________________ -->
4630<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4631 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4632</div>
4633
4634<div class="doc_text">
4635
4636<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4637<pre>
4638 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4639</pre>
4640
4641<h5>Overview:</h5>
4642<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4643 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4644
4645<h5>Arguments:</h5>
4646<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4647 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4648 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]4649 <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]4650 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4651
4652<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4653<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4654 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4655 <a href="#t_floating">floating point</a> type. If the value cannot fit
4656 within the destination type, <tt>ty2</tt>, then the results are
4657 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4658
4659<h5>Example:</h5>
4660<pre>
4661 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4662 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4663</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4664
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4665</div>
4666
4667<!-- _______________________________________________________________________ -->
4668<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4669 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4670</div>
4671<div class="doc_text">
4672
4673<h5>Syntax:</h5>
4674<pre>
4675 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4676</pre>
4677
4678<h5>Overview:</h5>
4679<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]4680 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4681
4682<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4683<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4684 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4685 a <a href="#t_floating">floating point</a> type to cast it to. The source
4686 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4687
4688<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4689<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4690 <a href="#t_floating">floating point</a> type to a larger
4691 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4692 used to make a <i>no-op cast</i> because it always changes bits. Use
4693 <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]4694
4695<h5>Example:</h5>
4696<pre>
4697 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4698 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4699</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4700
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4701</div>
4702
4703<!-- _______________________________________________________________________ -->
4704<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]4705 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4706</div>
4707<div class="doc_text">
4708
4709<h5>Syntax:</h5>
4710<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4711 &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]4712</pre>
4713
4714<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4715<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4716 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4717
4718<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4719<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4720 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4721 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4722 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4723 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4724
4725<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4726<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4727 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4728 towards zero) unsigned integer value. If the value cannot fit
4729 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4730
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4731<h5>Example:</h5>
4732<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4733 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4734 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4735 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4736</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4737
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4738</div>
4739
4740<!-- _______________________________________________________________________ -->
4741<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4742 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4743</div>
4744<div class="doc_text">
4745
4746<h5>Syntax:</h5>
4747<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4748 &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]4749</pre>
4750
4751<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4752<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4753 <a href="#t_floating">floating point</a> <tt>value</tt> to
4754 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4755
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4756<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4757<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4758 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4759 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4760 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4761 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4762
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4763<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4764<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4765 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4766 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4767 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4768
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4769<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4770<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4771 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4772 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4773 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4774</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4775
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4776</div>
4777
4778<!-- _______________________________________________________________________ -->
4779<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4780 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4781</div>
4782<div class="doc_text">
4783
4784<h5>Syntax:</h5>
4785<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4786 &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]4787</pre>
4788
4789<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4790<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4791 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4792
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4793<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4794<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]4795 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4796 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4797 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4798 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4799
4800<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4801<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4802 integer quantity and converts it to the corresponding floating point
4803 value. If the value cannot fit in the floating point value, the results are
4804 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4805
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4806<h5>Example:</h5>
4807<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4808 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4809 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4810</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4811
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4812</div>
4813
4814<!-- _______________________________________________________________________ -->
4815<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4816 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4817</div>
4818<div class="doc_text">
4819
4820<h5>Syntax:</h5>
4821<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4822 &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]4823</pre>
4824
4825<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4826<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4827 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4828
4829<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4830<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]4831 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4832 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4833 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4834 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4835
4836<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4837<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4838 quantity and converts it to the corresponding floating point value. If the
4839 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4840
4841<h5>Example:</h5>
4842<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4843 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4844 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4845</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4846
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4847</div>
4848
4849<!-- _______________________________________________________________________ -->
4850<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4851 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4852</div>
4853<div class="doc_text">
4854
4855<h5>Syntax:</h5>
4856<pre>
4857 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4858</pre>
4859
4860<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4861<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4862 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4863
4864<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4865<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4866 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4867 <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]4868
4869<h5>Semantics:</h5>
4870<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4871 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4872 truncating or zero extending that value to the size of the integer type. If
4873 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4874 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4875 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4876 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4877
4878<h5>Example:</h5>
4879<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4880 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4881 %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]4882</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4883
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4884</div>
4885
4886<!-- _______________________________________________________________________ -->
4887<div class="doc_subsubsection">
4888 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4889</div>
4890<div class="doc_text">
4891
4892<h5>Syntax:</h5>
4893<pre>
4894 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4895</pre>
4896
4897<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4898<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4899 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4900
4901<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4902<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4903 value to cast, and a type to cast it to, which must be a
4904 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4905
4906<h5>Semantics:</h5>
4907<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4908 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4909 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4910 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4911 than the size of a pointer then a zero extension is done. If they are the
4912 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4913
4914<h5>Example:</h5>
4915<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4916 %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]4917 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4918 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4919</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4920
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4921</div>
4922
4923<!-- _______________________________________________________________________ -->
4924<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4925 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4926</div>
4927<div class="doc_text">
4928
4929<h5>Syntax:</h5>
4930<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4931 &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]4932</pre>
4933
4934<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4935<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4936 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4937
4938<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4939<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4940 non-aggregate first class value, and a type to cast it to, which must also be
4941 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4942 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4943 identical. If the source type is a pointer, the destination type must also be
4944 a pointer. This instruction supports bitwise conversion of vectors to
4945 integers and to vectors of other types (as long as they have the same
4946 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4947
4948<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4949<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4950 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4951 this conversion. The conversion is done as if the <tt>value</tt> had been
4952 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4953 be converted to other pointer types with this instruction. To convert
4954 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4955 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4956
4957<h5>Example:</h5>
4958<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4959 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4960 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4961 %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]4962</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4963
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4964</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4965
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4966<!-- ======================================================================= -->
4967<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4968
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4969<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4970
4971<p>The instructions in this category are the "miscellaneous" instructions, which
4972 defy better classification.</p>
4973
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4974</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4975
4976<!-- _______________________________________________________________________ -->
4977<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4978</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4979
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4980<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4981
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4982<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4983<pre>
4984 &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]4985</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4986
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4987<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4988<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4989 boolean values based on comparison of its two integer, integer vector, or
4990 pointer operands.</p>
4991
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4992<h5>Arguments:</h5>
4993<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4994 the condition code indicating the kind of comparison to perform. It is not a
4995 value, just a keyword. The possible condition code are:</p>
4996
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4997<ol>
4998 <li><tt>eq</tt>: equal</li>
4999 <li><tt>ne</tt>: not equal </li>
5000 <li><tt>ugt</tt>: unsigned greater than</li>
5001 <li><tt>uge</tt>: unsigned greater or equal</li>
5002 <li><tt>ult</tt>: unsigned less than</li>
5003 <li><tt>ule</tt>: unsigned less or equal</li>
5004 <li><tt>sgt</tt>: signed greater than</li>
5005 <li><tt>sge</tt>: signed greater or equal</li>
5006 <li><tt>slt</tt>: signed less than</li>
5007 <li><tt>sle</tt>: signed less or equal</li>
5008</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5009
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]5010<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5011 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5012 typed. They must also be identical types.</p>
5013
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5014<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5015<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5016 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5017 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]5018 result, as follows:</p>
5019
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5020<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5021 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5022 <tt>false</tt> otherwise. No sign interpretation is necessary or
5023 performed.</li>
5024
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5025 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5026 <tt>false</tt> otherwise. No sign interpretation is necessary or
5027 performed.</li>
5028
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5029 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5030 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5031
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5032 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5033 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5034 to <tt>op2</tt>.</li>
5035
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5036 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5037 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5038
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5039 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5040 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5041
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5042 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5043 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5044
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5045 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5046 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5047 to <tt>op2</tt>.</li>
5048
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5049 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5050 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5051
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5052 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5053 <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]5054</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5055
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5056<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5057 values are compared as if they were integers.</p>
5058
5059<p>If the operands are integer vectors, then they are compared element by
5060 element. The result is an <tt>i1</tt> vector with the same number of elements
5061 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5062
5063<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5064<pre>
5065 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5066 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5067 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5068 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5069 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5070 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5071</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5072
5073<p>Note that the code generator does not yet support vector types with
5074 the <tt>icmp</tt> instruction.</p>
5075
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5076</div>
5077
5078<!-- _______________________________________________________________________ -->
5079<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5080</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5081
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5082<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5083
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5084<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5085<pre>
5086 &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]5087</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5088
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5089<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5090<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5091 values based on comparison of its operands.</p>
5092
5093<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]5094(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5095
5096<p>If the operands are floating point vectors, then the result type is a vector
5097 of boolean with the same number of elements as the operands being
5098 compared.</p>
5099
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5100<h5>Arguments:</h5>
5101<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5102 the condition code indicating the kind of comparison to perform. It is not a
5103 value, just a keyword. The possible condition code are:</p>
5104
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5105<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5106 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5107 <li><tt>oeq</tt>: ordered and equal</li>
5108 <li><tt>ogt</tt>: ordered and greater than </li>
5109 <li><tt>oge</tt>: ordered and greater than or equal</li>
5110 <li><tt>olt</tt>: ordered and less than </li>
5111 <li><tt>ole</tt>: ordered and less than or equal</li>
5112 <li><tt>one</tt>: ordered and not equal</li>
5113 <li><tt>ord</tt>: ordered (no nans)</li>
5114 <li><tt>ueq</tt>: unordered or equal</li>
5115 <li><tt>ugt</tt>: unordered or greater than </li>
5116 <li><tt>uge</tt>: unordered or greater than or equal</li>
5117 <li><tt>ult</tt>: unordered or less than </li>
5118 <li><tt>ule</tt>: unordered or less than or equal</li>
5119 <li><tt>une</tt>: unordered or not equal</li>
5120 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5121 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5122</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5123
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5124<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5125 <i>unordered</i> means that either operand may be a QNAN.</p>
5126
5127<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5128 a <a href="#t_floating">floating point</a> type or
5129 a <a href="#t_vector">vector</a> of floating point type. They must have
5130 identical types.</p>
5131
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5132<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]5133<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5134 according to the condition code given as <tt>cond</tt>. If the operands are
5135 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5136 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5137 follows:</p>
5138
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5139<ol>
5140 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5141
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5142 <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]5143 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5144
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5145 <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]5146 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5147
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5148 <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]5149 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5150
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5151 <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]5152 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5153
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5154 <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]5155 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5156
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5157 <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]5158 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5159
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5160 <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]5161
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5162 <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]5163 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5164
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5165 <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]5166 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5167
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5168 <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]5169 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5170
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5171 <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]5172 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5173
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5174 <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]5175 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5176
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5177 <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]5178 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5179
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5180 <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]5181
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5182 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5183</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5184
5185<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5186<pre>
5187 &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]5188 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5189 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5190 &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]5191</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5192
5193<p>Note that the code generator does not yet support vector types with
5194 the <tt>fcmp</tt> instruction.</p>
5195
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5196</div>
5197
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5198<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]5199<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5200 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
5201</div>
5202
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5203<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5204
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5205<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5206<pre>
5207 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5208</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5209
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5210<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5211<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5212 SSA graph representing the function.</p>
5213
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5214<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5215<p>The type of the incoming values is specified with the first type field. After
5216 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5217 one pair for each predecessor basic block of the current block. Only values
5218 of <a href="#t_firstclass">first class</a> type may be used as the value
5219 arguments to the PHI node. Only labels may be used as the label
5220 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5221
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5222<p>There must be no non-phi instructions between the start of a basic block and
5223 the PHI instructions: i.e. PHI instructions must be first in a basic
5224 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5225
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5226<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5227 occur on the edge from the corresponding predecessor block to the current
5228 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5229 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]5230
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5231<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5232<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5233 specified by the pair corresponding to the predecessor basic block that
5234 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5235
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5236<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5237<pre>
5238Loop: ; Infinite loop that counts from 0 on up...
5239 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5240 %nextindvar = add i32 %indvar, 1
5241 br label %Loop
5242</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5243
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5244</div>
5245
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5246<!-- _______________________________________________________________________ -->
5247<div class="doc_subsubsection">
5248 <a name="i_select">'<tt>select</tt>' Instruction</a>
5249</div>
5250
5251<div class="doc_text">
5252
5253<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5254<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5255 &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>
5256
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5257 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5258</pre>
5259
5260<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5261<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5262 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5263
5264
5265<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5266<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5267 values indicating the condition, and two values of the
5268 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5269 vectors and the condition is a scalar, then entire vectors are selected, not
5270 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5271
5272<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5273<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5274 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5275
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5276<p>If the condition is a vector of i1, then the value arguments must be vectors
5277 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5278
5279<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5280<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5281 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5282</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5283
5284<p>Note that the code generator does not yet support conditions
5285 with vector type.</p>
5286
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5287</div>
5288
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5289<!-- _______________________________________________________________________ -->
5290<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5291 <a name="i_call">'<tt>call</tt>' Instruction</a>
5292</div>
5293
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5294<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5295
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5296<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5297<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]5298 &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]5299</pre>
5300
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5301<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5302<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5303
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5304<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5305<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5306
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5307<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5308 <li>The optional "tail" marker indicates that the callee function does not
5309 access any allocas or varargs in the caller. Note that calls may be
5310 marked "tail" even if they do not occur before
5311 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5312 present, the function call is eligible for tail call optimization,
5313 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Chengdc444e92010-03-08 21:05:02 +0000[diff] [blame]5314 optimized into a jump</a>. The code generator may optimize calls marked
5315 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5316 sibling call optimization</a> when the caller and callee have
5317 matching signatures, or 2) forced tail call optimization when the
5318 following extra requirements are met:
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5319 <ul>
5320 <li>Caller and callee both have the calling
5321 convention <tt>fastcc</tt>.</li>
5322 <li>The call is in tail position (ret immediately follows call and ret
5323 uses value of call or is void).</li>
5324 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohmanfbbee8d2010-03-02 01:08:11 +0000[diff] [blame]5325 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5326 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5327 constraints are met.</a></li>
5328 </ul>
5329 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5330
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5331 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5332 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5333 defaults to using C calling conventions. The calling convention of the
5334 call must match the calling convention of the target function, or else the
5335 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5336
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5337 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5338 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5339 '<tt>inreg</tt>' attributes are valid here.</li>
5340
5341 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5342 type of the return value. Functions that return no value are marked
5343 <tt><a href="#t_void">void</a></tt>.</li>
5344
5345 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5346 being invoked. The argument types must match the types implied by this
5347 signature. This type can be omitted if the function is not varargs and if
5348 the function type does not return a pointer to a function.</li>
5349
5350 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5351 be invoked. In most cases, this is a direct function invocation, but
5352 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5353 to function value.</li>
5354
5355 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]5356 signature argument types and parameter attributes. All arguments must be
5357 of <a href="#t_firstclass">first class</a> type. If the function
5358 signature indicates the function accepts a variable number of arguments,
5359 the extra arguments can be specified.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5360
5361 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5362 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5363 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5364</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5365
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5366<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5367<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5368 a specified function, with its incoming arguments bound to the specified
5369 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5370 function, control flow continues with the instruction after the function
5371 call, and the return value of the function is bound to the result
5372 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5373
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5374<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5375<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]5376 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]5377 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
5378 %X = tail call i32 @foo() <i>; yields i32</i>
5379 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5380 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]5381
5382 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5383 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]5384 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5385 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]5386 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]5387 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5388</pre>
5389
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5390<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]5391standard C99 library as being the C99 library functions, and may perform
5392optimizations or generate code for them under that assumption. This is
5393something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5394freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5395
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5396</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5397
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5398<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5399<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]5400 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5401</div>
5402
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5403<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5404
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5405<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5406<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5407 &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]5408</pre>
5409
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5410<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5411<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5412 the "variable argument" area of a function call. It is used to implement the
5413 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5414
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5415<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5416<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5417 argument. It returns a value of the specified argument type and increments
5418 the <tt>va_list</tt> to point to the next argument. The actual type
5419 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5420
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5421<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5422<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5423 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5424 to the next argument. For more information, see the variable argument
5425 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5426
5427<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]5428 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5429 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5430
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5431<p><tt>va_arg</tt> is an LLVM instruction instead of
5432 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5433 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5434
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5435<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5436<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5437
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5438<p>Note that the code generator does not yet fully support va_arg on many
5439 targets. Also, it does not currently support va_arg with aggregate types on
5440 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]5441
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5442</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5443
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5444<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]5445<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
5446<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5447
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5448<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5449
5450<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5451 well known names and semantics and are required to follow certain
5452 restrictions. Overall, these intrinsics represent an extension mechanism for
5453 the LLVM language that does not require changing all of the transformations
5454 in LLVM when adding to the language (or the bitcode reader/writer, the
5455 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5456
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5457<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5458 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5459 begin with this prefix. Intrinsic functions must always be external
5460 functions: you cannot define the body of intrinsic functions. Intrinsic
5461 functions may only be used in call or invoke instructions: it is illegal to
5462 take the address of an intrinsic function. Additionally, because intrinsic
5463 functions are part of the LLVM language, it is required if any are added that
5464 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5465
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5466<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5467 family of functions that perform the same operation but on different data
5468 types. Because LLVM can represent over 8 million different integer types,
5469 overloading is used commonly to allow an intrinsic function to operate on any
5470 integer type. One or more of the argument types or the result type can be
5471 overloaded to accept any integer type. Argument types may also be defined as
5472 exactly matching a previous argument's type or the result type. This allows
5473 an intrinsic function which accepts multiple arguments, but needs all of them
5474 to be of the same type, to only be overloaded with respect to a single
5475 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5476
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5477<p>Overloaded intrinsics will have the names of its overloaded argument types
5478 encoded into its function name, each preceded by a period. Only those types
5479 which are overloaded result in a name suffix. Arguments whose type is matched
5480 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5481 can take an integer of any width and returns an integer of exactly the same
5482 integer width. This leads to a family of functions such as
5483 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5484 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5485 suffix is required. Because the argument's type is matched against the return
5486 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5487
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5488<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5489 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5490
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5491</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5492
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5493<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5494<div class="doc_subsection">
5495 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
5496</div>
5497
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5498<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5499
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5500<p>Variable argument support is defined in LLVM with
5501 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5502 intrinsic functions. These functions are related to the similarly named
5503 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5504
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5505<p>All of these functions operate on arguments that use a target-specific value
5506 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5507 not define what this type is, so all transformations should be prepared to
5508 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5509
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]5510<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]5511 instruction and the variable argument handling intrinsic functions are
5512 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5513
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5514<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5515<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5516define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5517 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5518 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5519 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5520 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5521
5522 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5523 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5524
5525 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5526 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5527 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5528 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5529 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5530
5531 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5532 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5533 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5534}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5535
5536declare void @llvm.va_start(i8*)
5537declare void @llvm.va_copy(i8*, i8*)
5538declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5539</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5540</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5541
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5542</div>
5543
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5544<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5545<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5546 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5547</div>
5548
5549
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5550<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5551
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5552<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5553<pre>
5554 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5555</pre>
5556
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5557<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5558<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5559 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]5560
5561<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5562<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]5563
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5564<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5565<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]5566 macro available in C. In a target-dependent way, it initializes
5567 the <tt>va_list</tt> element to which the argument points, so that the next
5568 call to <tt>va_arg</tt> will produce the first variable argument passed to
5569 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5570 need to know the last argument of the function as the compiler can figure
5571 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5572
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5573</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5574
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5575<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5576<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5577 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5578</div>
5579
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5580<div class="doc_text">
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5581
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5582<h5>Syntax:</h5>
5583<pre>
5584 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5585</pre>
5586
5587<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5588<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5589 which has been initialized previously
5590 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5591 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5592
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5593<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5594<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]5595
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5596<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5597<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]5598 macro available in C. In a target-dependent way, it destroys
5599 the <tt>va_list</tt> element to which the argument points. Calls
5600 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5601 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5602 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5603
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5604</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5605
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5606<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5607<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5608 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5609</div>
5610
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5611<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5612
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5613<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5614<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5615 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5616</pre>
5617
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5618<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5619<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5620 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5621
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5622<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5623<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]5624 The second argument is a pointer to a <tt>va_list</tt> element to copy
5625 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5626
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5627<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5628<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]5629 macro available in C. In a target-dependent way, it copies the
5630 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5631 element. This intrinsic is necessary because
5632 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5633 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5634
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5635</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5636
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5637<!-- ======================================================================= -->
5638<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5639 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5640</div>
5641
5642<div class="doc_text">
5643
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5644<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5645Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5646intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5647roots on the stack</a>, as well as garbage collector implementations that
5648require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5649barriers. Front-ends for type-safe garbage collected languages should generate
5650these intrinsics to make use of the LLVM garbage collectors. For more details,
5651see <a href="GarbageCollection.html">Accurate Garbage Collection with
5652LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5653
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5654<p>The garbage collection intrinsics only operate on objects in the generic
5655 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5656
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5657</div>
5658
5659<!-- _______________________________________________________________________ -->
5660<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5661 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5662</div>
5663
5664<div class="doc_text">
5665
5666<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5667<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5668 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5669</pre>
5670
5671<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]5672<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]5673 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5674
5675<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5676<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5677 root pointer. The second pointer (which must be either a constant or a
5678 global value address) contains the meta-data to be associated with the
5679 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5680
5681<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]5682<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]5683 location. At compile-time, the code generator generates information to allow
5684 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5685 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5686 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5687
5688</div>
5689
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5690<!-- _______________________________________________________________________ -->
5691<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5692 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5693</div>
5694
5695<div class="doc_text">
5696
5697<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5698<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5699 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5700</pre>
5701
5702<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5703<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5704 locations, allowing garbage collector implementations that require read
5705 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5706
5707<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5708<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]5709 allocated from the garbage collector. The first object is a pointer to the
5710 start of the referenced object, if needed by the language runtime (otherwise
5711 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5712
5713<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5714<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5715 instruction, but may be replaced with substantially more complex code by the
5716 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5717 may only be used in a function which <a href="#gc">specifies a GC
5718 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5719
5720</div>
5721
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5722<!-- _______________________________________________________________________ -->
5723<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5724 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5725</div>
5726
5727<div class="doc_text">
5728
5729<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5730<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5731 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5732</pre>
5733
5734<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5735<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5736 locations, allowing garbage collector implementations that require write
5737 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5738
5739<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5740<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]5741 object to store it to, and the third is the address of the field of Obj to
5742 store to. If the runtime does not require a pointer to the object, Obj may
5743 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5744
5745<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5746<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5747 instruction, but may be replaced with substantially more complex code by the
5748 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5749 may only be used in a function which <a href="#gc">specifies a GC
5750 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5751
5752</div>
5753
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5754<!-- ======================================================================= -->
5755<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5756 <a name="int_codegen">Code Generator Intrinsics</a>
5757</div>
5758
5759<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5760
5761<p>These intrinsics are provided by LLVM to expose special features that may
5762 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5763
5764</div>
5765
5766<!-- _______________________________________________________________________ -->
5767<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5768 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5769</div>
5770
5771<div class="doc_text">
5772
5773<h5>Syntax:</h5>
5774<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5775 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5776</pre>
5777
5778<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5779<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5780 target-specific value indicating the return address of the current function
5781 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5782
5783<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5784<p>The argument to this intrinsic indicates which function to return the address
5785 for. Zero indicates the calling function, one indicates its caller, etc.
5786 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5787
5788<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5789<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5790 indicating the return address of the specified call frame, or zero if it
5791 cannot be identified. The value returned by this intrinsic is likely to be
5792 incorrect or 0 for arguments other than zero, so it should only be used for
5793 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5794
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5795<p>Note that calling this intrinsic does not prevent function inlining or other
5796 aggressive transformations, so the value returned may not be that of the
5797 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5798
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5799</div>
5800
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5801<!-- _______________________________________________________________________ -->
5802<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5803 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5804</div>
5805
5806<div class="doc_text">
5807
5808<h5>Syntax:</h5>
5809<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5810 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5811</pre>
5812
5813<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5814<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5815 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5816
5817<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5818<p>The argument to this intrinsic indicates which function to return the frame
5819 pointer for. Zero indicates the calling function, one indicates its caller,
5820 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5821
5822<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5823<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5824 indicating the frame address of the specified call frame, or zero if it
5825 cannot be identified. The value returned by this intrinsic is likely to be
5826 incorrect or 0 for arguments other than zero, so it should only be used for
5827 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5828
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5829<p>Note that calling this intrinsic does not prevent function inlining or other
5830 aggressive transformations, so the value returned may not be that of the
5831 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5832
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5833</div>
5834
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5835<!-- _______________________________________________________________________ -->
5836<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5837 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5838</div>
5839
5840<div class="doc_text">
5841
5842<h5>Syntax:</h5>
5843<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5844 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5845</pre>
5846
5847<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5848<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5849 of the function stack, for use
5850 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5851 useful for implementing language features like scoped automatic variable
5852 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5853
5854<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5855<p>This intrinsic returns a opaque pointer value that can be passed
5856 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5857 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5858 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5859 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5860 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5861 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5862
5863</div>
5864
5865<!-- _______________________________________________________________________ -->
5866<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5867 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5868</div>
5869
5870<div class="doc_text">
5871
5872<h5>Syntax:</h5>
5873<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5874 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5875</pre>
5876
5877<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5878<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5879 the function stack to the state it was in when the
5880 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5881 executed. This is useful for implementing language features like scoped
5882 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5883
5884<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5885<p>See the description
5886 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5887
5888</div>
5889
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5890<!-- _______________________________________________________________________ -->
5891<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5892 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5893</div>
5894
5895<div class="doc_text">
5896
5897<h5>Syntax:</h5>
5898<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5899 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5900</pre>
5901
5902<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5903<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5904 insert a prefetch instruction if supported; otherwise, it is a noop.
5905 Prefetches have no effect on the behavior of the program but can change its
5906 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5907
5908<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5909<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5910 specifier determining if the fetch should be for a read (0) or write (1),
5911 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5912 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5913 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5914
5915<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5916<p>This intrinsic does not modify the behavior of the program. In particular,
5917 prefetches cannot trap and do not produce a value. On targets that support
5918 this intrinsic, the prefetch can provide hints to the processor cache for
5919 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5920
5921</div>
5922
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5923<!-- _______________________________________________________________________ -->
5924<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5925 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5926</div>
5927
5928<div class="doc_text">
5929
5930<h5>Syntax:</h5>
5931<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5932 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5933</pre>
5934
5935<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5936<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5937 Counter (PC) in a region of code to simulators and other tools. The method
5938 is target specific, but it is expected that the marker will use exported
5939 symbols to transmit the PC of the marker. The marker makes no guarantees
5940 that it will remain with any specific instruction after optimizations. It is
5941 possible that the presence of a marker will inhibit optimizations. The
5942 intended use is to be inserted after optimizations to allow correlations of
5943 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5944
5945<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5946<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5947
5948<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5949<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5950 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5951
5952</div>
5953
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5954<!-- _______________________________________________________________________ -->
5955<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5956 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5957</div>
5958
5959<div class="doc_text">
5960
5961<h5>Syntax:</h5>
5962<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5963 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5964</pre>
5965
5966<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5967<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5968 counter register (or similar low latency, high accuracy clocks) on those
5969 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5970 should map to RPCC. As the backing counters overflow quickly (on the order
5971 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5972
5973<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5974<p>When directly supported, reading the cycle counter should not modify any
5975 memory. Implementations are allowed to either return a application specific
5976 value or a system wide value. On backends without support, this is lowered
5977 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5978
5979</div>
5980
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5981<!-- ======================================================================= -->
5982<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5983 <a name="int_libc">Standard C Library Intrinsics</a>
5984</div>
5985
5986<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5987
5988<p>LLVM provides intrinsics for a few important standard C library functions.
5989 These intrinsics allow source-language front-ends to pass information about
5990 the alignment of the pointer arguments to the code generator, providing
5991 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5992
5993</div>
5994
5995<!-- _______________________________________________________________________ -->
5996<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5997 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5998</div>
5999
6000<div class="doc_text">
6001
6002<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6003<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]6004 integer bit width and for different address spaces. Not all targets support
6005 all bit widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6006
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6007<pre>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6008 declare void @llvm.memcpy.p0i8.p0i8.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
6009 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
6010 declare void @llvm.memcpy.p0i8.p0i8.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
6011 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6012</pre>
6013
6014<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6015<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6016 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6017
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6018<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6019 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6020 and the pointers can be in specified address spaces.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6021
6022<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6023
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6024<p>The first argument is a pointer to the destination, the second is a pointer
6025 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6026 number of bytes to copy, the fourth argument is the alignment of the
6027 source and destination locations, and the fifth is a boolean indicating a
6028 volatile access.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6029
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6030<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]6031 then the caller guarantees that both the source and destination pointers are
6032 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6033
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6034<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6035 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6036 The detailed access behavior is not very cleanly specified and it is unwise
6037 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6038
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6039<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6040
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6041<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6042 source location to the destination location, which are not allowed to
6043 overlap. It copies "len" bytes of memory over. If the argument is known to
6044 be aligned to some boundary, this can be specified as the fourth argument,
6045 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6046
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6047</div>
6048
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6049<!-- _______________________________________________________________________ -->
6050<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6051 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6052</div>
6053
6054<div class="doc_text">
6055
6056<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6057<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]6058 width and for different address space. Not all targets support all bit
6059 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6060
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6061<pre>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6062 declare void @llvm.memmove.p0i8.p0i8.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
6063 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
6064 declare void @llvm.memmove.p0i8.p0i8.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
6065 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6066</pre>
6067
6068<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6069<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6070 source location to the destination location. It is similar to the
6071 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6072 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6073
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6074<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6075 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6076 and the pointers can be in specified address spaces.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6077
6078<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6079
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6080<p>The first argument is a pointer to the destination, the second is a pointer
6081 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6082 number of bytes to copy, the fourth argument is the alignment of the
6083 source and destination locations, and the fifth is a boolean indicating a
6084 volatile access.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6085
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6086<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]6087 then the caller guarantees that the source and destination pointers are
6088 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6089
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6090<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6091 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6092 The detailed access behavior is not very cleanly specified and it is unwise
6093 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6094
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6095<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6096
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6097<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6098 source location to the destination location, which may overlap. It copies
6099 "len" bytes of memory over. If the argument is known to be aligned to some
6100 boundary, this can be specified as the fourth argument, otherwise it should
6101 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6102
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6103</div>
6104
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6105<!-- _______________________________________________________________________ -->
6106<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6107 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6108</div>
6109
6110<div class="doc_text">
6111
6112<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6113<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
Mon P Wange88909b2010-04-07 06:35:53 +0000[diff] [blame]6114 width and for different address spaces. Not all targets support all bit
6115 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6116
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6117<pre>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6118 declare void @llvm.memset.p0i8.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6119 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6120 declare void @llvm.memset.p0i8.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6121 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6122</pre>
6123
6124<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6125<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6126 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6127
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6128<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6129 intrinsic does not return a value, takes extra alignment/volatile arguments,
6130 and the destination can be in an arbitrary address space.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6131
6132<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6133<p>The first argument is a pointer to the destination to fill, the second is the
6134 byte value to fill it with, the third argument is an integer argument
6135 specifying the number of bytes to fill, and the fourth argument is the known
6136 alignment of destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6137
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6138<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]6139 then the caller guarantees that the destination pointer is aligned to that
6140 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6141
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6142<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6143 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6144 The detailed access behavior is not very cleanly specified and it is unwise
6145 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6146
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6147<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6148<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6149 at the destination location. If the argument is known to be aligned to some
6150 boundary, this can be specified as the fourth argument, otherwise it should
6151 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6152
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6153</div>
6154
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6155<!-- _______________________________________________________________________ -->
6156<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6157 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6158</div>
6159
6160<div class="doc_text">
6161
6162<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6163<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6164 floating point or vector of floating point type. Not all targets support all
6165 types however.</p>
6166
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6167<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6168 declare float @llvm.sqrt.f32(float %Val)
6169 declare double @llvm.sqrt.f64(double %Val)
6170 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6171 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6172 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6173</pre>
6174
6175<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6176<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6177 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6178 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6179 behavior for negative numbers other than -0.0 (which allows for better
6180 optimization, because there is no need to worry about errno being
6181 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]6182
6183<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6184<p>The argument and return value are floating point numbers of the same
6185 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6186
6187<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6188<p>This function returns the sqrt of the specified operand if it is a
6189 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6190
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6191</div>
6192
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6193<!-- _______________________________________________________________________ -->
6194<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6195 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6196</div>
6197
6198<div class="doc_text">
6199
6200<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6201<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6202 floating point or vector of floating point type. Not all targets support all
6203 types however.</p>
6204
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6205<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6206 declare float @llvm.powi.f32(float %Val, i32 %power)
6207 declare double @llvm.powi.f64(double %Val, i32 %power)
6208 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6209 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6210 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6211</pre>
6212
6213<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6214<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6215 specified (positive or negative) power. The order of evaluation of
6216 multiplications is not defined. When a vector of floating point type is
6217 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6218
6219<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6220<p>The second argument is an integer power, and the first is a value to raise to
6221 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6222
6223<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6224<p>This function returns the first value raised to the second power with an
6225 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6226
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6227</div>
6228
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6229<!-- _______________________________________________________________________ -->
6230<div class="doc_subsubsection">
6231 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
6232</div>
6233
6234<div class="doc_text">
6235
6236<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6237<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6238 floating point or vector of floating point type. Not all targets support all
6239 types however.</p>
6240
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6241<pre>
6242 declare float @llvm.sin.f32(float %Val)
6243 declare double @llvm.sin.f64(double %Val)
6244 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6245 declare fp128 @llvm.sin.f128(fp128 %Val)
6246 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6247</pre>
6248
6249<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6250<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6251
6252<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6253<p>The argument and return value are floating point numbers of the same
6254 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6255
6256<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6257<p>This function returns the sine of the specified operand, returning the same
6258 values as the libm <tt>sin</tt> functions would, and handles error conditions
6259 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6260
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6261</div>
6262
6263<!-- _______________________________________________________________________ -->
6264<div class="doc_subsubsection">
6265 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
6266</div>
6267
6268<div class="doc_text">
6269
6270<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6271<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6272 floating point or vector of floating point type. Not all targets support all
6273 types however.</p>
6274
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6275<pre>
6276 declare float @llvm.cos.f32(float %Val)
6277 declare double @llvm.cos.f64(double %Val)
6278 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6279 declare fp128 @llvm.cos.f128(fp128 %Val)
6280 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6281</pre>
6282
6283<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6284<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6285
6286<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6287<p>The argument and return value are floating point numbers of the same
6288 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6289
6290<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6291<p>This function returns the cosine of the specified operand, returning the same
6292 values as the libm <tt>cos</tt> functions would, and handles error conditions
6293 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6294
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6295</div>
6296
6297<!-- _______________________________________________________________________ -->
6298<div class="doc_subsubsection">
6299 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
6300</div>
6301
6302<div class="doc_text">
6303
6304<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6305<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6306 floating point or vector of floating point type. Not all targets support all
6307 types however.</p>
6308
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6309<pre>
6310 declare float @llvm.pow.f32(float %Val, float %Power)
6311 declare double @llvm.pow.f64(double %Val, double %Power)
6312 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6313 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6314 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6315</pre>
6316
6317<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6318<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6319 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6320
6321<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6322<p>The second argument is a floating point power, and the first is a value to
6323 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6324
6325<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6326<p>This function returns the first value raised to the second power, returning
6327 the same values as the libm <tt>pow</tt> functions would, and handles error
6328 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6329
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6330</div>
6331
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6332<!-- ======================================================================= -->
6333<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6334 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6335</div>
6336
6337<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6338
6339<p>LLVM provides intrinsics for a few important bit manipulation operations.
6340 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6341
6342</div>
6343
6344<!-- _______________________________________________________________________ -->
6345<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6346 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6347</div>
6348
6349<div class="doc_text">
6350
6351<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6352<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6353 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6354
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6355<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6356 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6357 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6358 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6359</pre>
6360
6361<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6362<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6363 values with an even number of bytes (positive multiple of 16 bits). These
6364 are useful for performing operations on data that is not in the target's
6365 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6366
6367<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6368<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6369 and low byte of the input i16 swapped. Similarly,
6370 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6371 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6372 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6373 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6374 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6375 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6376
6377</div>
6378
6379<!-- _______________________________________________________________________ -->
6380<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]6381 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6382</div>
6383
6384<div class="doc_text">
6385
6386<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6387<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6388 width. Not all targets support all bit widths however.</p>
6389
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6390<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6391 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6392 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6393 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6394 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6395 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6396</pre>
6397
6398<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6399<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6400 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6401
6402<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6403<p>The only argument is the value to be counted. The argument may be of any
6404 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6405
6406<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6407<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6408
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6409</div>
6410
6411<!-- _______________________________________________________________________ -->
6412<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6413 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6414</div>
6415
6416<div class="doc_text">
6417
6418<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6419<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
6420 integer bit width. Not all targets support all bit widths however.</p>
6421
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6422<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6423 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6424 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6425 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6426 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6427 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6428</pre>
6429
6430<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6431<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6432 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6433
6434<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6435<p>The only argument is the value to be counted. The argument may be of any
6436 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6437
6438<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6439<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
6440 zeros in a variable. If the src == 0 then the result is the size in bits of
6441 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6442
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6443</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6444
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6445<!-- _______________________________________________________________________ -->
6446<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6447 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6448</div>
6449
6450<div class="doc_text">
6451
6452<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6453<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
6454 integer bit width. Not all targets support all bit widths however.</p>
6455
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6456<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6457 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6458 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6459 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6460 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6461 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6462</pre>
6463
6464<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6465<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6466 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6467
6468<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6469<p>The only argument is the value to be counted. The argument may be of any
6470 integer type. The return type must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6471
6472<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6473<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
6474 zeros in a variable. If the src == 0 then the result is the size in bits of
6475 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6476
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6477</div>
6478
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6479<!-- ======================================================================= -->
6480<div class="doc_subsection">
6481 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
6482</div>
6483
6484<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6485
6486<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6487
6488</div>
6489
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6490<!-- _______________________________________________________________________ -->
6491<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6492 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6493</div>
6494
6495<div class="doc_text">
6496
6497<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6498<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]6499 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6500
6501<pre>
6502 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6503 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6504 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6505</pre>
6506
6507<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6508<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6509 a signed addition of the two arguments, and indicate whether an overflow
6510 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6511
6512<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6513<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]6514 be of integer types of any bit width, but they must have the same bit
6515 width. The second element of the result structure must be of
6516 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6517 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6518
6519<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6520<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6521 a signed addition of the two variables. They return a structure &mdash; the
6522 first element of which is the signed summation, and the second element of
6523 which is a bit specifying if the signed summation resulted in an
6524 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6525
6526<h5>Examples:</h5>
6527<pre>
6528 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6529 %sum = extractvalue {i32, i1} %res, 0
6530 %obit = extractvalue {i32, i1} %res, 1
6531 br i1 %obit, label %overflow, label %normal
6532</pre>
6533
6534</div>
6535
6536<!-- _______________________________________________________________________ -->
6537<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6538 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6539</div>
6540
6541<div class="doc_text">
6542
6543<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6544<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]6545 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6546
6547<pre>
6548 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6549 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6550 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6551</pre>
6552
6553<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6554<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6555 an unsigned addition of the two arguments, and indicate whether a carry
6556 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6557
6558<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6559<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]6560 be of integer types of any bit width, but they must have the same bit
6561 width. The second element of the result structure must be of
6562 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6563 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6564
6565<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6566<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6567 an unsigned addition of the two arguments. They return a structure &mdash;
6568 the first element of which is the sum, and the second element of which is a
6569 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6570
6571<h5>Examples:</h5>
6572<pre>
6573 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6574 %sum = extractvalue {i32, i1} %res, 0
6575 %obit = extractvalue {i32, i1} %res, 1
6576 br i1 %obit, label %carry, label %normal
6577</pre>
6578
6579</div>
6580
6581<!-- _______________________________________________________________________ -->
6582<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6583 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6584</div>
6585
6586<div class="doc_text">
6587
6588<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6589<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]6590 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6591
6592<pre>
6593 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6594 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6595 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6596</pre>
6597
6598<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6599<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6600 a signed subtraction of the two arguments, and indicate whether an overflow
6601 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6602
6603<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6604<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]6605 be of integer types of any bit width, but they must have the same bit
6606 width. The second element of the result structure must be of
6607 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6608 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6609
6610<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6611<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6612 a signed subtraction of the two arguments. They return a structure &mdash;
6613 the first element of which is the subtraction, and the second element of
6614 which is a bit specifying if the signed subtraction resulted in an
6615 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6616
6617<h5>Examples:</h5>
6618<pre>
6619 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6620 %sum = extractvalue {i32, i1} %res, 0
6621 %obit = extractvalue {i32, i1} %res, 1
6622 br i1 %obit, label %overflow, label %normal
6623</pre>
6624
6625</div>
6626
6627<!-- _______________________________________________________________________ -->
6628<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6629 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6630</div>
6631
6632<div class="doc_text">
6633
6634<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6635<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]6636 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6637
6638<pre>
6639 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6640 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6641 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6642</pre>
6643
6644<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6645<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6646 an unsigned subtraction of the two arguments, and indicate whether an
6647 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6648
6649<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6650<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]6651 be of integer types of any bit width, but they must have the same bit
6652 width. The second element of the result structure must be of
6653 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6654 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6655
6656<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6657<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6658 an unsigned subtraction of the two arguments. They return a structure &mdash;
6659 the first element of which is the subtraction, and the second element of
6660 which is a bit specifying if the unsigned subtraction resulted in an
6661 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6662
6663<h5>Examples:</h5>
6664<pre>
6665 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6666 %sum = extractvalue {i32, i1} %res, 0
6667 %obit = extractvalue {i32, i1} %res, 1
6668 br i1 %obit, label %overflow, label %normal
6669</pre>
6670
6671</div>
6672
6673<!-- _______________________________________________________________________ -->
6674<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6675 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6676</div>
6677
6678<div class="doc_text">
6679
6680<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6681<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]6682 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6683
6684<pre>
6685 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6686 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6687 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6688</pre>
6689
6690<h5>Overview:</h5>
6691
6692<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6693 a signed multiplication of the two arguments, and indicate whether an
6694 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6695
6696<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6697<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]6698 be of integer types of any bit width, but they must have the same bit
6699 width. The second element of the result structure must be of
6700 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6701 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6702
6703<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6704<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6705 a signed multiplication of the two arguments. They return a structure &mdash;
6706 the first element of which is the multiplication, and the second element of
6707 which is a bit specifying if the signed multiplication resulted in an
6708 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6709
6710<h5>Examples:</h5>
6711<pre>
6712 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6713 %sum = extractvalue {i32, i1} %res, 0
6714 %obit = extractvalue {i32, i1} %res, 1
6715 br i1 %obit, label %overflow, label %normal
6716</pre>
6717
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6718</div>
6719
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6720<!-- _______________________________________________________________________ -->
6721<div class="doc_subsubsection">
6722 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6723</div>
6724
6725<div class="doc_text">
6726
6727<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6728<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]6729 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6730
6731<pre>
6732 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6733 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6734 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6735</pre>
6736
6737<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6738<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6739 a unsigned multiplication of the two arguments, and indicate whether an
6740 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6741
6742<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6743<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]6744 be of integer types of any bit width, but they must have the same bit
6745 width. The second element of the result structure must be of
6746 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6747 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6748
6749<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6750<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6751 an unsigned multiplication of the two arguments. They return a structure
6752 &mdash; the first element of which is the multiplication, and the second
6753 element of which is a bit specifying if the unsigned multiplication resulted
6754 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6755
6756<h5>Examples:</h5>
6757<pre>
6758 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6759 %sum = extractvalue {i32, i1} %res, 0
6760 %obit = extractvalue {i32, i1} %res, 1
6761 br i1 %obit, label %overflow, label %normal
6762</pre>
6763
6764</div>
6765
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6766<!-- ======================================================================= -->
6767<div class="doc_subsection">
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6768 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
6769</div>
6770
6771<div class="doc_text">
6772
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6773<p>Half precision floating point is a storage-only format. This means that it is
6774 a dense encoding (in memory) but does not support computation in the
6775 format.</p>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6776
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6777<p>This means that code must first load the half-precision floating point
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6778 value as an i16, then convert it to float with <a
6779 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
6780 Computation can then be performed on the float value (including extending to
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6781 double etc). To store the value back to memory, it is first converted to
6782 float if needed, then converted to i16 with
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6783 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
6784 storing as an i16 value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6785</div>
6786
6787<!-- _______________________________________________________________________ -->
6788<div class="doc_subsubsection">
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6789 <a name="int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6790</div>
6791
6792<div class="doc_text">
6793
6794<h5>Syntax:</h5>
6795<pre>
6796 declare i16 @llvm.convert.to.fp16(f32 %a)
6797</pre>
6798
6799<h5>Overview:</h5>
6800<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
6801 a conversion from single precision floating point format to half precision
6802 floating point format.</p>
6803
6804<h5>Arguments:</h5>
6805<p>The intrinsic function contains single argument - the value to be
6806 converted.</p>
6807
6808<h5>Semantics:</h5>
6809<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
6810 a conversion from single precision floating point format to half precision
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6811 floating point format. The return value is an <tt>i16</tt> which
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6812 contains the converted number.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6813
6814<h5>Examples:</h5>
6815<pre>
6816 %res = call i16 @llvm.convert.to.fp16(f32 %a)
6817 store i16 %res, i16* @x, align 2
6818</pre>
6819
6820</div>
6821
6822<!-- _______________________________________________________________________ -->
6823<div class="doc_subsubsection">
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6824 <a name="int_convert_from_fp16">'<tt>llvm.convert.from.fp16</tt>' Intrinsic</a>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6825</div>
6826
6827<div class="doc_text">
6828
6829<h5>Syntax:</h5>
6830<pre>
6831 declare f32 @llvm.convert.from.fp16(i16 %a)
6832</pre>
6833
6834<h5>Overview:</h5>
6835<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
6836 a conversion from half precision floating point format to single precision
6837 floating point format.</p>
6838
6839<h5>Arguments:</h5>
6840<p>The intrinsic function contains single argument - the value to be
6841 converted.</p>
6842
6843<h5>Semantics:</h5>
6844<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6845 conversion from half single precision floating point format to single
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6846 precision floating point format. The input half-float value is represented by
6847 an <tt>i16</tt> value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6848
6849<h5>Examples:</h5>
6850<pre>
6851 %a = load i16* @x, align 2
6852 %res = call f32 @llvm.convert.from.fp16(i16 %a)
6853</pre>
6854
6855</div>
6856
6857<!-- ======================================================================= -->
6858<div class="doc_subsection">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6859 <a name="int_debugger">Debugger Intrinsics</a>
6860</div>
6861
6862<div class="doc_text">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6863
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6864<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6865 prefix), are described in
6866 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6867 Level Debugging</a> document.</p>
6868
6869</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6870
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6871<!-- ======================================================================= -->
6872<div class="doc_subsection">
6873 <a name="int_eh">Exception Handling Intrinsics</a>
6874</div>
6875
6876<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6877
6878<p>The LLVM exception handling intrinsics (which all start with
6879 <tt>llvm.eh.</tt> prefix), are described in
6880 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6881 Handling</a> document.</p>
6882
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6883</div>
6884
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6885<!-- ======================================================================= -->
6886<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6887 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6888</div>
6889
6890<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6891
6892<p>This intrinsic makes it possible to excise one parameter, marked with
6893 the <tt>nest</tt> attribute, from a function. The result is a callable
6894 function pointer lacking the nest parameter - the caller does not need to
6895 provide a value for it. Instead, the value to use is stored in advance in a
6896 "trampoline", a block of memory usually allocated on the stack, which also
6897 contains code to splice the nest value into the argument list. This is used
6898 to implement the GCC nested function address extension.</p>
6899
6900<p>For example, if the function is
6901 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6902 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6903 follows:</p>
6904
6905<div class="doc_code">
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6906<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6907 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6908 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6909 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6910 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6911</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6912</div>
6913
6914<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6915 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6916
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6917</div>
6918
6919<!-- _______________________________________________________________________ -->
6920<div class="doc_subsubsection">
6921 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6922</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6923
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6924<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6925
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6926<h5>Syntax:</h5>
6927<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6928 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]6929</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6930
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6931<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6932<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6933 function pointer suitable for executing it.</p>
6934
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6935<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6936<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6937 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6938 sufficiently aligned block of memory; this memory is written to by the
6939 intrinsic. Note that the size and the alignment are target-specific - LLVM
6940 currently provides no portable way of determining them, so a front-end that
6941 generates this intrinsic needs to have some target-specific knowledge.
6942 The <tt>func</tt> argument must hold a function bitcast to
6943 an <tt>i8*</tt>.</p>
6944
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6945<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6946<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6947 dependent code, turning it into a function. A pointer to this function is
6948 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6949 function pointer type</a> before being called. The new function's signature
6950 is the same as that of <tt>func</tt> with any arguments marked with
6951 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6952 is allowed, and it must be of pointer type. Calling the new function is
6953 equivalent to calling <tt>func</tt> with the same argument list, but
6954 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6955 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6956 by <tt>tramp</tt> is modified, then the effect of any later call to the
6957 returned function pointer is undefined.</p>
6958
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6959</div>
6960
6961<!-- ======================================================================= -->
6962<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6963 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6964</div>
6965
6966<div class="doc_text">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6967
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6968<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6969 hardware constructs for atomic operations and memory synchronization. This
6970 provides an interface to the hardware, not an interface to the programmer. It
6971 is aimed at a low enough level to allow any programming models or APIs
6972 (Application Programming Interfaces) which need atomic behaviors to map
6973 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6974 hardware provides a "universal IR" for source languages, it also provides a
6975 starting point for developing a "universal" atomic operation and
6976 synchronization IR.</p>
6977
6978<p>These do <em>not</em> form an API such as high-level threading libraries,
6979 software transaction memory systems, atomic primitives, and intrinsic
6980 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6981 application libraries. The hardware interface provided by LLVM should allow
6982 a clean implementation of all of these APIs and parallel programming models.
6983 No one model or paradigm should be selected above others unless the hardware
6984 itself ubiquitously does so.</p>
6985
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6986</div>
6987
6988<!-- _______________________________________________________________________ -->
6989<div class="doc_subsubsection">
6990 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6991</div>
6992<div class="doc_text">
6993<h5>Syntax:</h5>
6994<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6995 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]6996</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6997
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6998<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6999<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7000 specific pairs of memory access types.</p>
7001
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7002<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7003<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7004 The first four arguments enables a specific barrier as listed below. The
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]7005 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7006 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7007
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7008<ul>
7009 <li><tt>ll</tt>: load-load barrier</li>
7010 <li><tt>ls</tt>: load-store barrier</li>
7011 <li><tt>sl</tt>: store-load barrier</li>
7012 <li><tt>ss</tt>: store-store barrier</li>
7013 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7014</ul>
7015
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7016<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7017<p>This intrinsic causes the system to enforce some ordering constraints upon
7018 the loads and stores of the program. This barrier does not
7019 indicate <em>when</em> any events will occur, it only enforces
7020 an <em>order</em> in which they occur. For any of the specified pairs of load
7021 and store operations (f.ex. load-load, or store-load), all of the first
7022 operations preceding the barrier will complete before any of the second
7023 operations succeeding the barrier begin. Specifically the semantics for each
7024 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7025
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7026<ul>
7027 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7028 after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7029 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7030 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7031 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7032 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7033 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7034 load after the barrier begins.</li>
7035</ul>
7036
7037<p>These semantics are applied with a logical "and" behavior when more than one
7038 is enabled in a single memory barrier intrinsic.</p>
7039
7040<p>Backends may implement stronger barriers than those requested when they do
7041 not support as fine grained a barrier as requested. Some architectures do
7042 not need all types of barriers and on such architectures, these become
7043 noops.</p>
7044
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7045<h5>Example:</h5>
7046<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7047%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7048%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7049 store i32 4, %ptr
7050
7051%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
7052 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
7053 <i>; guarantee the above finishes</i>
7054 store i32 8, %ptr <i>; before this begins</i>
7055</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7056
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7057</div>
7058
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7059<!-- _______________________________________________________________________ -->
7060<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7061 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7062</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7063
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7064<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7065
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7066<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7067<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7068 any integer bit width and for different address spaces. Not all targets
7069 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7070
7071<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7072 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
7073 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
7074 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
7075 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]7076</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7077
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7078<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7079<p>This loads a value in memory and compares it to a given value. If they are
7080 equal, it stores a new value into the memory.</p>
7081
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7082<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7083<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7084 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7085 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7086 this integer type. While any bit width integer may be used, targets may only
7087 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7088
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7089<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7090<p>This entire intrinsic must be executed atomically. It first loads the value
7091 in memory pointed to by <tt>ptr</tt> and compares it with the
7092 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7093 memory. The loaded value is yielded in all cases. This provides the
7094 equivalent of an atomic compare-and-swap operation within the SSA
7095 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7096
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7097<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7098<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7099%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7100%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7101 store i32 4, %ptr
7102
7103%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7104%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7105 <i>; yields {i32}:result1 = 4</i>
7106%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7107%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7108
7109%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7110%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7111 <i>; yields {i32}:result2 = 8</i>
7112%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7113
7114%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7115</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7116
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7117</div>
7118
7119<!-- _______________________________________________________________________ -->
7120<div class="doc_subsubsection">
7121 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
7122</div>
7123<div class="doc_text">
7124<h5>Syntax:</h5>
7125
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7126<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7127 integer bit width. Not all targets support all bit widths however.</p>
7128
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7129<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7130 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
7131 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
7132 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
7133 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]7134</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7135
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7136<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7137<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7138 the value from memory. It then stores the value in <tt>val</tt> in the memory
7139 at <tt>ptr</tt>.</p>
7140
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7141<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7142<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7143 the <tt>val</tt> argument and the result must be integers of the same bit
7144 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7145 integer type. The targets may only lower integer representations they
7146 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7147
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7148<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7149<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7150 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7151 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7152
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7153<h5>Examples:</h5>
7154<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7155%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7156%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7157 store i32 4, %ptr
7158
7159%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7160%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7161 <i>; yields {i32}:result1 = 4</i>
7162%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7163%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7164
7165%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7166%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7167 <i>; yields {i32}:result2 = 8</i>
7168
7169%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7170%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7171</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7172
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7173</div>
7174
7175<!-- _______________________________________________________________________ -->
7176<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7177 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7178
7179</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7180
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7181<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7182
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7183<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7184<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7185 any integer bit width. Not all targets support all bit widths however.</p>
7186
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7187<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7188 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7189 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7190 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7191 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]7192</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7193
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7194<h5>Overview:</h5>
7195<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7196 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7197
7198<h5>Arguments:</h5>
7199<p>The intrinsic takes two arguments, the first a pointer to an integer value
7200 and the second an integer value. The result is also an integer value. These
7201 integer types can have any bit width, but they must all have the same bit
7202 width. The targets may only lower integer representations they support.</p>
7203
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7204<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7205<p>This intrinsic does a series of operations atomically. It first loads the
7206 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7207 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]7208
7209<h5>Examples:</h5>
7210<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7211%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7212%ptr = bitcast i8* %mallocP to i32*
7213 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7214%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7215 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7216%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7217 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7218%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7219 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7220%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7221</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7222
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7223</div>
7224
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7225<!-- _______________________________________________________________________ -->
7226<div class="doc_subsubsection">
7227 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
7228
7229</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7230
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7231<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7232
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7233<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7234<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7235 any integer bit width and for different address spaces. Not all targets
7236 support all bit widths however.</p>
7237
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7238<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7239 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7240 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7241 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7242 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]7243</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7244
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7245<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7246<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7247 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7248
7249<h5>Arguments:</h5>
7250<p>The intrinsic takes two arguments, the first a pointer to an integer value
7251 and the second an integer value. The result is also an integer value. These
7252 integer types can have any bit width, but they must all have the same bit
7253 width. The targets may only lower integer representations they support.</p>
7254
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7255<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7256<p>This intrinsic does a series of operations atomically. It first loads the
7257 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7258 result to <tt>ptr</tt>. It yields the original value stored
7259 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7260
7261<h5>Examples:</h5>
7262<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7263%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7264%ptr = bitcast i8* %mallocP to i32*
7265 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7266%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7267 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7268%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7269 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7270%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7271 <i>; yields {i32}:result3 = 2</i>
7272%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7273</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7274
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7275</div>
7276
7277<!-- _______________________________________________________________________ -->
7278<div class="doc_subsubsection">
7279 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
7280 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
7281 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
7282 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7283</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7284
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7285<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7286
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7287<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7288<p>These are overloaded intrinsics. You can
7289 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7290 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7291 bit width and for different address spaces. Not all targets support all bit
7292 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7293
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7294<pre>
7295 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7296 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7297 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7298 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]7299</pre>
7300
7301<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7302 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7303 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7304 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7305 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]7306</pre>
7307
7308<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7309 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7310 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7311 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7312 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]7313</pre>
7314
7315<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7316 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7317 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7318 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7319 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]7320</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7321
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7322<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7323<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7324 the value stored in memory at <tt>ptr</tt>. It yields the original value
7325 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7326
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7327<h5>Arguments:</h5>
7328<p>These intrinsics take two arguments, the first a pointer to an integer value
7329 and the second an integer value. The result is also an integer value. These
7330 integer types can have any bit width, but they must all have the same bit
7331 width. The targets may only lower integer representations they support.</p>
7332
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7333<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7334<p>These intrinsics does a series of operations atomically. They first load the
7335 value stored at <tt>ptr</tt>. They then do the bitwise
7336 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7337 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7338
7339<h5>Examples:</h5>
7340<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7341%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7342%ptr = bitcast i8* %mallocP to i32*
7343 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7344%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7345 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7346%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7347 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7348%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7349 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7350%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7351 <i>; yields {i32}:result3 = FF</i>
7352%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7353</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7354
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7355</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7356
7357<!-- _______________________________________________________________________ -->
7358<div class="doc_subsubsection">
7359 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
7360 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
7361 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
7362 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7363</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7364
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7365<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7366
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7367<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7368<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7369 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7370 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7371 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7372
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7373<pre>
7374 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7375 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7376 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7377 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]7378</pre>
7379
7380<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7381 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7382 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7383 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7384 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]7385</pre>
7386
7387<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7388 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7389 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7390 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7391 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]7392</pre>
7393
7394<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7395 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7396 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7397 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7398 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]7399</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7400
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7401<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7402<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7403 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7404 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7405
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7406<h5>Arguments:</h5>
7407<p>These intrinsics take two arguments, the first a pointer to an integer value
7408 and the second an integer value. The result is also an integer value. These
7409 integer types can have any bit width, but they must all have the same bit
7410 width. The targets may only lower integer representations they support.</p>
7411
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7412<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7413<p>These intrinsics does a series of operations atomically. They first load the
7414 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7415 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7416 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7417
7418<h5>Examples:</h5>
7419<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7420%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7421%ptr = bitcast i8* %mallocP to i32*
7422 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7423%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7424 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7425%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7426 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7427%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7428 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7429%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7430 <i>; yields {i32}:result3 = 8</i>
7431%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7432</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7433
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7434</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7435
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7436
7437<!-- ======================================================================= -->
7438<div class="doc_subsection">
7439 <a name="int_memorymarkers">Memory Use Markers</a>
7440</div>
7441
7442<div class="doc_text">
7443
7444<p>This class of intrinsics exists to information about the lifetime of memory
7445 objects and ranges where variables are immutable.</p>
7446
7447</div>
7448
7449<!-- _______________________________________________________________________ -->
7450<div class="doc_subsubsection">
7451 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
7452</div>
7453
7454<div class="doc_text">
7455
7456<h5>Syntax:</h5>
7457<pre>
7458 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7459</pre>
7460
7461<h5>Overview:</h5>
7462<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7463 object's lifetime.</p>
7464
7465<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7466<p>The first argument is a constant integer representing the size of the
7467 object, or -1 if it is variable sized. The second argument is a pointer to
7468 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7469
7470<h5>Semantics:</h5>
7471<p>This intrinsic indicates that before this point in the code, the value of the
7472 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]7473 never be used and has an undefined value. A load from the pointer that
7474 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7475 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7476
7477</div>
7478
7479<!-- _______________________________________________________________________ -->
7480<div class="doc_subsubsection">
7481 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
7482</div>
7483
7484<div class="doc_text">
7485
7486<h5>Syntax:</h5>
7487<pre>
7488 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7489</pre>
7490
7491<h5>Overview:</h5>
7492<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7493 object's lifetime.</p>
7494
7495<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7496<p>The first argument is a constant integer representing the size of the
7497 object, or -1 if it is variable sized. The second argument is a pointer to
7498 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7499
7500<h5>Semantics:</h5>
7501<p>This intrinsic indicates that after this point in the code, the value of the
7502 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7503 never be used and has an undefined value. Any stores into the memory object
7504 following this intrinsic may be removed as dead.
7505
7506</div>
7507
7508<!-- _______________________________________________________________________ -->
7509<div class="doc_subsubsection">
7510 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
7511</div>
7512
7513<div class="doc_text">
7514
7515<h5>Syntax:</h5>
7516<pre>
7517 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;) readonly
7518</pre>
7519
7520<h5>Overview:</h5>
7521<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7522 a memory object will not change.</p>
7523
7524<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7525<p>The first argument is a constant integer representing the size of the
7526 object, or -1 if it is variable sized. The second argument is a pointer to
7527 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7528
7529<h5>Semantics:</h5>
7530<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7531 the return value, the referenced memory location is constant and
7532 unchanging.</p>
7533
7534</div>
7535
7536<!-- _______________________________________________________________________ -->
7537<div class="doc_subsubsection">
7538 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
7539</div>
7540
7541<div class="doc_text">
7542
7543<h5>Syntax:</h5>
7544<pre>
7545 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7546</pre>
7547
7548<h5>Overview:</h5>
7549<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7550 a memory object are mutable.</p>
7551
7552<h5>Arguments:</h5>
7553<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7554 The second argument is a constant integer representing the size of the
7555 object, or -1 if it is variable sized and the third argument is a pointer
7556 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7557
7558<h5>Semantics:</h5>
7559<p>This intrinsic indicates that the memory is mutable again.</p>
7560
7561</div>
7562
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7563<!-- ======================================================================= -->
7564<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7565 <a name="int_general">General Intrinsics</a>
7566</div>
7567
7568<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7569
7570<p>This class of intrinsics is designed to be generic and has no specific
7571 purpose.</p>
7572
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7573</div>
7574
7575<!-- _______________________________________________________________________ -->
7576<div class="doc_subsubsection">
7577 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
7578</div>
7579
7580<div class="doc_text">
7581
7582<h5>Syntax:</h5>
7583<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]7584 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]7585</pre>
7586
7587<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7588<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7589
7590<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7591<p>The first argument is a pointer to a value, the second is a pointer to a
7592 global string, the third is a pointer to a global string which is the source
7593 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7594
7595<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7596<p>This intrinsic allows annotation of local variables with arbitrary strings.
7597 This can be useful for special purpose optimizations that want to look for
7598 these annotations. These have no other defined use, they are ignored by code
7599 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7600
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7601</div>
7602
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7603<!-- _______________________________________________________________________ -->
7604<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]7605 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7606</div>
7607
7608<div class="doc_text">
7609
7610<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7611<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7612 any integer bit width.</p>
7613
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7614<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]7615 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7616 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7617 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7618 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7619 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]7620</pre>
7621
7622<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7623<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7624
7625<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7626<p>The first argument is an integer value (result of some expression), the
7627 second is a pointer to a global string, the third is a pointer to a global
7628 string which is the source file name, and the last argument is the line
7629 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7630
7631<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7632<p>This intrinsic allows annotations to be put on arbitrary expressions with
7633 arbitrary strings. This can be useful for special purpose optimizations that
7634 want to look for these annotations. These have no other defined use, they
7635 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7636
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7637</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7638
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7639<!-- _______________________________________________________________________ -->
7640<div class="doc_subsubsection">
7641 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
7642</div>
7643
7644<div class="doc_text">
7645
7646<h5>Syntax:</h5>
7647<pre>
7648 declare void @llvm.trap()
7649</pre>
7650
7651<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7652<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7653
7654<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7655<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7656
7657<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7658<p>This intrinsics is lowered to the target dependent trap instruction. If the
7659 target does not have a trap instruction, this intrinsic will be lowered to
7660 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7661
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7662</div>
7663
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7664<!-- _______________________________________________________________________ -->
7665<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]7666 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7667</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7668
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7669<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7670
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7671<h5>Syntax:</h5>
7672<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7673 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7674</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7675
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7676<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7677<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7678 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7679 ensure that it is placed on the stack before local variables.</p>
7680
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7681<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7682<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7683 arguments. The first argument is the value loaded from the stack
7684 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7685 that has enough space to hold the value of the guard.</p>
7686
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7687<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7688<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7689 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7690 stack. This is to ensure that if a local variable on the stack is
7691 overwritten, it will destroy the value of the guard. When the function exits,
7692 the guard on the stack is checked against the original guard. If they're
7693 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7694 function.</p>
7695
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7696</div>
7697
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7698<!-- _______________________________________________________________________ -->
7699<div class="doc_subsubsection">
7700 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
7701</div>
7702
7703<div class="doc_text">
7704
7705<h5>Syntax:</h5>
7706<pre>
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7707 declare i32 @llvm.objectsize.i32( i8* &lt;object&gt;, i1 &lt;type&gt; )
7708 declare i64 @llvm.objectsize.i64( i8* &lt;object&gt;, i1 &lt;type&gt; )
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7709</pre>
7710
7711<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7712<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information
Eric Christopherd003c5b2010-01-08 21:42:39 +0000[diff] [blame]7713 to the optimizers to discover at compile time either a) when an
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7714 operation like memcpy will either overflow a buffer that corresponds to
7715 an object, or b) to determine that a runtime check for overflow isn't
7716 necessary. An object in this context means an allocation of a
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7717 specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7718
7719<h5>Arguments:</h5>
7720<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7721 argument is a pointer to or into the <tt>object</tt>. The second argument
7722 is a boolean 0 or 1. This argument determines whether you want the
7723 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
7724 1, variables are not allowed.</p>
7725
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7726<h5>Semantics:</h5>
7727<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7728 representing the size of the object concerned or <tt>i32/i64 -1 or 0</tt>
7729 (depending on the <tt>type</tt> argument if the size cannot be determined
7730 at compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7731
7732</div>
7733
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7734<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7735<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7736<address>
7737 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]7738 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7739 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]7740 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7741
7742 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]7743 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7744 Last modified: $Date$
7745</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]7746
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]7747</body>
7748</html>