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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / c30f6e1c89e5a046ab9a58b08248cbb3c796529c / . / 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>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]53 </ol>
54 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]55 <li><a href="#typesystem">Type System</a>
56 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]57 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]58 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]59 <ol>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]60 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]61 <li><a href="#t_floating">Floating Point Types</a></li>
62 <li><a href="#t_void">Void Type</a></li>
63 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]64 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]65 </ol>
66 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]67 <li><a href="#t_derived">Derived Types</a>
68 <ol>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]69 <li><a href="#t_aggregate">Aggregate Types</a>
70 <ol>
71 <li><a href="#t_array">Array Type</a></li>
72 <li><a href="#t_struct">Structure Type</a></li>
73 <li><a href="#t_pstruct">Packed Structure Type</a></li>
74 <li><a href="#t_union">Union Type</a></li>
75 <li><a href="#t_vector">Vector Type</a></li>
76 </ol>
77 </li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]78 <li><a href="#t_function">Function Type</a></li>
79 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]80 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]81 </ol>
82 </li>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]83 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]84 </ol>
85 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]86 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]87 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]88 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]89 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]90 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
91 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]92 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]93 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]94 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]95 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]96 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]97 <li><a href="#othervalues">Other Values</a>
98 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]99 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]100 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]101 </ol>
102 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]103 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
104 <ol>
105 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]106 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
107 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]108 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
109 Global Variable</a></li>
110 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
111 Global Variable</a></li>
112 </ol>
113 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]114 <li><a href="#instref">Instruction Reference</a>
115 <ol>
116 <li><a href="#terminators">Terminator Instructions</a>
117 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]118 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
119 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]120 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]121 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]122 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]123 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]124 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]125 </ol>
126 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]127 <li><a href="#binaryops">Binary Operations</a>
128 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]129 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]130 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]131 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]132 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]133 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]134 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]135 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
136 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
137 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]138 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
139 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
140 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]141 </ol>
142 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]143 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
144 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]145 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
146 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
147 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]148 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]149 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]150 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]151 </ol>
152 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]153 <li><a href="#vectorops">Vector Operations</a>
154 <ol>
155 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
156 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
157 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]158 </ol>
159 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]160 <li><a href="#aggregateops">Aggregate Operations</a>
161 <ol>
162 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
163 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
164 </ol>
165 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]166 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]167 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]168 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]169 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
170 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
171 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]172 </ol>
173 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]174 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]175 <ol>
176 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
177 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
178 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
179 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
180 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]181 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
182 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
183 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
184 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]185 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
186 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]187 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]188 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]189 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]190 <li><a href="#otherops">Other Operations</a>
191 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]192 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
193 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]194 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]195 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]196 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]197 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]198 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]199 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]200 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]201 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]202 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]203 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]204 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
205 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]206 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
207 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
208 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]209 </ol>
210 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]211 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
212 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]213 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
214 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
215 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]216 </ol>
217 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]218 <li><a href="#int_codegen">Code Generator Intrinsics</a>
219 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]220 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
221 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
222 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
223 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
224 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
225 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
226 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]227 </ol>
228 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]229 <li><a href="#int_libc">Standard C Library Intrinsics</a>
230 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]231 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
232 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
233 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
234 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
235 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]236 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
237 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
238 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]239 </ol>
240 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]241 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]242 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]243 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]244 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
245 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
246 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]247 </ol>
248 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]249 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
250 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]251 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
252 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
253 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
254 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
255 <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]256 <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]257 </ol>
258 </li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]259 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
260 <ol>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]261 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
262 <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]263 </ol>
264 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]265 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]266 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]267 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]268 <ol>
269 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]270 </ol>
271 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]272 <li><a href="#int_atomics">Atomic intrinsics</a>
273 <ol>
274 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
275 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
276 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
277 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
278 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
279 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
280 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
281 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
282 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
283 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
284 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
285 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
286 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
287 </ol>
288 </li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]289 <li><a href="#int_memorymarkers">Memory Use Markers</a>
290 <ol>
291 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
292 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
293 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
294 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
295 </ol>
296 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]297 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]298 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]299 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]300 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]301 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]302 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]303 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]304 '<tt>llvm.trap</tt>' Intrinsic</a></li>
305 <li><a href="#int_stackprotector">
306 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]307 <li><a href="#int_objectsize">
308 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]309 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]310 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]311 </ol>
312 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]313</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]314
315<div class="doc_author">
316 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
317 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]318</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]319
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]320<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]321<div class="doc_section"> <a name="abstract">Abstract </a></div>
322<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]323
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]324<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]325
326<p>This document is a reference manual for the LLVM assembly language. LLVM is
327 a Static Single Assignment (SSA) based representation that provides type
328 safety, low-level operations, flexibility, and the capability of representing
329 'all' high-level languages cleanly. It is the common code representation
330 used throughout all phases of the LLVM compilation strategy.</p>
331
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]332</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]333
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]334<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]335<div class="doc_section"> <a name="introduction">Introduction</a> </div>
336<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]337
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]338<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]339
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]340<p>The LLVM code representation is designed to be used in three different forms:
341 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
342 for fast loading by a Just-In-Time compiler), and as a human readable
343 assembly language representation. This allows LLVM to provide a powerful
344 intermediate representation for efficient compiler transformations and
345 analysis, while providing a natural means to debug and visualize the
346 transformations. The three different forms of LLVM are all equivalent. This
347 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]348
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]349<p>The LLVM representation aims to be light-weight and low-level while being
350 expressive, typed, and extensible at the same time. It aims to be a
351 "universal IR" of sorts, by being at a low enough level that high-level ideas
352 may be cleanly mapped to it (similar to how microprocessors are "universal
353 IR's", allowing many source languages to be mapped to them). By providing
354 type information, LLVM can be used as the target of optimizations: for
355 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]356 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]357 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]358
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]359</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]360
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]361<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]362<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]363
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]364<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]365
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]366<p>It is important to note that this document describes 'well formed' LLVM
367 assembly language. There is a difference between what the parser accepts and
368 what is considered 'well formed'. For example, the following instruction is
369 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]370
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]371<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]372<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]373%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]374</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]375</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]376
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]377<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
378 LLVM infrastructure provides a verification pass that may be used to verify
379 that an LLVM module is well formed. This pass is automatically run by the
380 parser after parsing input assembly and by the optimizer before it outputs
381 bitcode. The violations pointed out by the verifier pass indicate bugs in
382 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]383
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]384</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]385
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]386<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]387
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]388<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]389<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]390<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]391
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]392<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]393
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]394<p>LLVM identifiers come in two basic types: global and local. Global
395 identifiers (functions, global variables) begin with the <tt>'@'</tt>
396 character. Local identifiers (register names, types) begin with
397 the <tt>'%'</tt> character. Additionally, there are three different formats
398 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]399
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]400<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]401 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]402 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
403 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
404 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
405 other characters in their names can be surrounded with quotes. Special
406 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
407 ASCII code for the character in hexadecimal. In this way, any character
408 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]409
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]410 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]411 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]412
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]413 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]414 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]415</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]416
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]417<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]418 don't need to worry about name clashes with reserved words, and the set of
419 reserved words may be expanded in the future without penalty. Additionally,
420 unnamed identifiers allow a compiler to quickly come up with a temporary
421 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]422
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]423<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]424 languages. There are keywords for different opcodes
425 ('<tt><a href="#i_add">add</a></tt>',
426 '<tt><a href="#i_bitcast">bitcast</a></tt>',
427 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
428 ('<tt><a href="#t_void">void</a></tt>',
429 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
430 reserved words cannot conflict with variable names, because none of them
431 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]432
433<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]434 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]435
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]436<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]437
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]438<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]439<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]440%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]441</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]442</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]443
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]444<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]445
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]446<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]447<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]448%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]449</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]450</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]451
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]452<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]453
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]454<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]455<pre>
Gabor Greifec58f752009-10-28 13:05:07 +0000[diff] [blame]456%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
457%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]458%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]459</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]460</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]461
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]462<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
463 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]464
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]465<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]466 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]467 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]468
469 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]470 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]471
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]472 <li>Unnamed temporaries are numbered sequentially</li>
473</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]474
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]475<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]476 demonstrating instructions, we will follow an instruction with a comment that
477 defines the type and name of value produced. Comments are shown in italic
478 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]479
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]480</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]481
482<!-- *********************************************************************** -->
483<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
484<!-- *********************************************************************** -->
485
486<!-- ======================================================================= -->
487<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
488</div>
489
490<div class="doc_text">
491
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]492<p>LLVM programs are composed of "Module"s, each of which is a translation unit
493 of the input programs. Each module consists of functions, global variables,
494 and symbol table entries. Modules may be combined together with the LLVM
495 linker, which merges function (and global variable) definitions, resolves
496 forward declarations, and merges symbol table entries. Here is an example of
497 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]498
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]499<div class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]500<pre>
501<i>; Declare the string constant as a global constant.</i>
502<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]503
504<i>; External declaration of the puts function</i>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]505<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]506
507<i>; Definition of main function</i>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]508define i32 @main() { <i>; i32()* </i>
509 <i>; Convert [13 x i8]* to i8 *...</i>
510 %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]511
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]512 <i>; Call puts function to write out the string to stdout.</i>
513 <a href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]514 <a href="#i_ret">ret</a> i32 0<br>}
515
516<i>; Named metadata</i>
517!1 = metadata !{i32 41}
518!foo = !{!1, null}
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]519</pre>
520</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]521
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]522<p>This example is made up of a <a href="#globalvars">global variable</a> named
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]523 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]524 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]525 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
526 "<tt>foo"</tt>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]527
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]528<p>In general, a module is made up of a list of global values, where both
529 functions and global variables are global values. Global values are
530 represented by a pointer to a memory location (in this case, a pointer to an
531 array of char, and a pointer to a function), and have one of the
532 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]533
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]534</div>
535
536<!-- ======================================================================= -->
537<div class="doc_subsection">
538 <a name="linkage">Linkage Types</a>
539</div>
540
541<div class="doc_text">
542
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]543<p>All Global Variables and Functions have one of the following types of
544 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]545
546<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]547 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]548 <dd>Global values with private linkage are only directly accessible by objects
549 in the current module. In particular, linking code into a module with an
550 private global value may cause the private to be renamed as necessary to
551 avoid collisions. Because the symbol is private to the module, all
552 references can be updated. This doesn't show up in any symbol table in the
553 object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]554
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]555 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]556 <dd>Similar to private, but the symbol is passed through the assembler and
Chris Lattnere1eaf912009-08-24 04:32:16 +0000[diff] [blame]557 removed by the linker after evaluation. Note that (unlike private
558 symbols) linker_private symbols are subject to coalescing by the linker:
559 weak symbols get merged and redefinitions are rejected. However, unlike
560 normal strong symbols, they are removed by the linker from the final
561 linked image (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]562
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]563 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]564 <dd>Similar to private, but the value shows as a local symbol
565 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
566 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]567
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]568 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]569 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]570 into the object file corresponding to the LLVM module. They exist to
571 allow inlining and other optimizations to take place given knowledge of
572 the definition of the global, which is known to be somewhere outside the
573 module. Globals with <tt>available_externally</tt> linkage are allowed to
574 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
575 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]576
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]577 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]578 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]579 the same name when linkage occurs. This can be used to implement
580 some forms of inline functions, templates, or other code which must be
581 generated in each translation unit that uses it, but where the body may
582 be overridden with a more definitive definition later. Unreferenced
583 <tt>linkonce</tt> globals are allowed to be discarded. Note that
584 <tt>linkonce</tt> linkage does not actually allow the optimizer to
585 inline the body of this function into callers because it doesn't know if
586 this definition of the function is the definitive definition within the
587 program or whether it will be overridden by a stronger definition.
588 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
589 linkage.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]590
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]591 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]592 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
593 <tt>linkonce</tt> linkage, except that unreferenced globals with
594 <tt>weak</tt> linkage may not be discarded. This is used for globals that
595 are declared "weak" in C source code.</dd>
596
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]597 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]598 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
599 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
600 global scope.
601 Symbols with "<tt>common</tt>" linkage are merged in the same way as
602 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]603 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]604 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]605 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
606 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]607
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]608
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]609 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]610 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]611 pointer to array type. When two global variables with appending linkage
612 are linked together, the two global arrays are appended together. This is
613 the LLVM, typesafe, equivalent of having the system linker append together
614 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]615
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]616 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]617 <dd>The semantics of this linkage follow the ELF object file model: the symbol
618 is weak until linked, if not linked, the symbol becomes null instead of
619 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]620
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]621 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
622 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]623 <dd>Some languages allow differing globals to be merged, such as two functions
624 with different semantics. Other languages, such as <tt>C++</tt>, ensure
625 that only equivalent globals are ever merged (the "one definition rule" -
626 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
627 and <tt>weak_odr</tt> linkage types to indicate that the global will only
628 be merged with equivalent globals. These linkage types are otherwise the
629 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]630
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]631 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]632 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]633 visible, meaning that it participates in linkage and can be used to
634 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]635</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]636
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]637<p>The next two types of linkage are targeted for Microsoft Windows platform
638 only. They are designed to support importing (exporting) symbols from (to)
639 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]640
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]641<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]642 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]643 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]644 or variable via a global pointer to a pointer that is set up by the DLL
645 exporting the symbol. On Microsoft Windows targets, the pointer name is
646 formed by combining <code>__imp_</code> and the function or variable
647 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]648
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]649 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]650 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]651 pointer to a pointer in a DLL, so that it can be referenced with the
652 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
653 name is formed by combining <code>__imp_</code> and the function or
654 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]655</dl>
656
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]657<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
658 another module defined a "<tt>.LC0</tt>" variable and was linked with this
659 one, one of the two would be renamed, preventing a collision. Since
660 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
661 declarations), they are accessible outside of the current module.</p>
662
663<p>It is illegal for a function <i>declaration</i> to have any linkage type
664 other than "externally visible", <tt>dllimport</tt>
665 or <tt>extern_weak</tt>.</p>
666
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]667<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]668 or <tt>weak_odr</tt> linkages.</p>
669
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]670</div>
671
672<!-- ======================================================================= -->
673<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]674 <a name="callingconv">Calling Conventions</a>
675</div>
676
677<div class="doc_text">
678
679<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]680 and <a href="#i_invoke">invokes</a> can all have an optional calling
681 convention specified for the call. The calling convention of any pair of
682 dynamic caller/callee must match, or the behavior of the program is
683 undefined. The following calling conventions are supported by LLVM, and more
684 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]685
686<dl>
687 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]688 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]689 specified) matches the target C calling conventions. This calling
690 convention supports varargs function calls and tolerates some mismatch in
691 the declared prototype and implemented declaration of the function (as
692 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]693
694 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]695 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]696 (e.g. by passing things in registers). This calling convention allows the
697 target to use whatever tricks it wants to produce fast code for the
698 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]699 (Application Binary Interface).
700 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]701 when this or the GHC convention is used.</a> This calling convention
702 does not support varargs and requires the prototype of all callees to
703 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]704
705 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]706 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]707 as possible under the assumption that the call is not commonly executed.
708 As such, these calls often preserve all registers so that the call does
709 not break any live ranges in the caller side. This calling convention
710 does not support varargs and requires the prototype of all callees to
711 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]712
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]713 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
714 <dd>This calling convention has been implemented specifically for use by the
715 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
716 It passes everything in registers, going to extremes to achieve this by
717 disabling callee save registers. This calling convention should not be
718 used lightly but only for specific situations such as an alternative to
719 the <em>register pinning</em> performance technique often used when
720 implementing functional programming languages.At the moment only X86
721 supports this convention and it has the following limitations:
722 <ul>
723 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
724 floating point types are supported.</li>
725 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
726 6 floating point parameters.</li>
727 </ul>
728 This calling convention supports
729 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
730 requires both the caller and callee are using it.
731 </dd>
732
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]733 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]734 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]735 target-specific calling conventions to be used. Target specific calling
736 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]737</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]738
739<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]740 support Pascal conventions or any other well-known target-independent
741 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]742
743</div>
744
745<!-- ======================================================================= -->
746<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]747 <a name="visibility">Visibility Styles</a>
748</div>
749
750<div class="doc_text">
751
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]752<p>All Global Variables and Functions have one of the following visibility
753 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]754
755<dl>
756 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]757 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]758 that the declaration is visible to other modules and, in shared libraries,
759 means that the declared entity may be overridden. On Darwin, default
760 visibility means that the declaration is visible to other modules. Default
761 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]762
763 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]764 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]765 object if they are in the same shared object. Usually, hidden visibility
766 indicates that the symbol will not be placed into the dynamic symbol
767 table, so no other module (executable or shared library) can reference it
768 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]769
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]770 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]771 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]772 the dynamic symbol table, but that references within the defining module
773 will bind to the local symbol. That is, the symbol cannot be overridden by
774 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]775</dl>
776
777</div>
778
779<!-- ======================================================================= -->
780<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]781 <a name="namedtypes">Named Types</a>
782</div>
783
784<div class="doc_text">
785
786<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]787 it easier to read the IR and make the IR more condensed (particularly when
788 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]789
790<div class="doc_code">
791<pre>
792%mytype = type { %mytype*, i32 }
793</pre>
794</div>
795
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]796<p>You may give a name to any <a href="#typesystem">type</a> except
797 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
798 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]799
800<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]801 and that you can therefore specify multiple names for the same type. This
802 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
803 uses structural typing, the name is not part of the type. When printing out
804 LLVM IR, the printer will pick <em>one name</em> to render all types of a
805 particular shape. This means that if you have code where two different
806 source types end up having the same LLVM type, that the dumper will sometimes
807 print the "wrong" or unexpected type. This is an important design point and
808 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]809
810</div>
811
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]812<!-- ======================================================================= -->
813<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]814 <a name="globalvars">Global Variables</a>
815</div>
816
817<div class="doc_text">
818
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]819<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]820 instead of run-time. Global variables may optionally be initialized, may
821 have an explicit section to be placed in, and may have an optional explicit
822 alignment specified. A variable may be defined as "thread_local", which
823 means that it will not be shared by threads (each thread will have a
824 separated copy of the variable). A variable may be defined as a global
825 "constant," which indicates that the contents of the variable
826 will <b>never</b> be modified (enabling better optimization, allowing the
827 global data to be placed in the read-only section of an executable, etc).
828 Note that variables that need runtime initialization cannot be marked
829 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]830
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]831<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
832 constant, even if the final definition of the global is not. This capability
833 can be used to enable slightly better optimization of the program, but
834 requires the language definition to guarantee that optimizations based on the
835 'constantness' are valid for the translation units that do not include the
836 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]837
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]838<p>As SSA values, global variables define pointer values that are in scope
839 (i.e. they dominate) all basic blocks in the program. Global variables
840 always define a pointer to their "content" type because they describe a
841 region of memory, and all memory objects in LLVM are accessed through
842 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]843
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]844<p>A global variable may be declared to reside in a target-specific numbered
845 address space. For targets that support them, address spaces may affect how
846 optimizations are performed and/or what target instructions are used to
847 access the variable. The default address space is zero. The address space
848 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]849
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]850<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]851 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]852
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]853<p>An explicit alignment may be specified for a global. If not present, or if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]854 the alignment is set to zero, the alignment of the global is set by the
855 target to whatever it feels convenient. If an explicit alignment is
856 specified, the global is forced to have at least that much alignment. All
857 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]858
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]859<p>For example, the following defines a global in a numbered address space with
860 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]861
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]862<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]863<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]864@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]865</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]866</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]867
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]868</div>
869
870
871<!-- ======================================================================= -->
872<div class="doc_subsection">
873 <a name="functionstructure">Functions</a>
874</div>
875
876<div class="doc_text">
877
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]878<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]879 optional <a href="#linkage">linkage type</a>, an optional
880 <a href="#visibility">visibility style</a>, an optional
881 <a href="#callingconv">calling convention</a>, a return type, an optional
882 <a href="#paramattrs">parameter attribute</a> for the return type, a function
883 name, a (possibly empty) argument list (each with optional
884 <a href="#paramattrs">parameter attributes</a>), optional
885 <a href="#fnattrs">function attributes</a>, an optional section, an optional
886 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
887 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]888
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]889<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
890 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]891 <a href="#visibility">visibility style</a>, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]892 <a href="#callingconv">calling convention</a>, a return type, an optional
893 <a href="#paramattrs">parameter attribute</a> for the return type, a function
894 name, a possibly empty list of arguments, an optional alignment, and an
895 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]896
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]897<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]898 (Control Flow Graph) for the function. Each basic block may optionally start
899 with a label (giving the basic block a symbol table entry), contains a list
900 of instructions, and ends with a <a href="#terminators">terminator</a>
901 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]902
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]903<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]904 executed on entrance to the function, and it is not allowed to have
905 predecessor basic blocks (i.e. there can not be any branches to the entry
906 block of a function). Because the block can have no predecessors, it also
907 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]908
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]909<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]910 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]911
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]912<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]913 the alignment is set to zero, the alignment of the function is set by the
914 target to whatever it feels convenient. If an explicit alignment is
915 specified, the function is forced to have at least that much alignment. All
916 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]917
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]918<h5>Syntax:</h5>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]919<div class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]920<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]921define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]922 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
923 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
924 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
925 [<a href="#gc">gc</a>] { ... }
926</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]927</div>
928
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]929</div>
930
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]931<!-- ======================================================================= -->
932<div class="doc_subsection">
933 <a name="aliasstructure">Aliases</a>
934</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]935
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]936<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]937
938<p>Aliases act as "second name" for the aliasee value (which can be either
939 function, global variable, another alias or bitcast of global value). Aliases
940 may have an optional <a href="#linkage">linkage type</a>, and an
941 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]942
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]943<h5>Syntax:</h5>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]944<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]945<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]946@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]947</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]948</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]949
950</div>
951
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]952<!-- ======================================================================= -->
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]953<div class="doc_subsection">
954 <a name="namedmetadatastructure">Named Metadata</a>
955</div>
956
957<div class="doc_text">
958
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]959<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
960 nodes</a> (but not metadata strings) and null are the only valid operands for
961 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]962
963<h5>Syntax:</h5>
964<div class="doc_code">
965<pre>
966!1 = metadata !{metadata !"one"}
967!name = !{null, !1}
968</pre>
969</div>
970
971</div>
972
973<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]974<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]975
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]976<div class="doc_text">
977
978<p>The return type and each parameter of a function type may have a set of
979 <i>parameter attributes</i> associated with them. Parameter attributes are
980 used to communicate additional information about the result or parameters of
981 a function. Parameter attributes are considered to be part of the function,
982 not of the function type, so functions with different parameter attributes
983 can have the same function type.</p>
984
985<p>Parameter attributes are simple keywords that follow the type specified. If
986 multiple parameter attributes are needed, they are space separated. For
987 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]988
989<div class="doc_code">
990<pre>
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]991declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]992declare i32 @atoi(i8 zeroext)
993declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]994</pre>
995</div>
996
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]997<p>Note that any attributes for the function result (<tt>nounwind</tt>,
998 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]999
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1000<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1001
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1002<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1003 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1004 <dd>This indicates to the code generator that the parameter or return value
1005 should be zero-extended to a 32-bit value by the caller (for a parameter)
1006 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1007
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1008 <dt><tt><b>signext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1009 <dd>This indicates to the code generator that the parameter or return value
1010 should be sign-extended to a 32-bit value by the caller (for a parameter)
1011 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1012
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1013 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1014 <dd>This indicates that this parameter or return value should be treated in a
1015 special target-dependent fashion during while emitting code for a function
1016 call or return (usually, by putting it in a register as opposed to memory,
1017 though some targets use it to distinguish between two different kinds of
1018 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1019
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1020 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1021 <dd>This indicates that the pointer parameter should really be passed by value
1022 to the function. The attribute implies that a hidden copy of the pointee
1023 is made between the caller and the callee, so the callee is unable to
1024 modify the value in the callee. This attribute is only valid on LLVM
1025 pointer arguments. It is generally used to pass structs and arrays by
1026 value, but is also valid on pointers to scalars. The copy is considered
1027 to belong to the caller not the callee (for example,
1028 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1029 <tt>byval</tt> parameters). This is not a valid attribute for return
1030 values. The byval attribute also supports specifying an alignment with
1031 the align attribute. This has a target-specific effect on the code
1032 generator that usually indicates a desired alignment for the synthesized
1033 stack slot.</dd>
1034
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1035 <dt><tt><b>sret</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1036 <dd>This indicates that the pointer parameter specifies the address of a
1037 structure that is the return value of the function in the source program.
1038 This pointer must be guaranteed by the caller to be valid: loads and
1039 stores to the structure may be assumed by the callee to not to trap. This
1040 may only be applied to the first parameter. This is not a valid attribute
1041 for return values. </dd>
1042
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1043 <dt><tt><b>noalias</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1044 <dd>This indicates that the pointer does not alias any global or any other
1045 parameter. The caller is responsible for ensuring that this is the
1046 case. On a function return value, <tt>noalias</tt> additionally indicates
1047 that the pointer does not alias any other pointers visible to the
1048 caller. For further details, please see the discussion of the NoAlias
1049 response in
1050 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
1051 analysis</a>.</dd>
1052
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1053 <dt><tt><b>nocapture</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1054 <dd>This indicates that the callee does not make any copies of the pointer
1055 that outlive the callee itself. This is not a valid attribute for return
1056 values.</dd>
1057
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1058 <dt><tt><b>nest</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1059 <dd>This indicates that the pointer parameter can be excised using the
1060 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1061 attribute for return values.</dd>
1062</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1063
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1064</div>
1065
1066<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1067<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1068 <a name="gc">Garbage Collector Names</a>
1069</div>
1070
1071<div class="doc_text">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1072
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1073<p>Each function may specify a garbage collector name, which is simply a
1074 string:</p>
1075
1076<div class="doc_code">
1077<pre>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1078define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1079</pre>
1080</div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1081
1082<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1083 collector which will cause the compiler to alter its output in order to
1084 support the named garbage collection algorithm.</p>
1085
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1086</div>
1087
1088<!-- ======================================================================= -->
1089<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1090 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1091</div>
1092
1093<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1094
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1095<p>Function attributes are set to communicate additional information about a
1096 function. Function attributes are considered to be part of the function, not
1097 of the function type, so functions with different parameter attributes can
1098 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1099
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1100<p>Function attributes are simple keywords that follow the type specified. If
1101 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1102
1103<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1104<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1105define void @f() noinline { ... }
1106define void @f() alwaysinline { ... }
1107define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1108define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1109</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1110</div>
1111
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1112<dl>
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1113 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1114 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1115 the backend should forcibly align the stack pointer. Specify the
1116 desired alignment, which must be a power of two, in parentheses.
1117
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1118 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1119 <dd>This attribute indicates that the inliner should attempt to inline this
1120 function into callers whenever possible, ignoring any active inlining size
1121 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1122
Jakob Stoklund Olesen570a4a52010-02-06 01:16:28 +0000[diff] [blame]1123 <dt><tt><b>inlinehint</b></tt></dt>
1124 <dd>This attribute indicates that the source code contained a hint that inlining
1125 this function is desirable (such as the "inline" keyword in C/C++). It
1126 is just a hint; it imposes no requirements on the inliner.</dd>
1127
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1128 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1129 <dd>This attribute indicates that the inliner should never inline this
1130 function in any situation. This attribute may not be used together with
1131 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1132
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1133 <dt><tt><b>optsize</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1134 <dd>This attribute suggests that optimization passes and code generator passes
1135 make choices that keep the code size of this function low, and otherwise
1136 do optimizations specifically to reduce code size.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1137
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1138 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1139 <dd>This function attribute indicates that the function never returns
1140 normally. This produces undefined behavior at runtime if the function
1141 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1142
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1143 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1144 <dd>This function attribute indicates that the function never returns with an
1145 unwind or exceptional control flow. If the function does unwind, its
1146 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1147
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1148 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1149 <dd>This attribute indicates that the function computes its result (or decides
1150 to unwind an exception) based strictly on its arguments, without
1151 dereferencing any pointer arguments or otherwise accessing any mutable
1152 state (e.g. memory, control registers, etc) visible to caller functions.
1153 It does not write through any pointer arguments
1154 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1155 changes any state visible to callers. This means that it cannot unwind
1156 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1157 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1158
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1159 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1160 <dd>This attribute indicates that the function does not write through any
1161 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1162 arguments) or otherwise modify any state (e.g. memory, control registers,
1163 etc) visible to caller functions. It may dereference pointer arguments
1164 and read state that may be set in the caller. A readonly function always
1165 returns the same value (or unwinds an exception identically) when called
1166 with the same set of arguments and global state. It cannot unwind an
1167 exception by calling the <tt>C++</tt> exception throwing methods, but may
1168 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1169
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1170 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1171 <dd>This attribute indicates that the function should emit a stack smashing
1172 protector. It is in the form of a "canary"&mdash;a random value placed on
1173 the stack before the local variables that's checked upon return from the
1174 function to see if it has been overwritten. A heuristic is used to
1175 determine if a function needs stack protectors or not.<br>
1176<br>
1177 If a function that has an <tt>ssp</tt> attribute is inlined into a
1178 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1179 function will have an <tt>ssp</tt> attribute.</dd>
1180
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1181 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1182 <dd>This attribute indicates that the function should <em>always</em> emit a
1183 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1184 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1185<br>
1186 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1187 function that doesn't have an <tt>sspreq</tt> attribute or which has
1188 an <tt>ssp</tt> attribute, then the resulting function will have
1189 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1190
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1191 <dt><tt><b>noredzone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1192 <dd>This attribute indicates that the code generator should not use a red
1193 zone, even if the target-specific ABI normally permits it.</dd>
1194
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1195 <dt><tt><b>noimplicitfloat</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1196 <dd>This attributes disables implicit floating point instructions.</dd>
1197
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1198 <dt><tt><b>naked</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1199 <dd>This attribute disables prologue / epilogue emission for the function.
1200 This can have very system-specific consequences.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1201</dl>
1202
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1203</div>
1204
1205<!-- ======================================================================= -->
1206<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1207 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1208</div>
1209
1210<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1211
1212<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1213 the GCC "file scope inline asm" blocks. These blocks are internally
1214 concatenated by LLVM and treated as a single unit, but may be separated in
1215 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1216
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1217<div class="doc_code">
1218<pre>
1219module asm "inline asm code goes here"
1220module asm "more can go here"
1221</pre>
1222</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1223
1224<p>The strings can contain any character by escaping non-printable characters.
1225 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]1226 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1227
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1228<p>The inline asm code is simply printed to the machine code .s file when
1229 assembly code is generated.</p>
1230
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1231</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1232
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1233<!-- ======================================================================= -->
1234<div class="doc_subsection">
1235 <a name="datalayout">Data Layout</a>
1236</div>
1237
1238<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1239
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1240<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1241 data is to be laid out in memory. The syntax for the data layout is
1242 simply:</p>
1243
1244<div class="doc_code">
1245<pre>
1246target datalayout = "<i>layout specification</i>"
1247</pre>
1248</div>
1249
1250<p>The <i>layout specification</i> consists of a list of specifications
1251 separated by the minus sign character ('-'). Each specification starts with
1252 a letter and may include other information after the letter to define some
1253 aspect of the data layout. The specifications accepted are as follows:</p>
1254
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1255<dl>
1256 <dt><tt>E</tt></dt>
1257 <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]1258 bits with the most significance have the lowest address location.</dd>
1259
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1260 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1261 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1262 the bits with the least significance have the lowest address
1263 location.</dd>
1264
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1265 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1266 <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]1267 <i>preferred</i> alignments. All sizes are in bits. Specifying
1268 the <i>pref</i> alignment is optional. If omitted, the
1269 preceding <tt>:</tt> should be omitted too.</dd>
1270
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1271 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1272 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1273 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1274
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1275 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1276 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1277 <i>size</i>.</dd>
1278
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1279 <dt><tt>f<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 floating point type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1281 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1282 (double).</dd>
1283
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1284 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1285 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1286 <i>size</i>.</dd>
1287
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1288 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1289 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1290 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1291
1292 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1293 <dd>This specifies a set of native integer widths for the target CPU
1294 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1295 "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]1296 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1297 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1298</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1299
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1300<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1301 default set of specifications which are then (possibly) overriden by the
1302 specifications in the <tt>datalayout</tt> keyword. The default specifications
1303 are given in this list:</p>
1304
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1305<ul>
1306 <li><tt>E</tt> - big endian</li>
Dan Gohmanfdf2e8c2010-02-23 02:44:03 +0000[diff] [blame]1307 <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]1308 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1309 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1310 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1311 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1312 <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]1313 alignment of 64-bits</li>
1314 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1315 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1316 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1317 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1318 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1319 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1320</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1321
1322<p>When LLVM is determining the alignment for a given type, it uses the
1323 following rules:</p>
1324
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1325<ol>
1326 <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]1327 specification is used.</li>
1328
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1329 <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]1330 smallest integer type that is larger than the bitwidth of the sought type
1331 is used. If none of the specifications are larger than the bitwidth then
1332 the the largest integer type is used. For example, given the default
1333 specifications above, the i7 type will use the alignment of i8 (next
1334 largest) while both i65 and i256 will use the alignment of i64 (largest
1335 specified).</li>
1336
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1337 <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]1338 largest vector type that is smaller than the sought vector type will be
1339 used as a fall back. This happens because &lt;128 x double&gt; can be
1340 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1341</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1342
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1343</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1344
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1345<!-- ======================================================================= -->
1346<div class="doc_subsection">
1347 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1348</div>
1349
1350<div class="doc_text">
1351
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1352<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1353with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1354is undefined. Pointer values are associated with address ranges
1355according to the following rules:</p>
1356
1357<ul>
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1358 <li>A pointer value formed from a
1359 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1360 is associated with the addresses associated with the first operand
1361 of the <tt>getelementptr</tt>.</li>
1362 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1363 range of the variable's storage.</li>
1364 <li>The result value of an allocation instruction is associated with
1365 the address range of the allocated storage.</li>
1366 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1367 no address.</li>
1368 <li>A pointer value formed by an
1369 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1370 address ranges of all pointer values that contribute (directly or
1371 indirectly) to the computation of the pointer's value.</li>
1372 <li>The result value of a
1373 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1374 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1375 <li>An integer constant other than zero or a pointer value returned
1376 from a function not defined within LLVM may be associated with address
1377 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1378 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1379 allocated by mechanisms provided by LLVM.</li>
1380 </ul>
1381
1382<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1383<tt><a href="#i_load">load</a></tt> merely indicates the size and
1384alignment of the memory from which to load, as well as the
1385interpretation of the value. The first operand of a
1386<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1387and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1388
1389<p>Consequently, type-based alias analysis, aka TBAA, aka
1390<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1391LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1392additional information which specialized optimization passes may use
1393to implement type-based alias analysis.</p>
1394
1395</div>
1396
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1397<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1398<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1399<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1400
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1401<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1402
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1403<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1404 intermediate representation. Being typed enables a number of optimizations
1405 to be performed on the intermediate representation directly, without having
1406 to do extra analyses on the side before the transformation. A strong type
1407 system makes it easier to read the generated code and enables novel analyses
1408 and transformations that are not feasible to perform on normal three address
1409 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1410
1411</div>
1412
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1413<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1414<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1415Classifications</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1416
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1417<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1418
1419<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1420
1421<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1422 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1423 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1424 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1425 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1426 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1427 </tr>
1428 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1429 <td><a href="#t_floating">floating point</a></td>
1430 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1431 </tr>
1432 <tr>
1433 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1434 <td><a href="#t_integer">integer</a>,
1435 <a href="#t_floating">floating point</a>,
1436 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1437 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1438 <a href="#t_struct">structure</a>,
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1439 <a href="#t_union">union</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1440 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1441 <a href="#t_label">label</a>,
1442 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1443 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1444 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1445 <tr>
1446 <td><a href="#t_primitive">primitive</a></td>
1447 <td><a href="#t_label">label</a>,
1448 <a href="#t_void">void</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1449 <a href="#t_floating">floating point</a>,
1450 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1451 </tr>
1452 <tr>
1453 <td><a href="#t_derived">derived</a></td>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1454 <td><a href="#t_array">array</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1455 <a href="#t_function">function</a>,
1456 <a href="#t_pointer">pointer</a>,
1457 <a href="#t_struct">structure</a>,
1458 <a href="#t_pstruct">packed structure</a>,
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1459 <a href="#t_union">union</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1460 <a href="#t_vector">vector</a>,
1461 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1462 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1463 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1464 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1465</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1466
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1467<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1468 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1469 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1470
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1471</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1472
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1473<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1474<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1475
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1476<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1477
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1478<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1479 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1480
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1481</div>
1482
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1483<!-- _______________________________________________________________________ -->
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1484<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1485
1486<div class="doc_text">
1487
1488<h5>Overview:</h5>
1489<p>The integer type is a very simple type that simply specifies an arbitrary
1490 bit width for the integer type desired. Any bit width from 1 bit to
1491 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1492
1493<h5>Syntax:</h5>
1494<pre>
1495 iN
1496</pre>
1497
1498<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1499 value.</p>
1500
1501<h5>Examples:</h5>
1502<table class="layout">
1503 <tr class="layout">
1504 <td class="left"><tt>i1</tt></td>
1505 <td class="left">a single-bit integer.</td>
1506 </tr>
1507 <tr class="layout">
1508 <td class="left"><tt>i32</tt></td>
1509 <td class="left">a 32-bit integer.</td>
1510 </tr>
1511 <tr class="layout">
1512 <td class="left"><tt>i1942652</tt></td>
1513 <td class="left">a really big integer of over 1 million bits.</td>
1514 </tr>
1515</table>
1516
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1517</div>
1518
1519<!-- _______________________________________________________________________ -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1520<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1521
1522<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1523
1524<table>
1525 <tbody>
1526 <tr><th>Type</th><th>Description</th></tr>
1527 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1528 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1529 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1530 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1531 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1532 </tbody>
1533</table>
1534
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1535</div>
1536
1537<!-- _______________________________________________________________________ -->
1538<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1539
1540<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1541
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1542<h5>Overview:</h5>
1543<p>The void type does not represent any value and has no size.</p>
1544
1545<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1546<pre>
1547 void
1548</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1549
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1550</div>
1551
1552<!-- _______________________________________________________________________ -->
1553<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1554
1555<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1556
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1557<h5>Overview:</h5>
1558<p>The label type represents code labels.</p>
1559
1560<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1561<pre>
1562 label
1563</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1564
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1565</div>
1566
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1567<!-- _______________________________________________________________________ -->
1568<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1569
1570<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1571
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1572<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1573<p>The metadata type represents embedded metadata. No derived types may be
1574 created from metadata except for <a href="#t_function">function</a>
1575 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1576
1577<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1578<pre>
1579 metadata
1580</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1581
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1582</div>
1583
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1584
1585<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1586<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1587
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1588<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1589
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1590<p>The real power in LLVM comes from the derived types in the system. This is
1591 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1592 useful types. Each of these types contain one or more element types which
1593 may be a primitive type, or another derived type. For example, it is
1594 possible to have a two dimensional array, using an array as the element type
1595 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1596
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1597
1598</div>
1599
1600<!-- _______________________________________________________________________ -->
1601<div class="doc_subsubsection"> <a name="t_aggregate">Aggregate Types</a> </div>
1602
1603<div class="doc_text">
1604
1605<p>Aggregate Types are a subset of derived types that can contain multiple
1606 member types. <a href="#t_array">Arrays</a>,
1607 <a href="#t_struct">structs</a>, <a href="#t_vector">vectors</a> and
1608 <a href="#t_union">unions</a> are aggregate types.</p>
1609
1610</div>
1611
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1612</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1613
1614<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1615<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1616
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1617<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1618
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1619<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1620<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1621 sequentially in memory. The array type requires a size (number of elements)
1622 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1623
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1624<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1625<pre>
1626 [&lt;# elements&gt; x &lt;elementtype&gt;]
1627</pre>
1628
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1629<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1630 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1631
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1632<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1633<table class="layout">
1634 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1635 <td class="left"><tt>[40 x i32]</tt></td>
1636 <td class="left">Array of 40 32-bit integer values.</td>
1637 </tr>
1638 <tr class="layout">
1639 <td class="left"><tt>[41 x i32]</tt></td>
1640 <td class="left">Array of 41 32-bit integer values.</td>
1641 </tr>
1642 <tr class="layout">
1643 <td class="left"><tt>[4 x i8]</tt></td>
1644 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1645 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1646</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1647<p>Here are some examples of multidimensional arrays:</p>
1648<table class="layout">
1649 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1650 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1651 <td class="left">3x4 array of 32-bit integer values.</td>
1652 </tr>
1653 <tr class="layout">
1654 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1655 <td class="left">12x10 array of single precision floating point values.</td>
1656 </tr>
1657 <tr class="layout">
1658 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1659 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1660 </tr>
1661</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1662
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1663<p>There is no restriction on indexing beyond the end of the array implied by
1664 a static type (though there are restrictions on indexing beyond the bounds
1665 of an allocated object in some cases). This means that single-dimension
1666 'variable sized array' addressing can be implemented in LLVM with a zero
1667 length array type. An implementation of 'pascal style arrays' in LLVM could
1668 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1669
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1670</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1671
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1672<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1673<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1674
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1675<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1676
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1677<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1678<p>The function type can be thought of as a function signature. It consists of
1679 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]1680 function type is a scalar type, a void type, a struct type, or a union
1681 type. If the return type is a struct type then all struct elements must be
1682 of first class types, and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1683
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1684<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1685<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1686 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1687</pre>
1688
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1689<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]1690 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1691 which indicates that the function takes a variable number of arguments.
1692 Variable argument functions can access their arguments with
1693 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1694 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1695 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1696
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1697<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1698<table class="layout">
1699 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1700 <td class="left"><tt>i32 (i32)</tt></td>
1701 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1702 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1703 </tr><tr class="layout">
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1704 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1705 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1706 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1707 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1708 returning <tt>float</tt>.
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1709 </td>
1710 </tr><tr class="layout">
1711 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1712 <td class="left">A vararg function that takes at least one
1713 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1714 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1715 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1716 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1717 </tr><tr class="layout">
1718 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1719 <td class="left">A function taking an <tt>i32</tt>, returning a
1720 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1721 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1722 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1723</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1724
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1725</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1726
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1727<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1728<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1729
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1730<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1731
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1732<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1733<p>The structure type is used to represent a collection of data members together
1734 in memory. The packing of the field types is defined to match the ABI of the
1735 underlying processor. The elements of a structure may be any type that has a
1736 size.</p>
1737
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]1738<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1739 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1740 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1741 Structures in registers are accessed using the
1742 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1743 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1744<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1745<pre>
1746 { &lt;type list&gt; }
1747</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1748
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1749<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1750<table class="layout">
1751 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1752 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1753 <td class="left">A triple of three <tt>i32</tt> values</td>
1754 </tr><tr class="layout">
1755 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1756 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1757 second element is a <a href="#t_pointer">pointer</a> to a
1758 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1759 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1760 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1761</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1762
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1763</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1764
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1765<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1766<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1767</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1768
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1769<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1770
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1771<h5>Overview:</h5>
1772<p>The packed structure type is used to represent a collection of data members
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1773 together in memory. There is no padding between fields. Further, the
1774 alignment of a packed structure is 1 byte. The elements of a packed
1775 structure may be any type that has a size.</p>
1776
1777<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1778 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1779 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1780
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1781<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1782<pre>
1783 &lt; { &lt;type list&gt; } &gt;
1784</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1785
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1786<h5>Examples:</h5>
1787<table class="layout">
1788 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1789 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1790 <td class="left">A triple of three <tt>i32</tt> values</td>
1791 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1792 <td class="left">
1793<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1794 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1795 second element is a <a href="#t_pointer">pointer</a> to a
1796 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1797 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1798 </tr>
1799</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1800
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1801</div>
1802
1803<!-- _______________________________________________________________________ -->
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1804<div class="doc_subsubsection"> <a name="t_union">Union Type</a> </div>
1805
1806<div class="doc_text">
1807
1808<h5>Overview:</h5>
1809<p>A union type describes an object with size and alignment suitable for
1810 an object of any one of a given set of types (also known as an "untagged"
1811 union). It is similar in concept and usage to a
1812 <a href="#t_struct">struct</a>, except that all members of the union
1813 have an offset of zero. The elements of a union may be any type that has a
1814 size. Unions must have at least one member - empty unions are not allowed.
1815 </p>
1816
1817<p>The size of the union as a whole will be the size of its largest member,
1818 and the alignment requirements of the union as a whole will be the largest
1819 alignment requirement of any member.</p>
1820
Dan Gohman2eddfef2010-02-25 16:51:31 +0000[diff] [blame]1821<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]1822 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1823 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1824 Since all members are at offset zero, the getelementptr instruction does
1825 not affect the address, only the type of the resulting pointer.</p>
1826
1827<h5>Syntax:</h5>
1828<pre>
1829 union { &lt;type list&gt; }
1830</pre>
1831
1832<h5>Examples:</h5>
1833<table class="layout">
1834 <tr class="layout">
1835 <td class="left"><tt>union { i32, i32*, float }</tt></td>
1836 <td class="left">A union of three types: an <tt>i32</tt>, a pointer to
1837 an <tt>i32</tt>, and a <tt>float</tt>.</td>
1838 </tr><tr class="layout">
1839 <td class="left">
1840 <tt>union {&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1841 <td class="left">A union, where the first element is a <tt>float</tt> and the
1842 second element is a <a href="#t_pointer">pointer</a> to a
1843 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1844 an <tt>i32</tt>.</td>
1845 </tr>
1846</table>
1847
1848</div>
1849
1850<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1851<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1852
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1853<div class="doc_text">
1854
1855<h5>Overview:</h5>
Dan Gohmanff3ef322010-02-25 16:50:07 +0000[diff] [blame]1856<p>The pointer type is used to specify memory locations.
1857 Pointers are commonly used to reference objects in memory.</p>
1858
1859<p>Pointer types may have an optional address space attribute defining the
1860 numbered address space where the pointed-to object resides. The default
1861 address space is number zero. The semantics of non-zero address
1862 spaces are target-specific.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1863
1864<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1865 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1866
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1867<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1868<pre>
1869 &lt;type&gt; *
1870</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1871
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1872<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1873<table class="layout">
1874 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1875 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1876 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1877 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1878 </tr>
1879 <tr class="layout">
1880 <td class="left"><tt>i32 (i32 *) *</tt></td>
1881 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1882 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1883 <tt>i32</tt>.</td>
1884 </tr>
1885 <tr class="layout">
1886 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1887 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1888 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1889 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1890</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1891
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1892</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1893
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1894<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1895<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1896
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1897<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1898
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1899<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1900<p>A vector type is a simple derived type that represents a vector of elements.
1901 Vector types are used when multiple primitive data are operated in parallel
1902 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]1903 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1904 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1905
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1906<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1907<pre>
1908 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1909</pre>
1910
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1911<p>The number of elements is a constant integer value; elementtype may be any
1912 integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1913
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1914<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1915<table class="layout">
1916 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1917 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1918 <td class="left">Vector of 4 32-bit integer values.</td>
1919 </tr>
1920 <tr class="layout">
1921 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1922 <td class="left">Vector of 8 32-bit floating-point values.</td>
1923 </tr>
1924 <tr class="layout">
1925 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1926 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1927 </tr>
1928</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1929
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1930</div>
1931
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1932<!-- _______________________________________________________________________ -->
1933<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1934<div class="doc_text">
1935
1936<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1937<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1938 corresponds (for example) to the C notion of a forward declared structure
1939 type. In LLVM, opaque types can eventually be resolved to any type (not just
1940 a structure type).</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1941
1942<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1943<pre>
1944 opaque
1945</pre>
1946
1947<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1948<table class="layout">
1949 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1950 <td class="left"><tt>opaque</tt></td>
1951 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1952 </tr>
1953</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1954
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1955</div>
1956
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1957<!-- ======================================================================= -->
1958<div class="doc_subsection">
1959 <a name="t_uprefs">Type Up-references</a>
1960</div>
1961
1962<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1963
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1964<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1965<p>An "up reference" allows you to refer to a lexically enclosing type without
1966 requiring it to have a name. For instance, a structure declaration may
1967 contain a pointer to any of the types it is lexically a member of. Example
1968 of up references (with their equivalent as named type declarations)
1969 include:</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1970
1971<pre>
Chris Lattner3060f5b2009-02-09 10:00:56 +0000[diff] [blame]1972 { \2 * } %x = type { %x* }
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1973 { \2 }* %y = type { %y }*
1974 \1* %z = type %z*
1975</pre>
1976
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1977<p>An up reference is needed by the asmprinter for printing out cyclic types
1978 when there is no declared name for a type in the cycle. Because the
1979 asmprinter does not want to print out an infinite type string, it needs a
1980 syntax to handle recursive types that have no names (all names are optional
1981 in llvm IR).</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1982
1983<h5>Syntax:</h5>
1984<pre>
1985 \&lt;level&gt;
1986</pre>
1987
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1988<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]1989
1990<h5>Examples:</h5>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1991<table class="layout">
1992 <tr class="layout">
1993 <td class="left"><tt>\1*</tt></td>
1994 <td class="left">Self-referential pointer.</td>
1995 </tr>
1996 <tr class="layout">
1997 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1998 <td class="left">Recursive structure where the upref refers to the out-most
1999 structure.</td>
2000 </tr>
2001</table>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2002
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2003</div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2004
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2005<!-- *********************************************************************** -->
2006<div class="doc_section"> <a name="constants">Constants</a> </div>
2007<!-- *********************************************************************** -->
2008
2009<div class="doc_text">
2010
2011<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2012 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2013
2014</div>
2015
2016<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]2017<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2018
2019<div class="doc_text">
2020
2021<dl>
2022 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2023 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]2024 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2025
2026 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2027 <dd>Standard integers (such as '4') are constants of
2028 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2029 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2030
2031 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2032 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2033 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2034 notation (see below). The assembler requires the exact decimal value of a
2035 floating-point constant. For example, the assembler accepts 1.25 but
2036 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2037 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2038
2039 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2040 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2041 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2042</dl>
2043
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2044<p>The one non-intuitive notation for constants is the hexadecimal form of
2045 floating point constants. For example, the form '<tt>double
2046 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2047 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2048 constants are required (and the only time that they are generated by the
2049 disassembler) is when a floating point constant must be emitted but it cannot
2050 be represented as a decimal floating point number in a reasonable number of
2051 digits. For example, NaN's, infinities, and other special values are
2052 represented in their IEEE hexadecimal format so that assembly and disassembly
2053 do not cause any bits to change in the constants.</p>
2054
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]2055<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2056 represented using the 16-digit form shown above (which matches the IEEE754
2057 representation for double); float values must, however, be exactly
2058 representable as IEE754 single precision. Hexadecimal format is always used
2059 for long double, and there are three forms of long double. The 80-bit format
2060 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2061 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2062 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2063 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2064 currently supported target uses this format. Long doubles will only work if
2065 they match the long double format on your target. All hexadecimal formats
2066 are big-endian (sign bit at the left).</p>
2067
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2068</div>
2069
2070<!-- ======================================================================= -->
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2071<div class="doc_subsection">
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2072<a name="aggregateconstants"></a> <!-- old anchor -->
2073<a name="complexconstants">Complex Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2074</div>
2075
2076<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2077
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2078<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2079 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2080
2081<dl>
2082 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2083 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2084 type definitions (a comma separated list of elements, surrounded by braces
2085 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2086 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2087 Structure constants must have <a href="#t_struct">structure type</a>, and
2088 the number and types of elements must match those specified by the
2089 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2090
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2091 <dt><b>Union constants</b></dt>
2092 <dd>Union constants are represented with notation similar to a structure with
2093 a single element - that is, a single typed element surrounded
2094 by braces (<tt>{}</tt>)). For example: "<tt>{ i32 4 }</tt>". The
2095 <a href="#t_union">union type</a> can be initialized with a single-element
2096 struct as long as the type of the struct element matches the type of
2097 one of the union members.</dd>
2098
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2099 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2100 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2101 definitions (a comma separated list of elements, surrounded by square
2102 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2103 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2104 the number and types of elements must match those specified by the
2105 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2106
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2107 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2108 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2109 definitions (a comma separated list of elements, surrounded by
2110 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2111 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2112 have <a href="#t_vector">vector type</a>, and the number and types of
2113 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2114
2115 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2116 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2117 value to zero of <em>any</em> type, including scalar and
2118 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2119 This is often used to avoid having to print large zero initializers
2120 (e.g. for large arrays) and is always exactly equivalent to using explicit
2121 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2122
2123 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2124 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2125 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2126 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2127 be interpreted as part of the instruction stream, metadata is a place to
2128 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2129</dl>
2130
2131</div>
2132
2133<!-- ======================================================================= -->
2134<div class="doc_subsection">
2135 <a name="globalconstants">Global Variable and Function Addresses</a>
2136</div>
2137
2138<div class="doc_text">
2139
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2140<p>The addresses of <a href="#globalvars">global variables</a>
2141 and <a href="#functionstructure">functions</a> are always implicitly valid
2142 (link-time) constants. These constants are explicitly referenced when
2143 the <a href="#identifiers">identifier for the global</a> is used and always
2144 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2145 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2146
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2147<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2148<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2149@X = global i32 17
2150@Y = global i32 42
2151@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2152</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2153</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2154
2155</div>
2156
2157<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]2158<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2159<div class="doc_text">
2160
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2161<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]2162 indicates that the user of the value may receive an unspecified bit-pattern.
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2163 Undefined values may be of any type (other than label or void) and be used
2164 anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2165
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2166<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2167 program is well defined no matter what value is used. This gives the
2168 compiler more freedom to optimize. Here are some examples of (potentially
2169 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2170
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2171
2172<div class="doc_code">
2173<pre>
2174 %A = add %X, undef
2175 %B = sub %X, undef
2176 %C = xor %X, undef
2177Safe:
2178 %A = undef
2179 %B = undef
2180 %C = undef
2181</pre>
2182</div>
2183
2184<p>This is safe because all of the output bits are affected by the undef bits.
2185Any output bit can have a zero or one depending on the input bits.</p>
2186
2187<div class="doc_code">
2188<pre>
2189 %A = or %X, undef
2190 %B = and %X, undef
2191Safe:
2192 %A = -1
2193 %B = 0
2194Unsafe:
2195 %A = undef
2196 %B = undef
2197</pre>
2198</div>
2199
2200<p>These logical operations have bits that are not always affected by the input.
2201For example, if "%X" has a zero bit, then the output of the 'and' operation will
2202always be a zero, no matter what the corresponding bit from the undef is. As
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2203such, 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]2204However, it is safe to assume that all bits of the undef could be 0, and
2205optimize the and to 0. Likewise, it is safe to assume that all the bits of
2206the 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]2207-1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2208
2209<div class="doc_code">
2210<pre>
2211 %A = select undef, %X, %Y
2212 %B = select undef, 42, %Y
2213 %C = select %X, %Y, undef
2214Safe:
2215 %A = %X (or %Y)
2216 %B = 42 (or %Y)
2217 %C = %Y
2218Unsafe:
2219 %A = undef
2220 %B = undef
2221 %C = undef
2222</pre>
2223</div>
2224
2225<p>This set of examples show that undefined select (and conditional branch)
2226conditions can go "either way" but they have to come from one of the two
2227operands. In the %A example, if %X and %Y were both known to have a clear low
2228bit, then %A would have to have a cleared low bit. However, in the %C example,
2229the optimizer is allowed to assume that the undef operand could be the same as
2230%Y, allowing the whole select to be eliminated.</p>
2231
2232
2233<div class="doc_code">
2234<pre>
2235 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2236
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2237 %B = undef
2238 %C = xor %B, %B
2239
2240 %D = undef
2241 %E = icmp lt %D, 4
2242 %F = icmp gte %D, 4
2243
2244Safe:
2245 %A = undef
2246 %B = undef
2247 %C = undef
2248 %D = undef
2249 %E = undef
2250 %F = undef
2251</pre>
2252</div>
2253
2254<p>This example points out that two undef operands are not necessarily the same.
2255This can be surprising to people (and also matches C semantics) where they
2256assume that "X^X" is always zero, even if X is undef. This isn't true for a
2257number of reasons, but the short answer is that an undef "variable" can
2258arbitrarily change its value over its "live range". This is true because the
2259"variable" doesn't actually <em>have a live range</em>. Instead, the value is
2260logically read from arbitrary registers that happen to be around when needed,
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]2261so the value is not necessarily consistent over time. In fact, %A and %C need
Chris Lattner349eb412009-09-08 15:13:16 +0000[diff] [blame]2262to have the same semantics or the core LLVM "replace all uses with" concept
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2263would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2264
2265<div class="doc_code">
2266<pre>
2267 %A = fdiv undef, %X
2268 %B = fdiv %X, undef
2269Safe:
2270 %A = undef
2271b: unreachable
2272</pre>
2273</div>
2274
2275<p>These examples show the crucial difference between an <em>undefined
2276value</em> and <em>undefined behavior</em>. An undefined value (like undef) is
2277allowed to have an arbitrary bit-pattern. This means that the %A operation
2278can be constant folded to undef because the undef could be an SNaN, and fdiv is
2279not (currently) defined on SNaN's. However, in the second example, we can make
2280a more aggressive assumption: because the undef is allowed to be an arbitrary
2281value, 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]2282has <em>undefined behavior</em>, we are allowed to assume that the operation
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2283does not execute at all. This allows us to delete the divide and all code after
2284it: since the undefined operation "can't happen", the optimizer can assume that
2285it occurs in dead code.
2286</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2287
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2288<div class="doc_code">
2289<pre>
2290a: store undef -> %X
2291b: store %X -> undef
2292Safe:
2293a: &lt;deleted&gt;
2294b: unreachable
2295</pre>
2296</div>
2297
2298<p>These examples reiterate the fdiv example: a store "of" an undefined value
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2299can be assumed to not have any effect: we can assume that the value is
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2300overwritten with bits that happen to match what was already there. However, a
2301store "to" an undefined location could clobber arbitrary memory, therefore, it
2302has undefined behavior.</p>
2303
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2304</div>
2305
2306<!-- ======================================================================= -->
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2307<div class="doc_subsection"><a name="trapvalues">Trap Values</a></div>
2308<div class="doc_text">
2309
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2310<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2311 instead of representing an unspecified bit pattern, they represent the
2312 fact that an instruction or constant expression which cannot evoke side
2313 effects has nevertheless detected a condition which results in undefined
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2314 behavior.</p>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2315
Dan Gohman698cbcb2010-04-24 22:15:58 +0000[diff] [blame]2316<p>Any non-void instruction or constant expression other than a non-intrinsic
2317 call, invoke, or phi with a trap operand has trap as its result value.
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2318 Any instruction with a trap operand which may have side effects emits
2319 those side effects as if it had an undef operand instead.</p>
2320
Dan Gohmanc30f6e12010-04-26 20:54:53 +0000[diff] [blame^]2321<p>If a <a href="#i_br"><tt>br</tt></a> or
2322 <a href="#i_switch"><tt>switch</tt></a> instruction has a trap value
2323 operand, all non-phi non-void instructions which control-depend on it
2324 have trap as their result value. If any instruction which
2325 control-depends on the <tt>br</tt> or <tt>switch</tt> invokes externally
2326 visible side effects, the behavior of the program is undefined.</p>
2327
2328<!-- FIXME: What about exceptions thrown from control-dependent instrs? -->
2329
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2330<p>For example, an <a href="#i_and"><tt>and</tt></a> of a trap value with
2331 zero still has a trap value result. Using that value as an index in a
2332 <a href="#i_getelementptr"><tt>getelementptr</tt></a> yields a trap
2333 result. Using that result as the address of a
2334 <a href="#i_store"><tt>store</tt></a> produces undefined behavior.</p>
2335
2336<p>There is currently no way of representing a trap constant in the IR; they
2337 only exist when produced by certain instructions, such as an
2338 <a href="#i_add"><tt>add</tt></a> with the <tt>nsw</tt> flag
2339 set, when overflow occurs.</p>
2340
2341</div>
2342
2343<!-- ======================================================================= -->
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]2344<div class="doc_subsection"><a name="blockaddress">Addresses of Basic
2345 Blocks</a></div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2346<div class="doc_text">
2347
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2348<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2349
2350<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2351 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2352 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2353
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2354<p>This value only has defined behavior when used as an operand to the
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2355 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction or for comparisons
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2356 against null. Pointer equality tests between labels addresses is undefined
2357 behavior - though, again, comparison against null is ok, and no label is
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]2358 equal to the null pointer. This may also be passed around as an opaque
2359 pointer sized value as long as the bits are not inspected. This allows
Chris Lattner3fd77ce2009-10-27 21:44:20 +0000[diff] [blame]2360 <tt>ptrtoint</tt> and arithmetic to be performed on these values so long as
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2361 the original value is reconstituted before the <tt>indirectbr</tt>.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2362
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]2363<p>Finally, some targets may provide defined semantics when
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2364 using the value as the operand to an inline assembly, but that is target
2365 specific.
2366 </p>
2367
2368</div>
2369
2370
2371<!-- ======================================================================= -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2372<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2373</div>
2374
2375<div class="doc_text">
2376
2377<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2378 to be used as constants. Constant expressions may be of
2379 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2380 operation that does not have side effects (e.g. load and call are not
2381 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2382
2383<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2384 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2385 <dd>Truncate a constant to another type. The bit size of CST must be larger
2386 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2387
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2388 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2389 <dd>Zero extend a constant to another type. The bit size of CST must be
2390 smaller or equal to the bit size of TYPE. Both types must be
2391 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2392
2393 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2394 <dd>Sign extend a constant to another type. The bit size of CST must be
2395 smaller or equal to the bit size of TYPE. Both types must be
2396 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2397
2398 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2399 <dd>Truncate a floating point constant to another floating point type. The
2400 size of CST must be larger than the size of TYPE. Both types must be
2401 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2402
2403 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2404 <dd>Floating point extend a constant to another type. The size of CST must be
2405 smaller or equal to the size of TYPE. Both types must be floating
2406 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2407
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]2408 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2409 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2410 constant. TYPE must be a scalar or vector integer type. CST must be of
2411 scalar or vector floating point type. Both CST and TYPE must be scalars,
2412 or vectors of the same number of elements. If the value won't fit in the
2413 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2414
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2415 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2416 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2417 constant. TYPE must be a scalar or vector integer type. CST must be of
2418 scalar or vector floating point type. Both CST and TYPE must be scalars,
2419 or vectors of the same number of elements. If the value won't fit in the
2420 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2421
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2422 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2423 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2424 constant. TYPE must be a scalar or vector floating point type. CST must be
2425 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2426 vectors of the same number of elements. If the value won't fit in the
2427 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2428
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2429 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2430 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2431 constant. TYPE must be a scalar or vector floating point type. CST must be
2432 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2433 vectors of the same number of elements. If the value won't fit in the
2434 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2435
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2436 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2437 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2438 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2439 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2440 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2441
2442 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2443 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2444 type. CST must be of integer type. The CST value is zero extended,
2445 truncated, or unchanged to make it fit in a pointer size. This one is
2446 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2447
2448 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2449 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2450 are the same as those for the <a href="#i_bitcast">bitcast
2451 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2452
2453 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]2454 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2455 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2456 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2457 instruction, the index list may have zero or more indexes, which are
2458 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2459
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2460 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2461 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2462
2463 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2464 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2465
2466 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2467 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2468
2469 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2470 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2471 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2472
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]2473 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2474 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2475 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2476
2477 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2478 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2479 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2480
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2481 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2482 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2483 be any of the <a href="#binaryops">binary</a>
2484 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2485 on operands are the same as those for the corresponding instruction
2486 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2487</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2488
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2489</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2490
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2491<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2492<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2493<!-- *********************************************************************** -->
2494
2495<!-- ======================================================================= -->
2496<div class="doc_subsection">
2497<a name="inlineasm">Inline Assembler Expressions</a>
2498</div>
2499
2500<div class="doc_text">
2501
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2502<p>LLVM supports inline assembler expressions (as opposed
2503 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2504 a special value. This value represents the inline assembler as a string
2505 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2506 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2507 expression has side effects, and a flag indicating whether the function
2508 containing the asm needs to align its stack conservatively. An example
2509 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2510
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2511<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2512<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2513i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2514</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2515</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2516
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2517<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2518 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2519 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2520
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2521<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2522<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2523%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]2524</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2525</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2526
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2527<p>Inline asms with side effects not visible in the constraint list must be
2528 marked as having side effects. This is done through the use of the
2529 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2530
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2531<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2532<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2533call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2534</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2535</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2536
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2537<p>In some cases inline asms will contain code that will not work unless the
2538 stack is aligned in some way, such as calls or SSE instructions on x86,
2539 yet will not contain code that does that alignment within the asm.
2540 The compiler should make conservative assumptions about what the asm might
2541 contain and should generate its usual stack alignment code in the prologue
2542 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2543
2544<div class="doc_code">
2545<pre>
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2546call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2547</pre>
2548</div>
2549
2550<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2551 first.</p>
2552
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2553<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2554 documented here. Constraints on what can be done (e.g. duplication, moving,
2555 etc need to be documented). This is probably best done by reference to
2556 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2557</div>
2558
2559<div class="doc_subsubsection">
2560<a name="inlineasm_md">Inline Asm Metadata</a>
2561</div>
2562
2563<div class="doc_text">
2564
2565<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
2566 attached to it that contains a constant integer. If present, the code
2567 generator will use the integer as the location cookie value when report
2568 errors through the LLVMContext error reporting mechanisms. This allows a
2569 front-end to corrolate backend errors that occur with inline asm back to the
2570 source code that produced it. For example:</p>
2571
2572<div class="doc_code">
2573<pre>
2574call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2575...
2576!42 = !{ i32 1234567 }
2577</pre>
2578</div>
2579
2580<p>It is up to the front-end to make sense of the magic numbers it places in the
2581 IR.</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2582
2583</div>
2584
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2585<!-- ======================================================================= -->
2586<div class="doc_subsection"><a name="metadata">Metadata Nodes and Metadata
2587 Strings</a>
2588</div>
2589
2590<div class="doc_text">
2591
2592<p>LLVM IR allows metadata to be attached to instructions in the program that
2593 can convey extra information about the code to the optimizers and code
2594 generator. One example application of metadata is source-level debug
2595 information. There are two metadata primitives: strings and nodes. All
2596 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2597 preceding exclamation point ('<tt>!</tt>').</p>
2598
2599<p>A metadata string is a string surrounded by double quotes. It can contain
2600 any character by escaping non-printable characters with "\xx" where "xx" is
2601 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2602
2603<p>Metadata nodes are represented with notation similar to structure constants
2604 (a comma separated list of elements, surrounded by braces and preceded by an
2605 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2606 10}</tt>". Metadata nodes can have any values as their operand.</p>
2607
2608<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2609 metadata nodes, which can be looked up in the module symbol table. For
2610 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2611
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2612<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
2613 function is using two metadata arguments.
2614
2615 <div class="doc_code">
2616 <pre>
2617 call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2618 </pre>
2619 </div></p>
2620
2621<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
2622 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.
2623
2624 <div class="doc_code">
2625 <pre>
2626 %indvar.next = add i64 %indvar, 1, !dbg !21
2627 </pre>
2628 </div></p>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2629</div>
2630
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2631
2632<!-- *********************************************************************** -->
2633<div class="doc_section">
2634 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2635</div>
2636<!-- *********************************************************************** -->
2637
2638<p>LLVM has a number of "magic" global variables that contain data that affect
2639code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2640of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2641section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2642by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2643
2644<!-- ======================================================================= -->
2645<div class="doc_subsection">
2646<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2647</div>
2648
2649<div class="doc_text">
2650
2651<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2652href="#linkage_appending">appending linkage</a>. This array contains a list of
2653pointers to global variables and functions which may optionally have a pointer
2654cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2655
2656<pre>
2657 @X = global i8 4
2658 @Y = global i32 123
2659
2660 @llvm.used = appending global [2 x i8*] [
2661 i8* @X,
2662 i8* bitcast (i32* @Y to i8*)
2663 ], section "llvm.metadata"
2664</pre>
2665
2666<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2667compiler, assembler, and linker are required to treat the symbol as if there is
2668a reference to the global that it cannot see. For example, if a variable has
2669internal linkage and no references other than that from the <tt>@llvm.used</tt>
2670list, it cannot be deleted. This is commonly used to represent references from
2671inline asms and other things the compiler cannot "see", and corresponds to
2672"attribute((used))" in GNU C.</p>
2673
2674<p>On some targets, the code generator must emit a directive to the assembler or
2675object file to prevent the assembler and linker from molesting the symbol.</p>
2676
2677</div>
2678
2679<!-- ======================================================================= -->
2680<div class="doc_subsection">
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2681<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2682</div>
2683
2684<div class="doc_text">
2685
2686<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2687<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2688touching the symbol. On targets that support it, this allows an intelligent
2689linker to optimize references to the symbol without being impeded as it would be
2690by <tt>@llvm.used</tt>.</p>
2691
2692<p>This is a rare construct that should only be used in rare circumstances, and
2693should not be exposed to source languages.</p>
2694
2695</div>
2696
2697<!-- ======================================================================= -->
2698<div class="doc_subsection">
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2699<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2700</div>
2701
2702<div class="doc_text">
2703
2704<p>TODO: Describe this.</p>
2705
2706</div>
2707
2708<!-- ======================================================================= -->
2709<div class="doc_subsection">
2710<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2711</div>
2712
2713<div class="doc_text">
2714
2715<p>TODO: Describe this.</p>
2716
2717</div>
2718
2719
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2720<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2721<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2722<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2723
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2724<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2725
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2726<p>The LLVM instruction set consists of several different classifications of
2727 instructions: <a href="#terminators">terminator
2728 instructions</a>, <a href="#binaryops">binary instructions</a>,
2729 <a href="#bitwiseops">bitwise binary instructions</a>,
2730 <a href="#memoryops">memory instructions</a>, and
2731 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2732
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2733</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2734
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2735<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2736<div class="doc_subsection"> <a name="terminators">Terminator
2737Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2738
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2739<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2740
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2741<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2742 in a program ends with a "Terminator" instruction, which indicates which
2743 block should be executed after the current block is finished. These
2744 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2745 control flow, not values (the one exception being the
2746 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2747
Duncan Sands83821c82010-04-15 20:35:54 +0000[diff] [blame]2748<p>There are seven different terminator instructions: the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2749 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2750 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2751 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling21c346e2009-11-02 00:25:26 +0000[diff] [blame]2752 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2753 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2754 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2755 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2756
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2757</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2758
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2759<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2760<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2761Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2762
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2763<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2764
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2765<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2766<pre>
2767 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]2768 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2769</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2770
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2771<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2772<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2773 a value) from a function back to the caller.</p>
2774
2775<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2776 value and then causes control flow, and one that just causes control flow to
2777 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2778
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2779<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2780<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2781 return value. The type of the return value must be a
2782 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2783
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2784<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2785 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2786 value or a return value with a type that does not match its type, or if it
2787 has a void return type and contains a '<tt>ret</tt>' instruction with a
2788 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2789
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2790<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2791<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2792 the calling function's context. If the caller is a
2793 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2794 instruction after the call. If the caller was an
2795 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2796 the beginning of the "normal" destination block. If the instruction returns
2797 a value, that value shall set the call or invoke instruction's return
2798 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2799
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2800<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2801<pre>
2802 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2803 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]2804 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]2805</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2806
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2807</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2808<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2809<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2810
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2811<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2812
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2813<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2814<pre>
2815 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]2816</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2817
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2818<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2819<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2820 different basic block in the current function. There are two forms of this
2821 instruction, corresponding to a conditional branch and an unconditional
2822 branch.</p>
2823
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2824<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2825<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2826 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2827 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2828 target.</p>
2829
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2830<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2831<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2832 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2833 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2834 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2835
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2836<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2837<pre>
2838Test:
2839 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2840 br i1 %cond, label %IfEqual, label %IfUnequal
2841IfEqual:
2842 <a href="#i_ret">ret</a> i32 1
2843IfUnequal:
2844 <a href="#i_ret">ret</a> i32 0
2845</pre>
2846
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2847</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2848
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2849<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2850<div class="doc_subsubsection">
2851 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2852</div>
2853
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2854<div class="doc_text">
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2855
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2856<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2857<pre>
2858 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2859</pre>
2860
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2861<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2862<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]2863 several different places. It is a generalization of the '<tt>br</tt>'
2864 instruction, allowing a branch to occur to one of many possible
2865 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2866
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2867<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2868<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2869 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2870 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2871 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2872
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2873<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2874<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2875 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2876 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]2877 transferred to the corresponding destination; otherwise, control flow is
2878 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2879
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2880<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2881<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2882 <tt>switch</tt> instruction, this instruction may be code generated in
2883 different ways. For example, it could be generated as a series of chained
2884 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2885
2886<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2887<pre>
2888 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2889 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2890 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2891
2892 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2893 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2894
2895 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2896 switch i32 %val, label %otherwise [ i32 0, label %onzero
2897 i32 1, label %onone
2898 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2899</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2900
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2901</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2902
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2903
2904<!-- _______________________________________________________________________ -->
2905<div class="doc_subsubsection">
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2906 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2907</div>
2908
2909<div class="doc_text">
2910
2911<h5>Syntax:</h5>
2912<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2913 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]2914</pre>
2915
2916<h5>Overview:</h5>
2917
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2918<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2919 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2920 "<tt>address</tt>". Address must be derived from a <a
2921 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2922
2923<h5>Arguments:</h5>
2924
2925<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
2926 rest of the arguments indicate the full set of possible destinations that the
2927 address may point to. Blocks are allowed to occur multiple times in the
2928 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2929
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2930<p>This destination list is required so that dataflow analysis has an accurate
2931 understanding of the CFG.</p>
2932
2933<h5>Semantics:</h5>
2934
2935<p>Control transfers to the block specified in the address argument. All
2936 possible destination blocks must be listed in the label list, otherwise this
2937 instruction has undefined behavior. This implies that jumps to labels
2938 defined in other functions have undefined behavior as well.</p>
2939
2940<h5>Implementation:</h5>
2941
2942<p>This is typically implemented with a jump through a register.</p>
2943
2944<h5>Example:</h5>
2945<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2946 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2947</pre>
2948
2949</div>
2950
2951
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2952<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2953<div class="doc_subsubsection">
2954 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2955</div>
2956
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2957<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2958
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2959<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2960<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2961 &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]2962 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2963</pre>
2964
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2965<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2966<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2967 function, with the possibility of control flow transfer to either the
2968 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2969 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2970 control flow will return to the "normal" label. If the callee (or any
2971 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2972 instruction, control is interrupted and continued at the dynamically nearest
2973 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2974
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2975<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2976<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2977
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2978<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2979 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2980 convention</a> the call should use. If none is specified, the call
2981 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2982
2983 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2984 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2985 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2986
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2987 <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]2988 function value being invoked. In most cases, this is a direct function
2989 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2990 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2991
2992 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2993 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2994
2995 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]2996 signature argument types and parameter attributes. All arguments must be
2997 of <a href="#t_firstclass">first class</a> type. If the function
2998 signature indicates the function accepts a variable number of arguments,
2999 the extra arguments can be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3000
3001 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3002 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3003
3004 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3005 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3006
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3007 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3008 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3009 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3010</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3011
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3012<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3013<p>This instruction is designed to operate as a standard
3014 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3015 primary difference is that it establishes an association with a label, which
3016 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3017
3018<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3019 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3020 exception. Additionally, this is important for implementation of
3021 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3022
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3023<p>For the purposes of the SSA form, the definition of the value returned by the
3024 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3025 block to the "normal" label. If the callee unwinds then no return value is
3026 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]3027
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3028<p>Note that the code generator does not yet completely support unwind, and
3029that the invoke/unwind semantics are likely to change in future versions.</p>
3030
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3031<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3032<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3033 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3034 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3035 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3036 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3037</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3038
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3039</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3040
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3041<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3042
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3043<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
3044Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3045
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3046<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3047
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3048<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3049<pre>
3050 unwind
3051</pre>
3052
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3053<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3054<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3055 at the first callee in the dynamic call stack which used
3056 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3057 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3058
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3059<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3060<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3061 immediately halt. The dynamic call stack is then searched for the
3062 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3063 Once found, execution continues at the "exceptional" destination block
3064 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3065 instruction in the dynamic call chain, undefined behavior results.</p>
3066
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3067<p>Note that the code generator does not yet completely support unwind, and
3068that the invoke/unwind semantics are likely to change in future versions.</p>
3069
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3070</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3071
3072<!-- _______________________________________________________________________ -->
3073
3074<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
3075Instruction</a> </div>
3076
3077<div class="doc_text">
3078
3079<h5>Syntax:</h5>
3080<pre>
3081 unreachable
3082</pre>
3083
3084<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3085<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3086 instruction is used to inform the optimizer that a particular portion of the
3087 code is not reachable. This can be used to indicate that the code after a
3088 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3089
3090<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3091<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3092
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3093</div>
3094
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3095<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3096<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3097
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3098<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3099
3100<p>Binary operators are used to do most of the computation in a program. They
3101 require two operands of the same type, execute an operation on them, and
3102 produce a single value. The operands might represent multiple data, as is
3103 the case with the <a href="#t_vector">vector</a> data type. The result value
3104 has the same type as its operands.</p>
3105
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3106<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3107
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3108</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3109
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3110<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3111<div class="doc_subsubsection">
3112 <a name="i_add">'<tt>add</tt>' Instruction</a>
3113</div>
3114
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3115<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3116
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3117<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3118<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3119 &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]3120 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3121 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3122 &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]3123</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3124
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3125<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3126<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3127
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3128<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3129<p>The two arguments to the '<tt>add</tt>' instruction must
3130 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3131 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3132
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3133<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3134<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3135
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3136<p>If the sum has unsigned overflow, the result returned is the mathematical
3137 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]3138
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3139<p>Because LLVM integers use a two's complement representation, this instruction
3140 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3141
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3142<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3143 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3144 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3145 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3146 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3147
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3148<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3149<pre>
3150 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3151</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3152
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3153</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3154
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3155<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3156<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3157 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
3158</div>
3159
3160<div class="doc_text">
3161
3162<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3163<pre>
3164 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3165</pre>
3166
3167<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3168<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3169
3170<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3171<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3172 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3173 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3174
3175<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3176<p>The value produced is the floating point sum of the two operands.</p>
3177
3178<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3179<pre>
3180 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3181</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3182
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3183</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3184
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3185<!-- _______________________________________________________________________ -->
3186<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3187 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
3188</div>
3189
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3190<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3191
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3192<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3193<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3194 &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]3195 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3196 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3197 &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]3198</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3199
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3200<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3201<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3202 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3203
3204<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3205 '<tt>neg</tt>' instruction present in most other intermediate
3206 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3207
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3208<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3209<p>The two arguments to the '<tt>sub</tt>' instruction must
3210 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3211 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3212
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3213<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3214<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3215
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3216<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3217 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3218 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3219
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3220<p>Because LLVM integers use a two's complement representation, this instruction
3221 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3222
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3223<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3224 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3225 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3226 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3227 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3228
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3229<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3230<pre>
3231 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3232 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3233</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3234
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3235</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3236
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3237<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3238<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3239 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
3240</div>
3241
3242<div class="doc_text">
3243
3244<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3245<pre>
3246 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3247</pre>
3248
3249<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3250<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3251 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3252
3253<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3254 '<tt>fneg</tt>' instruction present in most other intermediate
3255 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3256
3257<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3258<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3259 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3260 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3261
3262<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3263<p>The value produced is the floating point difference of the two operands.</p>
3264
3265<h5>Example:</h5>
3266<pre>
3267 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3268 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3269</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3270
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3271</div>
3272
3273<!-- _______________________________________________________________________ -->
3274<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3275 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
3276</div>
3277
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3278<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3279
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3280<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3281<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3282 &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]3283 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3284 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3285 &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]3286</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3287
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3288<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3289<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3290
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3291<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3292<p>The two arguments to the '<tt>mul</tt>' instruction must
3293 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3294 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3295
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3296<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3297<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3298
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3299<p>If the result of the multiplication has unsigned overflow, the result
3300 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3301 width of the result.</p>
3302
3303<p>Because LLVM integers use a two's complement representation, and the result
3304 is the same width as the operands, this instruction returns the correct
3305 result for both signed and unsigned integers. If a full product
3306 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3307 be sign-extended or zero-extended as appropriate to the width of the full
3308 product.</p>
3309
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3310<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3311 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3312 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3313 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3314 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3315
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3316<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3317<pre>
3318 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3319</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3320
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3321</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3322
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3323<!-- _______________________________________________________________________ -->
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3324<div class="doc_subsubsection">
3325 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
3326</div>
3327
3328<div class="doc_text">
3329
3330<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3331<pre>
3332 &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]3333</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3334
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3335<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3336<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3337
3338<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3339<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3340 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3341 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3342
3343<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3344<p>The value produced is the floating point product of the two operands.</p>
3345
3346<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3347<pre>
3348 &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]3349</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3350
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3351</div>
3352
3353<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3354<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
3355</a></div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3356
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3357<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3358
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3359<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3360<pre>
3361 &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]3362</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3363
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3364<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3365<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3366
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3367<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3368<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3369 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3370 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3371
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3372<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3373<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3374
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3375<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3376 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3377
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3378<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3379
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3380<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3381<pre>
3382 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3383</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3384
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3385</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3386
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3387<!-- _______________________________________________________________________ -->
3388<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
3389</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3390
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3391<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3392
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3393<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3394<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3395 &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]3396 &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]3397</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3398
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3399<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3400<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3401
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3402<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3403<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3404 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3405 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3406
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3407<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3408<p>The value produced is the signed integer quotient of the two operands rounded
3409 towards zero.</p>
3410
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3411<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3412 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3413
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3414<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3415 undefined behavior; this is a rare case, but can occur, for example, by doing
3416 a 32-bit division of -2147483648 by -1.</p>
3417
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3418<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]3419 <tt>sdiv</tt> is a <a href="#trapvalues">trap value</a> if the result would
3420 be rounded or if overflow would occur.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3421
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3422<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3423<pre>
3424 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3425</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3426
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3427</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3428
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3429<!-- _______________________________________________________________________ -->
3430<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3431Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3432
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3433<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3434
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3435<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3436<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3437 &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]3438</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3439
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3440<h5>Overview:</h5>
3441<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3442
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3443<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3444<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3445 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3446 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3447
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3448<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3449<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3450
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3451<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3452<pre>
3453 &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]3454</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3455
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3456</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3457
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3458<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3459<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3460</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3461
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3462<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3463
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3464<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3465<pre>
3466 &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]3467</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3468
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3469<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3470<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3471 division of its two arguments.</p>
3472
Reid Spencer0a783f72006-11-02 01:53:59 +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>urem</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>
3477
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3478<h5>Semantics:</h5>
3479<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3480 This instruction always performs an unsigned division to get the
3481 remainder.</p>
3482
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3483<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3484 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3485
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3486<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3487
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3488<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3489<pre>
3490 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3491</pre>
3492
3493</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3494
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3495<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3496<div class="doc_subsubsection">
3497 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3498</div>
3499
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3500<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3501
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3502<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3503<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3504 &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]3505</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3506
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3507<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3508<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3509 division of its two operands. This instruction can also take
3510 <a href="#t_vector">vector</a> versions of the values in which case the
3511 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3512
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3513<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3514<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3515 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3516 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3517
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3518<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3519<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3520 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3521 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3522 a value. For more information about the difference,
3523 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3524 Math Forum</a>. For a table of how this is implemented in various languages,
3525 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3526 Wikipedia: modulo operation</a>.</p>
3527
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3528<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3529 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3530
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3531<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3532 Overflow also leads to undefined behavior; this is a rare case, but can
3533 occur, for example, by taking the remainder of a 32-bit division of
3534 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3535 lets srem be implemented using instructions that return both the result of
3536 the division and the remainder.)</p>
3537
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3538<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3539<pre>
3540 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3541</pre>
3542
3543</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3544
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3545<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3546<div class="doc_subsubsection">
3547 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3548
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3549<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3550
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3551<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3552<pre>
3553 &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]3554</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3555
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3556<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3557<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3558 its two operands.</p>
3559
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3560<h5>Arguments:</h5>
3561<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3562 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3563 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3564
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3565<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3566<p>This instruction returns the <i>remainder</i> of a division. The remainder
3567 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3568
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3569<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3570<pre>
3571 &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]3572</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3573
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3574</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3575
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3576<!-- ======================================================================= -->
3577<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3578Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3579
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3580<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3581
3582<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3583 program. They are generally very efficient instructions and can commonly be
3584 strength reduced from other instructions. They require two operands of the
3585 same type, execute an operation on them, and produce a single value. The
3586 resulting value is the same type as its operands.</p>
3587
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3588</div>
3589
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3590<!-- _______________________________________________________________________ -->
3591<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3592Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3593
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3594<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3595
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3596<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3597<pre>
3598 &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]3599</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3600
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3601<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3602<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3603 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3604
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3605<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3606<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3607 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3608 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3609
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3610<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3611<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3612 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3613 is (statically or dynamically) negative or equal to or larger than the number
3614 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3615 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3616 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3617
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3618<h5>Example:</h5>
3619<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3620 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3621 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3622 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3623 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3624 &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]3625</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3626
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3627</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3628
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3629<!-- _______________________________________________________________________ -->
3630<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3631Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3632
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3633<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3634
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3635<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3636<pre>
3637 &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]3638</pre>
3639
3640<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3641<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3642 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3643
3644<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3645<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3646 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3647 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3648
3649<h5>Semantics:</h5>
3650<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3651 significant bits of the result will be filled with zero bits after the shift.
3652 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3653 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3654 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3655 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3656
3657<h5>Example:</h5>
3658<pre>
3659 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3660 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3661 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3662 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3663 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3664 &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]3665</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3666
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3667</div>
3668
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3669<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3670<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3671Instruction</a> </div>
3672<div class="doc_text">
3673
3674<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3675<pre>
3676 &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]3677</pre>
3678
3679<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3680<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3681 operand shifted to the right a specified number of bits with sign
3682 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3683
3684<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3685<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3686 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3687 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3688
3689<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3690<p>This instruction always performs an arithmetic shift right operation, The
3691 most significant bits of the result will be filled with the sign bit
3692 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3693 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3694 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3695 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3696
3697<h5>Example:</h5>
3698<pre>
3699 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3700 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3701 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3702 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3703 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3704 &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]3705</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3706
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3707</div>
3708
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3709<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3710<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3711Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3712
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3713<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3714
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3715<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3716<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3717 &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]3718</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3719
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3720<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3721<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3722 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3723
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3724<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3725<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3726 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3727 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3728
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3729<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3730<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3731
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3732<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3733 <tbody>
3734 <tr>
3735 <td>In0</td>
3736 <td>In1</td>
3737 <td>Out</td>
3738 </tr>
3739 <tr>
3740 <td>0</td>
3741 <td>0</td>
3742 <td>0</td>
3743 </tr>
3744 <tr>
3745 <td>0</td>
3746 <td>1</td>
3747 <td>0</td>
3748 </tr>
3749 <tr>
3750 <td>1</td>
3751 <td>0</td>
3752 <td>0</td>
3753 </tr>
3754 <tr>
3755 <td>1</td>
3756 <td>1</td>
3757 <td>1</td>
3758 </tr>
3759 </tbody>
3760</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3761
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3762<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3763<pre>
3764 &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]3765 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3766 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3767</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3768</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3769<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3770<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3771
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3772<div class="doc_text">
3773
3774<h5>Syntax:</h5>
3775<pre>
3776 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3777</pre>
3778
3779<h5>Overview:</h5>
3780<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3781 two operands.</p>
3782
3783<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3784<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3785 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3786 values. Both arguments must have identical types.</p>
3787
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3788<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3789<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3790
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3791<table border="1" cellspacing="0" cellpadding="4">
3792 <tbody>
3793 <tr>
3794 <td>In0</td>
3795 <td>In1</td>
3796 <td>Out</td>
3797 </tr>
3798 <tr>
3799 <td>0</td>
3800 <td>0</td>
3801 <td>0</td>
3802 </tr>
3803 <tr>
3804 <td>0</td>
3805 <td>1</td>
3806 <td>1</td>
3807 </tr>
3808 <tr>
3809 <td>1</td>
3810 <td>0</td>
3811 <td>1</td>
3812 </tr>
3813 <tr>
3814 <td>1</td>
3815 <td>1</td>
3816 <td>1</td>
3817 </tr>
3818 </tbody>
3819</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3820
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3821<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3822<pre>
3823 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3824 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3825 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3826</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3827
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3828</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3829
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3830<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3831<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3832Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3833
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3834<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3835
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3836<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3837<pre>
3838 &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]3839</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3840
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3841<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3842<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3843 its two operands. The <tt>xor</tt> is used to implement the "one's
3844 complement" operation, which is the "~" operator in C.</p>
3845
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3846<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3847<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3848 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3849 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3850
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3851<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3852<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3853
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3854<table border="1" cellspacing="0" cellpadding="4">
3855 <tbody>
3856 <tr>
3857 <td>In0</td>
3858 <td>In1</td>
3859 <td>Out</td>
3860 </tr>
3861 <tr>
3862 <td>0</td>
3863 <td>0</td>
3864 <td>0</td>
3865 </tr>
3866 <tr>
3867 <td>0</td>
3868 <td>1</td>
3869 <td>1</td>
3870 </tr>
3871 <tr>
3872 <td>1</td>
3873 <td>0</td>
3874 <td>1</td>
3875 </tr>
3876 <tr>
3877 <td>1</td>
3878 <td>1</td>
3879 <td>0</td>
3880 </tr>
3881 </tbody>
3882</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3883
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3884<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3885<pre>
3886 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3887 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3888 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3889 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3890</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3891
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3892</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3893
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3894<!-- ======================================================================= -->
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3895<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3896 <a name="vectorops">Vector Operations</a>
3897</div>
3898
3899<div class="doc_text">
3900
3901<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3902 target-independent manner. These instructions cover the element-access and
3903 vector-specific operations needed to process vectors effectively. While LLVM
3904 does directly support these vector operations, many sophisticated algorithms
3905 will want to use target-specific intrinsics to take full advantage of a
3906 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3907
3908</div>
3909
3910<!-- _______________________________________________________________________ -->
3911<div class="doc_subsubsection">
3912 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3913</div>
3914
3915<div class="doc_text">
3916
3917<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3918<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3919 &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]3920</pre>
3921
3922<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3923<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3924 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3925
3926
3927<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3928<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3929 of <a href="#t_vector">vector</a> type. The second operand is an index
3930 indicating the position from which to extract the element. The index may be
3931 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3932
3933<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3934<p>The result is a scalar of the same type as the element type of
3935 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3936 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3937 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3938
3939<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3940<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]3941 &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]3942</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3943
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3944</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3945
3946<!-- _______________________________________________________________________ -->
3947<div class="doc_subsubsection">
3948 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3949</div>
3950
3951<div class="doc_text">
3952
3953<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3954<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]3955 &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]3956</pre>
3957
3958<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3959<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3960 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3961
3962<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3963<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3964 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3965 whose type must equal the element type of the first operand. The third
3966 operand is an index indicating the position at which to insert the value.
3967 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3968
3969<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3970<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3971 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3972 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3973 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3974
3975<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3976<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]3977 &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]3978</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3979
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3980</div>
3981
3982<!-- _______________________________________________________________________ -->
3983<div class="doc_subsubsection">
3984 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3985</div>
3986
3987<div class="doc_text">
3988
3989<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3990<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3991 &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]3992</pre>
3993
3994<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3995<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3996 from two input vectors, returning a vector with the same element type as the
3997 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3998
3999<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4000<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4001 with types that match each other. The third argument is a shuffle mask whose
4002 element type is always 'i32'. The result of the instruction is a vector
4003 whose length is the same as the shuffle mask and whose element type is the
4004 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4005
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4006<p>The shuffle mask operand is required to be a constant vector with either
4007 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4008
4009<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4010<p>The elements of the two input vectors are numbered from left to right across
4011 both of the vectors. The shuffle mask operand specifies, for each element of
4012 the result vector, which element of the two input vectors the result element
4013 gets. The element selector may be undef (meaning "don't care") and the
4014 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4015
4016<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4017<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4018 &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]4019 &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]4020 &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]4021 &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]4022 &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]4023 &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]4024 &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]4025 &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]4026</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4027
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4028</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]4029
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4030<!-- ======================================================================= -->
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4031<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4032 <a name="aggregateops">Aggregate Operations</a>
4033</div>
4034
4035<div class="doc_text">
4036
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4037<p>LLVM supports several instructions for working with
4038 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4039
4040</div>
4041
4042<!-- _______________________________________________________________________ -->
4043<div class="doc_subsubsection">
4044 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
4045</div>
4046
4047<div class="doc_text">
4048
4049<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4050<pre>
4051 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4052</pre>
4053
4054<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4055<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4056 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4057
4058<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4059<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4060 of <a href="#t_struct">struct</a>, <a href="#t_union">union</a> or
4061 <a href="#t_array">array</a> type. The operands are constant indices to
4062 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4063 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4064
4065<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4066<p>The result is the value at the position in the aggregate specified by the
4067 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4068
4069<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4070<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4071 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4072</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4073
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4074</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4075
4076<!-- _______________________________________________________________________ -->
4077<div class="doc_subsubsection">
4078 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
4079</div>
4080
4081<div class="doc_text">
4082
4083<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4084<pre>
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]4085 &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]4086</pre>
4087
4088<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4089<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4090 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4091
4092<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4093<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4094 of <a href="#t_struct">struct</a>, <a href="#t_union">union</a> or
4095 <a href="#t_array">array</a> type. The second operand is a first-class
4096 value to insert. The following operands are constant indices indicating
4097 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]4098 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
4099 value to insert must have the same type as the value identified by the
4100 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4101
4102<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4103<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4104 that of <tt>val</tt> except that the value at the position specified by the
4105 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4106
4107<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4108<pre>
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]4109 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4110 %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]4111</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4112
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4113</div>
4114
4115
4116<!-- ======================================================================= -->
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4117<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4118 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4119</div>
4120
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4121<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4122
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4123<p>A key design point of an SSA-based representation is how it represents
4124 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4125 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4126 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4127
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4128</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4129
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4130<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4131<div class="doc_subsubsection">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4132 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
4133</div>
4134
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4135<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4136
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4137<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4138<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4139 &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]4140</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4141
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4142<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4143<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4144 currently executing function, to be automatically released when this function
4145 returns to its caller. The object is always allocated in the generic address
4146 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4147
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4148<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4149<p>The '<tt>alloca</tt>' instruction
4150 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4151 runtime stack, returning a pointer of the appropriate type to the program.
4152 If "NumElements" is specified, it is the number of elements allocated,
4153 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4154 specified, the value result of the allocation is guaranteed to be aligned to
4155 at least that boundary. If not specified, or if zero, the target can choose
4156 to align the allocation on any convenient boundary compatible with the
4157 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4158
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4159<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4160
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4161<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4162<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4163 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4164 memory is automatically released when the function returns. The
4165 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4166 variables that must have an address available. When the function returns
4167 (either with the <tt><a href="#i_ret">ret</a></tt>
4168 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4169 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4170
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4171<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4172<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4173 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4174 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4175 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4176 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4177</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4178
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4179</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4180
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4181<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4182<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
4183Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4184
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4185<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4186
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4187<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4188<pre>
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4189 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4190 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4191 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4192</pre>
4193
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4194<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4195<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4196
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4197<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4198<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4199 from which to load. The pointer must point to
4200 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4201 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
4202 number or order of execution of this <tt>load</tt> with other
4203 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4204 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4205
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4206<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4207 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]4208 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4209 alignment for the target. It is the responsibility of the code emitter to
4210 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4211 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4212 produce less efficient code. An alignment of 1 is always safe.</p>
4213
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4214<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4215 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4216 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4217 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4218 and code generator that this load is not expected to be reused in the cache.
4219 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4220 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4221
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4222<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4223<p>The location of memory pointed to is loaded. If the value being loaded is of
4224 scalar type then the number of bytes read does not exceed the minimum number
4225 of bytes needed to hold all bits of the type. For example, loading an
4226 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4227 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4228 is undefined if the value was not originally written using a store of the
4229 same type.</p>
4230
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4231<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4232<pre>
4233 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4234 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4235 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4236</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4237
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4238</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4239
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4240<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4241<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
4242Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4243
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]4244<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4245
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4246<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4247<pre>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4248 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>] <i>; yields {void}</i>
4249 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]4250</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4251
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4252<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4253<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4254
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4255<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4256<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4257 and an address at which to store it. The type of the
4258 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4259 the <a href="#t_firstclass">first class</a> type of the
4260 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
4261 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
4262 or order of execution of this <tt>store</tt> with other
4263 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
4264 instructions.</p>
4265
4266<p>The optional constant "align" argument specifies the alignment of the
4267 operation (that is, the alignment of the memory address). A value of 0 or an
4268 omitted "align" argument means that the operation has the preferential
4269 alignment for the target. It is the responsibility of the code emitter to
4270 ensure that the alignment information is correct. Overestimating the
4271 alignment results in an undefined behavior. Underestimating the alignment may
4272 produce less efficient code. An alignment of 1 is always safe.</p>
4273
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4274<p>The optional !nontemporal metadata must reference a single metatadata
4275 name <index> corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4276 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4277 instruction tells the optimizer and code generator that this load is
4278 not expected to be reused in the cache. The code generator may
4279 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4280 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4281
4282
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4283<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4284<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4285 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4286 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4287 does not exceed the minimum number of bytes needed to hold all bits of the
4288 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4289 writing a value of a type like <tt>i20</tt> with a size that is not an
4290 integral number of bytes, it is unspecified what happens to the extra bits
4291 that do not belong to the type, but they will typically be overwritten.</p>
4292
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4293<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4294<pre>
4295 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4296 store i32 3, i32* %ptr <i>; yields {void}</i>
4297 %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]4298</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4299
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4300</div>
4301
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4302<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4303<div class="doc_subsubsection">
4304 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
4305</div>
4306
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4307<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4308
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4309<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4310<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4311 &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]4312 &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]4313</pre>
4314
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4315<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4316<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4317 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4318 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4319
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4320<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4321<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4322 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4323 elements of the aggregate object are indexed. The interpretation of each
4324 index is dependent on the type being indexed into. The first index always
4325 indexes the pointer value given as the first argument, the second index
4326 indexes a value of the type pointed to (not necessarily the value directly
4327 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4328 indexed into must be a pointer value, subsequent types can be arrays,
4329 vectors, structs and unions. Note that subsequent types being indexed into
4330 can never be pointers, since that would require loading the pointer before
4331 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4332
4333<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]4334 When indexing into a (optionally packed) structure or union, only <tt>i32</tt>
4335 integer <b>constants</b> are allowed. When indexing into an array, pointer
4336 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]4337 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4338
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4339<p>For example, let's consider a C code fragment and how it gets compiled to
4340 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4341
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4342<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4343<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4344struct RT {
4345 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4346 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4347 char C;
4348};
4349struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4350 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4351 double Y;
4352 struct RT Z;
4353};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4354
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4355int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4356 return &amp;s[1].Z.B[5][13];
4357}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4358</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4359</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4360
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4361<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4362
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4363<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4364<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]4365%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4366%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4367
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4368define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4369entry:
4370 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4371 ret i32* %reg
4372}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4373</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4374</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4375
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4376<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4377<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]4378 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4379 }</tt>' type, a structure. The second index indexes into the third element
4380 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4381 i8 }</tt>' type, another structure. The third index indexes into the second
4382 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4383 array. The two dimensions of the array are subscripted into, yielding an
4384 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4385 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4386
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4387<p>Note that it is perfectly legal to index partially through a structure,
4388 returning a pointer to an inner element. Because of this, the LLVM code for
4389 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4390
4391<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4392 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4393 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4394 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4395 %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]4396 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4397 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4398 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4399 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4400</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]4401
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4402<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]4403 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4404 base pointer is not an <i>in bounds</i> address of an allocated object,
4405 or if any of the addresses that would be formed by successive addition of
4406 the offsets implied by the indices to the base address with infinitely
4407 precise arithmetic are not an <i>in bounds</i> address of that allocated
4408 object. The <i>in bounds</i> addresses for an allocated object are all
4409 the addresses that point into the object, plus the address one byte past
4410 the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4411
4412<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4413 the base address with silently-wrapping two's complement arithmetic, and
4414 the result value of the <tt>getelementptr</tt> may be outside the object
4415 pointed to by the base pointer. The result value may not necessarily be
4416 used to access memory though, even if it happens to point into allocated
4417 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4418 section for more information.</p>
4419
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4420<p>The getelementptr instruction is often confusing. For some more insight into
4421 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4422
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4423<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4424<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4425 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4426 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4427 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4428 %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]4429 <i>; yields i8*:eptr</i>
4430 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]4431 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]4432 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4433</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4434
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4435</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4436
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4437<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4438<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4439</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4440
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4441<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4442
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4443<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4444 which all take a single operand and a type. They perform various bit
4445 conversions on the operand.</p>
4446
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4447</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4448
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4449<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4450<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4451 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4452</div>
4453<div class="doc_text">
4454
4455<h5>Syntax:</h5>
4456<pre>
4457 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4458</pre>
4459
4460<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4461<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4462 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4463
4464<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4465<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4466 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4467 size and type of the result, which must be
4468 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4469 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4470 allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4471
4472<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4473<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4474 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4475 source size must be larger than the destination size, <tt>trunc</tt> cannot
4476 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4477
4478<h5>Example:</h5>
4479<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4480 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4481 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4482 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4483</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4484
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4485</div>
4486
4487<!-- _______________________________________________________________________ -->
4488<div class="doc_subsubsection">
4489 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4490</div>
4491<div class="doc_text">
4492
4493<h5>Syntax:</h5>
4494<pre>
4495 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4496</pre>
4497
4498<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4499<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4500 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4501
4502
4503<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4504<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]4505 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4506 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]4507 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4508 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4509
4510<h5>Semantics:</h5>
4511<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]4512 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4513
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]4514<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]4515
4516<h5>Example:</h5>
4517<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4518 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4519 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4520</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4521
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4522</div>
4523
4524<!-- _______________________________________________________________________ -->
4525<div class="doc_subsubsection">
4526 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4527</div>
4528<div class="doc_text">
4529
4530<h5>Syntax:</h5>
4531<pre>
4532 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4533</pre>
4534
4535<h5>Overview:</h5>
4536<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4537
4538<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4539<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]4540 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4541 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]4542 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4543 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4544
4545<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4546<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4547 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4548 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4549
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4550<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]4551
4552<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4553<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4554 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4555 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4556</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4557
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4558</div>
4559
4560<!-- _______________________________________________________________________ -->
4561<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4562 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4563</div>
4564
4565<div class="doc_text">
4566
4567<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4568<pre>
4569 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4570</pre>
4571
4572<h5>Overview:</h5>
4573<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4574 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4575
4576<h5>Arguments:</h5>
4577<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4578 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4579 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]4580 <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]4581 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4582
4583<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4584<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4585 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4586 <a href="#t_floating">floating point</a> type. If the value cannot fit
4587 within the destination type, <tt>ty2</tt>, then the results are
4588 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4589
4590<h5>Example:</h5>
4591<pre>
4592 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4593 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4594</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4595
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4596</div>
4597
4598<!-- _______________________________________________________________________ -->
4599<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4600 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4601</div>
4602<div class="doc_text">
4603
4604<h5>Syntax:</h5>
4605<pre>
4606 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4607</pre>
4608
4609<h5>Overview:</h5>
4610<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]4611 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4612
4613<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4614<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4615 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4616 a <a href="#t_floating">floating point</a> type to cast it to. The source
4617 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4618
4619<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4620<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4621 <a href="#t_floating">floating point</a> type to a larger
4622 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4623 used to make a <i>no-op cast</i> because it always changes bits. Use
4624 <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]4625
4626<h5>Example:</h5>
4627<pre>
4628 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4629 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4630</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4631
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4632</div>
4633
4634<!-- _______________________________________________________________________ -->
4635<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]4636 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4637</div>
4638<div class="doc_text">
4639
4640<h5>Syntax:</h5>
4641<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4642 &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]4643</pre>
4644
4645<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4646<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4647 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4648
4649<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4650<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4651 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4652 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4653 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4654 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4655
4656<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4657<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4658 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4659 towards zero) unsigned integer value. If the value cannot fit
4660 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4661
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4662<h5>Example:</h5>
4663<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4664 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4665 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4666 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4667</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4668
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4669</div>
4670
4671<!-- _______________________________________________________________________ -->
4672<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4673 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4674</div>
4675<div class="doc_text">
4676
4677<h5>Syntax:</h5>
4678<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4679 &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]4680</pre>
4681
4682<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4683<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4684 <a href="#t_floating">floating point</a> <tt>value</tt> to
4685 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4686
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4687<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4688<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4689 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4690 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4691 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4692 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4693
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4694<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4695<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4696 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4697 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4698 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4699
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4700<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4701<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4702 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4703 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4704 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4705</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4706
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4707</div>
4708
4709<!-- _______________________________________________________________________ -->
4710<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4711 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4712</div>
4713<div class="doc_text">
4714
4715<h5>Syntax:</h5>
4716<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4717 &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]4718</pre>
4719
4720<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4721<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4722 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4723
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4724<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4725<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]4726 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4727 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4728 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4729 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4730
4731<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4732<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4733 integer quantity and converts it to the corresponding floating point
4734 value. If the value cannot fit in the floating point value, the results are
4735 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4736
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4737<h5>Example:</h5>
4738<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4739 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4740 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4741</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4742
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4743</div>
4744
4745<!-- _______________________________________________________________________ -->
4746<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4747 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4748</div>
4749<div class="doc_text">
4750
4751<h5>Syntax:</h5>
4752<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4753 &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]4754</pre>
4755
4756<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4757<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4758 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4759
4760<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4761<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]4762 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4763 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4764 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4765 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4766
4767<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4768<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4769 quantity and converts it to the corresponding floating point value. If the
4770 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4771
4772<h5>Example:</h5>
4773<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4774 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4775 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4776</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4777
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4778</div>
4779
4780<!-- _______________________________________________________________________ -->
4781<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4782 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4783</div>
4784<div class="doc_text">
4785
4786<h5>Syntax:</h5>
4787<pre>
4788 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4789</pre>
4790
4791<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4792<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4793 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4794
4795<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4796<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4797 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4798 <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]4799
4800<h5>Semantics:</h5>
4801<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4802 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4803 truncating or zero extending that value to the size of the integer type. If
4804 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4805 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4806 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4807 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4808
4809<h5>Example:</h5>
4810<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4811 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4812 %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]4813</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4814
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4815</div>
4816
4817<!-- _______________________________________________________________________ -->
4818<div class="doc_subsubsection">
4819 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4820</div>
4821<div class="doc_text">
4822
4823<h5>Syntax:</h5>
4824<pre>
4825 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4826</pre>
4827
4828<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4829<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4830 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4831
4832<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4833<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4834 value to cast, and a type to cast it to, which must be a
4835 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4836
4837<h5>Semantics:</h5>
4838<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4839 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4840 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4841 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4842 than the size of a pointer then a zero extension is done. If they are the
4843 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4844
4845<h5>Example:</h5>
4846<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4847 %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]4848 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4849 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4850</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4851
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4852</div>
4853
4854<!-- _______________________________________________________________________ -->
4855<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4856 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4857</div>
4858<div class="doc_text">
4859
4860<h5>Syntax:</h5>
4861<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4862 &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]4863</pre>
4864
4865<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4866<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4867 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4868
4869<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4870<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4871 non-aggregate first class value, and a type to cast it to, which must also be
4872 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4873 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4874 identical. If the source type is a pointer, the destination type must also be
4875 a pointer. This instruction supports bitwise conversion of vectors to
4876 integers and to vectors of other types (as long as they have the same
4877 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4878
4879<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4880<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4881 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4882 this conversion. The conversion is done as if the <tt>value</tt> had been
4883 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4884 be converted to other pointer types with this instruction. To convert
4885 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4886 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4887
4888<h5>Example:</h5>
4889<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4890 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4891 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4892 %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]4893</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4894
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4895</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4896
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4897<!-- ======================================================================= -->
4898<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4899
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4900<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4901
4902<p>The instructions in this category are the "miscellaneous" instructions, which
4903 defy better classification.</p>
4904
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4905</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4906
4907<!-- _______________________________________________________________________ -->
4908<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4909</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4910
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4911<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4912
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4913<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4914<pre>
4915 &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]4916</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4917
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4918<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4919<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4920 boolean values based on comparison of its two integer, integer vector, or
4921 pointer operands.</p>
4922
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4923<h5>Arguments:</h5>
4924<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4925 the condition code indicating the kind of comparison to perform. It is not a
4926 value, just a keyword. The possible condition code are:</p>
4927
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4928<ol>
4929 <li><tt>eq</tt>: equal</li>
4930 <li><tt>ne</tt>: not equal </li>
4931 <li><tt>ugt</tt>: unsigned greater than</li>
4932 <li><tt>uge</tt>: unsigned greater or equal</li>
4933 <li><tt>ult</tt>: unsigned less than</li>
4934 <li><tt>ule</tt>: unsigned less or equal</li>
4935 <li><tt>sgt</tt>: signed greater than</li>
4936 <li><tt>sge</tt>: signed greater or equal</li>
4937 <li><tt>slt</tt>: signed less than</li>
4938 <li><tt>sle</tt>: signed less or equal</li>
4939</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4940
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4941<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4942 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4943 typed. They must also be identical types.</p>
4944
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4945<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4946<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4947 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]4948 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]4949 result, as follows:</p>
4950
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4951<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4952 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4953 <tt>false</tt> otherwise. No sign interpretation is necessary or
4954 performed.</li>
4955
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4956 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4957 <tt>false</tt> otherwise. No sign interpretation is necessary or
4958 performed.</li>
4959
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4960 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4961 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4962
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4963 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4964 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4965 to <tt>op2</tt>.</li>
4966
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4967 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4968 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4969
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4970 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4971 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4972
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4973 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4974 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4975
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4976 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4977 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4978 to <tt>op2</tt>.</li>
4979
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4980 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4981 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4982
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4983 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4984 <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]4985</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4986
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4987<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4988 values are compared as if they were integers.</p>
4989
4990<p>If the operands are integer vectors, then they are compared element by
4991 element. The result is an <tt>i1</tt> vector with the same number of elements
4992 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4993
4994<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4995<pre>
4996 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4997 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4998 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4999 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5000 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5001 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5002</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5003
5004<p>Note that the code generator does not yet support vector types with
5005 the <tt>icmp</tt> instruction.</p>
5006
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5007</div>
5008
5009<!-- _______________________________________________________________________ -->
5010<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5011</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5012
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5013<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5014
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5015<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5016<pre>
5017 &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]5018</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5019
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5020<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5021<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5022 values based on comparison of its operands.</p>
5023
5024<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]5025(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5026
5027<p>If the operands are floating point vectors, then the result type is a vector
5028 of boolean with the same number of elements as the operands being
5029 compared.</p>
5030
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5031<h5>Arguments:</h5>
5032<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5033 the condition code indicating the kind of comparison to perform. It is not a
5034 value, just a keyword. The possible condition code are:</p>
5035
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5036<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5037 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5038 <li><tt>oeq</tt>: ordered and equal</li>
5039 <li><tt>ogt</tt>: ordered and greater than </li>
5040 <li><tt>oge</tt>: ordered and greater than or equal</li>
5041 <li><tt>olt</tt>: ordered and less than </li>
5042 <li><tt>ole</tt>: ordered and less than or equal</li>
5043 <li><tt>one</tt>: ordered and not equal</li>
5044 <li><tt>ord</tt>: ordered (no nans)</li>
5045 <li><tt>ueq</tt>: unordered or equal</li>
5046 <li><tt>ugt</tt>: unordered or greater than </li>
5047 <li><tt>uge</tt>: unordered or greater than or equal</li>
5048 <li><tt>ult</tt>: unordered or less than </li>
5049 <li><tt>ule</tt>: unordered or less than or equal</li>
5050 <li><tt>une</tt>: unordered or not equal</li>
5051 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5052 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5053</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5054
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5055<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5056 <i>unordered</i> means that either operand may be a QNAN.</p>
5057
5058<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5059 a <a href="#t_floating">floating point</a> type or
5060 a <a href="#t_vector">vector</a> of floating point type. They must have
5061 identical types.</p>
5062
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5063<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]5064<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5065 according to the condition code given as <tt>cond</tt>. If the operands are
5066 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5067 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5068 follows:</p>
5069
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5070<ol>
5071 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5072
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5073 <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]5074 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5075
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5076 <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]5077 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5078
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5079 <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]5080 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5081
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5082 <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]5083 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5084
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5085 <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]5086 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5087
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5088 <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]5089 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5090
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5091 <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]5092
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5093 <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]5094 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5095
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5096 <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]5097 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5098
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5099 <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]5100 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5101
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5102 <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]5103 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5104
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5105 <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]5106 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5107
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5108 <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]5109 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5110
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5111 <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]5112
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5113 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5114</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5115
5116<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5117<pre>
5118 &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]5119 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5120 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5121 &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]5122</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5123
5124<p>Note that the code generator does not yet support vector types with
5125 the <tt>fcmp</tt> instruction.</p>
5126
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5127</div>
5128
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5129<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]5130<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5131 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
5132</div>
5133
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5134<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5135
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5136<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5137<pre>
5138 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5139</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5140
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5141<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5142<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5143 SSA graph representing the function.</p>
5144
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5145<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5146<p>The type of the incoming values is specified with the first type field. After
5147 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5148 one pair for each predecessor basic block of the current block. Only values
5149 of <a href="#t_firstclass">first class</a> type may be used as the value
5150 arguments to the PHI node. Only labels may be used as the label
5151 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5152
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5153<p>There must be no non-phi instructions between the start of a basic block and
5154 the PHI instructions: i.e. PHI instructions must be first in a basic
5155 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5156
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5157<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5158 occur on the edge from the corresponding predecessor block to the current
5159 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5160 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]5161
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5162<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5163<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5164 specified by the pair corresponding to the predecessor basic block that
5165 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5166
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5167<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5168<pre>
5169Loop: ; Infinite loop that counts from 0 on up...
5170 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5171 %nextindvar = add i32 %indvar, 1
5172 br label %Loop
5173</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5174
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5175</div>
5176
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5177<!-- _______________________________________________________________________ -->
5178<div class="doc_subsubsection">
5179 <a name="i_select">'<tt>select</tt>' Instruction</a>
5180</div>
5181
5182<div class="doc_text">
5183
5184<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5185<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5186 &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>
5187
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5188 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5189</pre>
5190
5191<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5192<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5193 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5194
5195
5196<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5197<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5198 values indicating the condition, and two values of the
5199 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5200 vectors and the condition is a scalar, then entire vectors are selected, not
5201 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5202
5203<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5204<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5205 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5206
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5207<p>If the condition is a vector of i1, then the value arguments must be vectors
5208 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5209
5210<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5211<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5212 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5213</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5214
5215<p>Note that the code generator does not yet support conditions
5216 with vector type.</p>
5217
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5218</div>
5219
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5220<!-- _______________________________________________________________________ -->
5221<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5222 <a name="i_call">'<tt>call</tt>' Instruction</a>
5223</div>
5224
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5225<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5226
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5227<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5228<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]5229 &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]5230</pre>
5231
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5232<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5233<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5234
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5235<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5236<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5237
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5238<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5239 <li>The optional "tail" marker indicates that the callee function does not
5240 access any allocas or varargs in the caller. Note that calls may be
5241 marked "tail" even if they do not occur before
5242 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5243 present, the function call is eligible for tail call optimization,
5244 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Chengdc444e92010-03-08 21:05:02 +0000[diff] [blame]5245 optimized into a jump</a>. The code generator may optimize calls marked
5246 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5247 sibling call optimization</a> when the caller and callee have
5248 matching signatures, or 2) forced tail call optimization when the
5249 following extra requirements are met:
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5250 <ul>
5251 <li>Caller and callee both have the calling
5252 convention <tt>fastcc</tt>.</li>
5253 <li>The call is in tail position (ret immediately follows call and ret
5254 uses value of call or is void).</li>
5255 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohmanfbbee8d2010-03-02 01:08:11 +0000[diff] [blame]5256 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5257 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5258 constraints are met.</a></li>
5259 </ul>
5260 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5261
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5262 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5263 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5264 defaults to using C calling conventions. The calling convention of the
5265 call must match the calling convention of the target function, or else the
5266 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5267
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5268 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5269 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5270 '<tt>inreg</tt>' attributes are valid here.</li>
5271
5272 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5273 type of the return value. Functions that return no value are marked
5274 <tt><a href="#t_void">void</a></tt>.</li>
5275
5276 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5277 being invoked. The argument types must match the types implied by this
5278 signature. This type can be omitted if the function is not varargs and if
5279 the function type does not return a pointer to a function.</li>
5280
5281 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5282 be invoked. In most cases, this is a direct function invocation, but
5283 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5284 to function value.</li>
5285
5286 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]5287 signature argument types and parameter attributes. All arguments must be
5288 of <a href="#t_firstclass">first class</a> type. If the function
5289 signature indicates the function accepts a variable number of arguments,
5290 the extra arguments can be specified.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5291
5292 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5293 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5294 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5295</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5296
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5297<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5298<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5299 a specified function, with its incoming arguments bound to the specified
5300 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5301 function, control flow continues with the instruction after the function
5302 call, and the return value of the function is bound to the result
5303 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5304
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5305<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5306<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]5307 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]5308 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
5309 %X = tail call i32 @foo() <i>; yields i32</i>
5310 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5311 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]5312
5313 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5314 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]5315 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5316 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]5317 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]5318 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5319</pre>
5320
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5321<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]5322standard C99 library as being the C99 library functions, and may perform
5323optimizations or generate code for them under that assumption. This is
5324something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5325freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5326
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5327</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5328
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5329<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5330<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]5331 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5332</div>
5333
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5334<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5335
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5336<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5337<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5338 &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]5339</pre>
5340
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5341<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5342<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5343 the "variable argument" area of a function call. It is used to implement the
5344 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5345
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5346<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5347<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5348 argument. It returns a value of the specified argument type and increments
5349 the <tt>va_list</tt> to point to the next argument. The actual type
5350 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5351
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5352<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5353<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5354 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5355 to the next argument. For more information, see the variable argument
5356 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5357
5358<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]5359 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5360 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5361
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5362<p><tt>va_arg</tt> is an LLVM instruction instead of
5363 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5364 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5365
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5366<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5367<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5368
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5369<p>Note that the code generator does not yet fully support va_arg on many
5370 targets. Also, it does not currently support va_arg with aggregate types on
5371 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]5372
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5373</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5374
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5375<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]5376<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
5377<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5378
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5379<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5380
5381<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5382 well known names and semantics and are required to follow certain
5383 restrictions. Overall, these intrinsics represent an extension mechanism for
5384 the LLVM language that does not require changing all of the transformations
5385 in LLVM when adding to the language (or the bitcode reader/writer, the
5386 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5387
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5388<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5389 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5390 begin with this prefix. Intrinsic functions must always be external
5391 functions: you cannot define the body of intrinsic functions. Intrinsic
5392 functions may only be used in call or invoke instructions: it is illegal to
5393 take the address of an intrinsic function. Additionally, because intrinsic
5394 functions are part of the LLVM language, it is required if any are added that
5395 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5396
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5397<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5398 family of functions that perform the same operation but on different data
5399 types. Because LLVM can represent over 8 million different integer types,
5400 overloading is used commonly to allow an intrinsic function to operate on any
5401 integer type. One or more of the argument types or the result type can be
5402 overloaded to accept any integer type. Argument types may also be defined as
5403 exactly matching a previous argument's type or the result type. This allows
5404 an intrinsic function which accepts multiple arguments, but needs all of them
5405 to be of the same type, to only be overloaded with respect to a single
5406 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5407
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5408<p>Overloaded intrinsics will have the names of its overloaded argument types
5409 encoded into its function name, each preceded by a period. Only those types
5410 which are overloaded result in a name suffix. Arguments whose type is matched
5411 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5412 can take an integer of any width and returns an integer of exactly the same
5413 integer width. This leads to a family of functions such as
5414 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5415 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5416 suffix is required. Because the argument's type is matched against the return
5417 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5418
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5419<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5420 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5421
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5422</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5423
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5424<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5425<div class="doc_subsection">
5426 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
5427</div>
5428
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5429<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5430
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5431<p>Variable argument support is defined in LLVM with
5432 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5433 intrinsic functions. These functions are related to the similarly named
5434 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5435
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5436<p>All of these functions operate on arguments that use a target-specific value
5437 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5438 not define what this type is, so all transformations should be prepared to
5439 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5440
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]5441<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]5442 instruction and the variable argument handling intrinsic functions are
5443 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5444
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5445<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5446<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5447define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5448 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5449 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5450 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5451 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5452
5453 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5454 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5455
5456 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5457 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5458 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5459 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5460 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5461
5462 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5463 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5464 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5465}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5466
5467declare void @llvm.va_start(i8*)
5468declare void @llvm.va_copy(i8*, i8*)
5469declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5470</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5471</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5472
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5473</div>
5474
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5475<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5476<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5477 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5478</div>
5479
5480
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5481<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5482
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5483<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5484<pre>
5485 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5486</pre>
5487
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5488<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5489<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5490 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]5491
5492<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5493<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]5494
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5495<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5496<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]5497 macro available in C. In a target-dependent way, it initializes
5498 the <tt>va_list</tt> element to which the argument points, so that the next
5499 call to <tt>va_arg</tt> will produce the first variable argument passed to
5500 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5501 need to know the last argument of the function as the compiler can figure
5502 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5503
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5504</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5505
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5506<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5507<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5508 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5509</div>
5510
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5511<div class="doc_text">
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5512
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5513<h5>Syntax:</h5>
5514<pre>
5515 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5516</pre>
5517
5518<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5519<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5520 which has been initialized previously
5521 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5522 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5523
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5524<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5525<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]5526
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5527<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5528<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]5529 macro available in C. In a target-dependent way, it destroys
5530 the <tt>va_list</tt> element to which the argument points. Calls
5531 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5532 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5533 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5534
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5535</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5536
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5537<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5538<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5539 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5540</div>
5541
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5542<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5543
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5544<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5545<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5546 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5547</pre>
5548
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5549<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5550<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5551 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5552
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5553<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5554<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]5555 The second argument is a pointer to a <tt>va_list</tt> element to copy
5556 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5557
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5558<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5559<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]5560 macro available in C. In a target-dependent way, it copies the
5561 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5562 element. This intrinsic is necessary because
5563 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5564 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5565
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5566</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5567
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5568<!-- ======================================================================= -->
5569<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5570 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5571</div>
5572
5573<div class="doc_text">
5574
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5575<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5576Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5577intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5578roots on the stack</a>, as well as garbage collector implementations that
5579require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5580barriers. Front-ends for type-safe garbage collected languages should generate
5581these intrinsics to make use of the LLVM garbage collectors. For more details,
5582see <a href="GarbageCollection.html">Accurate Garbage Collection with
5583LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5584
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5585<p>The garbage collection intrinsics only operate on objects in the generic
5586 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5587
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5588</div>
5589
5590<!-- _______________________________________________________________________ -->
5591<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5592 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5593</div>
5594
5595<div class="doc_text">
5596
5597<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5598<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5599 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5600</pre>
5601
5602<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]5603<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]5604 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5605
5606<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5607<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5608 root pointer. The second pointer (which must be either a constant or a
5609 global value address) contains the meta-data to be associated with the
5610 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5611
5612<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]5613<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]5614 location. At compile-time, the code generator generates information to allow
5615 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5616 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5617 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5618
5619</div>
5620
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5621<!-- _______________________________________________________________________ -->
5622<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5623 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5624</div>
5625
5626<div class="doc_text">
5627
5628<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5629<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5630 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5631</pre>
5632
5633<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5634<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5635 locations, allowing garbage collector implementations that require read
5636 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5637
5638<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5639<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]5640 allocated from the garbage collector. The first object is a pointer to the
5641 start of the referenced object, if needed by the language runtime (otherwise
5642 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5643
5644<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5645<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5646 instruction, but may be replaced with substantially more complex code by the
5647 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5648 may only be used in a function which <a href="#gc">specifies a GC
5649 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5650
5651</div>
5652
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5653<!-- _______________________________________________________________________ -->
5654<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5655 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5656</div>
5657
5658<div class="doc_text">
5659
5660<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5661<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5662 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5663</pre>
5664
5665<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5666<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5667 locations, allowing garbage collector implementations that require write
5668 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5669
5670<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5671<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]5672 object to store it to, and the third is the address of the field of Obj to
5673 store to. If the runtime does not require a pointer to the object, Obj may
5674 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5675
5676<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5677<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5678 instruction, but may be replaced with substantially more complex code by the
5679 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5680 may only be used in a function which <a href="#gc">specifies a GC
5681 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5682
5683</div>
5684
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5685<!-- ======================================================================= -->
5686<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5687 <a name="int_codegen">Code Generator Intrinsics</a>
5688</div>
5689
5690<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5691
5692<p>These intrinsics are provided by LLVM to expose special features that may
5693 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5694
5695</div>
5696
5697<!-- _______________________________________________________________________ -->
5698<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5699 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5700</div>
5701
5702<div class="doc_text">
5703
5704<h5>Syntax:</h5>
5705<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5706 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5707</pre>
5708
5709<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5710<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5711 target-specific value indicating the return address of the current function
5712 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5713
5714<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5715<p>The argument to this intrinsic indicates which function to return the address
5716 for. Zero indicates the calling function, one indicates its caller, etc.
5717 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5718
5719<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5720<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5721 indicating the return address of the specified call frame, or zero if it
5722 cannot be identified. The value returned by this intrinsic is likely to be
5723 incorrect or 0 for arguments other than zero, so it should only be used for
5724 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5725
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5726<p>Note that calling this intrinsic does not prevent function inlining or other
5727 aggressive transformations, so the value returned may not be that of the
5728 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5729
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5730</div>
5731
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5732<!-- _______________________________________________________________________ -->
5733<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5734 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5735</div>
5736
5737<div class="doc_text">
5738
5739<h5>Syntax:</h5>
5740<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5741 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5742</pre>
5743
5744<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5745<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5746 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5747
5748<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5749<p>The argument to this intrinsic indicates which function to return the frame
5750 pointer for. Zero indicates the calling function, one indicates its caller,
5751 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5752
5753<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5754<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5755 indicating the frame address of the specified call frame, or zero if it
5756 cannot be identified. The value returned by this intrinsic is likely to be
5757 incorrect or 0 for arguments other than zero, so it should only be used for
5758 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5759
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5760<p>Note that calling this intrinsic does not prevent function inlining or other
5761 aggressive transformations, so the value returned may not be that of the
5762 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5763
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5764</div>
5765
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5766<!-- _______________________________________________________________________ -->
5767<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5768 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5769</div>
5770
5771<div class="doc_text">
5772
5773<h5>Syntax:</h5>
5774<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5775 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +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.stacksave</tt>' intrinsic is used to remember the current state
5780 of the function stack, for use
5781 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5782 useful for implementing language features like scoped automatic variable
5783 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5784
5785<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5786<p>This intrinsic returns a opaque pointer value that can be passed
5787 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5788 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5789 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5790 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5791 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5792 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5793
5794</div>
5795
5796<!-- _______________________________________________________________________ -->
5797<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5798 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5799</div>
5800
5801<div class="doc_text">
5802
5803<h5>Syntax:</h5>
5804<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5805 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5806</pre>
5807
5808<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5809<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5810 the function stack to the state it was in when the
5811 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5812 executed. This is useful for implementing language features like scoped
5813 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5814
5815<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5816<p>See the description
5817 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5818
5819</div>
5820
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5821<!-- _______________________________________________________________________ -->
5822<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5823 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5824</div>
5825
5826<div class="doc_text">
5827
5828<h5>Syntax:</h5>
5829<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5830 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]5831</pre>
5832
5833<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5834<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5835 insert a prefetch instruction if supported; otherwise, it is a noop.
5836 Prefetches have no effect on the behavior of the program but can change its
5837 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5838
5839<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5840<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5841 specifier determining if the fetch should be for a read (0) or write (1),
5842 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5843 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5844 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5845
5846<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5847<p>This intrinsic does not modify the behavior of the program. In particular,
5848 prefetches cannot trap and do not produce a value. On targets that support
5849 this intrinsic, the prefetch can provide hints to the processor cache for
5850 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5851
5852</div>
5853
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5854<!-- _______________________________________________________________________ -->
5855<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5856 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5857</div>
5858
5859<div class="doc_text">
5860
5861<h5>Syntax:</h5>
5862<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5863 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5864</pre>
5865
5866<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5867<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5868 Counter (PC) in a region of code to simulators and other tools. The method
5869 is target specific, but it is expected that the marker will use exported
5870 symbols to transmit the PC of the marker. The marker makes no guarantees
5871 that it will remain with any specific instruction after optimizations. It is
5872 possible that the presence of a marker will inhibit optimizations. The
5873 intended use is to be inserted after optimizations to allow correlations of
5874 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5875
5876<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5877<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5878
5879<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5880<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5881 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5882
5883</div>
5884
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5885<!-- _______________________________________________________________________ -->
5886<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5887 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5888</div>
5889
5890<div class="doc_text">
5891
5892<h5>Syntax:</h5>
5893<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5894 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5895</pre>
5896
5897<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5898<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5899 counter register (or similar low latency, high accuracy clocks) on those
5900 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5901 should map to RPCC. As the backing counters overflow quickly (on the order
5902 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5903
5904<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5905<p>When directly supported, reading the cycle counter should not modify any
5906 memory. Implementations are allowed to either return a application specific
5907 value or a system wide value. On backends without support, this is lowered
5908 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5909
5910</div>
5911
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5912<!-- ======================================================================= -->
5913<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5914 <a name="int_libc">Standard C Library Intrinsics</a>
5915</div>
5916
5917<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5918
5919<p>LLVM provides intrinsics for a few important standard C library functions.
5920 These intrinsics allow source-language front-ends to pass information about
5921 the alignment of the pointer arguments to the code generator, providing
5922 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5923
5924</div>
5925
5926<!-- _______________________________________________________________________ -->
5927<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5928 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5929</div>
5930
5931<div class="doc_text">
5932
5933<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5934<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]5935 integer bit width and for different address spaces. Not all targets support
5936 all bit widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5937
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5938<pre>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]5939 declare void @llvm.memcpy.p0i8.p0i8.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5940 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
5941 declare void @llvm.memcpy.p0i8.p0i8.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5942 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5943</pre>
5944
5945<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5946<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5947 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5948
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5949<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]5950 intrinsics do not return a value, takes extra alignment/isvolatile arguments
5951 and the pointers can be in specified address spaces.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5952
5953<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]5954
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5955<p>The first argument is a pointer to the destination, the second is a pointer
5956 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]5957 number of bytes to copy, the fourth argument is the alignment of the
5958 source and destination locations, and the fifth is a boolean indicating a
5959 volatile access.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5960
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5961<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]5962 then the caller guarantees that both the source and destination pointers are
5963 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5964
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]5965<p>Volatile accesses should not be deleted if dead, but the access behavior is
5966 not very cleanly specified and it is unwise to depend on it.</p>
5967
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5968<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]5969
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5970<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5971 source location to the destination location, which are not allowed to
5972 overlap. It copies "len" bytes of memory over. If the argument is known to
5973 be aligned to some boundary, this can be specified as the fourth argument,
5974 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5975
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5976</div>
5977
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5978<!-- _______________________________________________________________________ -->
5979<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5980 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5981</div>
5982
5983<div class="doc_text">
5984
5985<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5986<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]5987 width and for different address space. Not all targets support all bit
5988 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5989
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5990<pre>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]5991 declare void @llvm.memmove.p0i8.p0i8.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5992 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
5993 declare void @llvm.memmove.p0i8.p0i8.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5994 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5995</pre>
5996
5997<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5998<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5999 source location to the destination location. It is similar to the
6000 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6001 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6002
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6003<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6004 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6005 and the pointers can be in specified address spaces.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6006
6007<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6008
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6009<p>The first argument is a pointer to the destination, the second is a pointer
6010 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6011 number of bytes to copy, the fourth argument is the alignment of the
6012 source and destination locations, and the fifth is a boolean indicating a
6013 volatile access.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6014
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6015<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]6016 then the caller guarantees that the source and destination pointers are
6017 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6018
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6019<p>Volatile accesses should not be deleted if dead, but the access behavior is
6020 not very cleanly specified and it is unwise to depend on it.</p>
6021
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6022<h5>Semantics:</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 '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6025 source location to the destination location, which may overlap. It copies
6026 "len" bytes of memory over. If the argument is known to be aligned to some
6027 boundary, this can be specified as the fourth argument, otherwise it should
6028 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6029
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6030</div>
6031
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6032<!-- _______________________________________________________________________ -->
6033<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6034 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6035</div>
6036
6037<div class="doc_text">
6038
6039<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6040<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]6041 width and for different address spaces. Not all targets support all bit
6042 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6043
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6044<pre>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6045 declare void @llvm.memset.p0i8.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6046 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6047 declare void @llvm.memset.p0i8.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6048 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6049</pre>
6050
6051<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6052<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6053 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6054
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6055<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6056 intrinsic does not return a value, takes extra alignment/volatile arguments,
6057 and the destination can be in an arbitrary address space.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6058
6059<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6060<p>The first argument is a pointer to the destination to fill, the second is the
6061 byte value to fill it with, the third argument is an integer argument
6062 specifying the number of bytes to fill, and the fourth argument is the known
6063 alignment of destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6064
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6065<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]6066 then the caller guarantees that the destination pointer is aligned to that
6067 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6068
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6069<p>Volatile accesses should not be deleted if dead, but the access behavior is
6070 not very cleanly specified and it is unwise to depend on it.</p>
6071
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6072<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6073<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6074 at the destination location. If the argument is known to be aligned to some
6075 boundary, this can be specified as the fourth argument, otherwise it should
6076 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6077
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6078</div>
6079
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6080<!-- _______________________________________________________________________ -->
6081<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6082 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6083</div>
6084
6085<div class="doc_text">
6086
6087<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6088<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6089 floating point or vector of floating point type. Not all targets support all
6090 types however.</p>
6091
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6092<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6093 declare float @llvm.sqrt.f32(float %Val)
6094 declare double @llvm.sqrt.f64(double %Val)
6095 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6096 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6097 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6098</pre>
6099
6100<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6101<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6102 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6103 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6104 behavior for negative numbers other than -0.0 (which allows for better
6105 optimization, because there is no need to worry about errno being
6106 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]6107
6108<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6109<p>The argument and return value are floating point numbers of the same
6110 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6111
6112<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6113<p>This function returns the sqrt of the specified operand if it is a
6114 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6115
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6116</div>
6117
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6118<!-- _______________________________________________________________________ -->
6119<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6120 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6121</div>
6122
6123<div class="doc_text">
6124
6125<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6126<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6127 floating point or vector of floating point type. Not all targets support all
6128 types however.</p>
6129
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6130<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6131 declare float @llvm.powi.f32(float %Val, i32 %power)
6132 declare double @llvm.powi.f64(double %Val, i32 %power)
6133 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6134 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6135 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6136</pre>
6137
6138<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6139<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6140 specified (positive or negative) power. The order of evaluation of
6141 multiplications is not defined. When a vector of floating point type is
6142 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6143
6144<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6145<p>The second argument is an integer power, and the first is a value to raise to
6146 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6147
6148<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6149<p>This function returns the first value raised to the second power with an
6150 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6151
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6152</div>
6153
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6154<!-- _______________________________________________________________________ -->
6155<div class="doc_subsubsection">
6156 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
6157</div>
6158
6159<div class="doc_text">
6160
6161<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6162<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6163 floating point or vector of floating point type. Not all targets support all
6164 types however.</p>
6165
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6166<pre>
6167 declare float @llvm.sin.f32(float %Val)
6168 declare double @llvm.sin.f64(double %Val)
6169 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6170 declare fp128 @llvm.sin.f128(fp128 %Val)
6171 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6172</pre>
6173
6174<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6175<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6176
6177<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6178<p>The argument and return value are floating point numbers of the same
6179 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6180
6181<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6182<p>This function returns the sine of the specified operand, returning the same
6183 values as the libm <tt>sin</tt> functions would, and handles error conditions
6184 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6185
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6186</div>
6187
6188<!-- _______________________________________________________________________ -->
6189<div class="doc_subsubsection">
6190 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
6191</div>
6192
6193<div class="doc_text">
6194
6195<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6196<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6197 floating point or vector of floating point type. Not all targets support all
6198 types however.</p>
6199
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6200<pre>
6201 declare float @llvm.cos.f32(float %Val)
6202 declare double @llvm.cos.f64(double %Val)
6203 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6204 declare fp128 @llvm.cos.f128(fp128 %Val)
6205 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6206</pre>
6207
6208<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6209<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6210
6211<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6212<p>The argument and return value are floating point numbers of the same
6213 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6214
6215<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6216<p>This function returns the cosine of the specified operand, returning the same
6217 values as the libm <tt>cos</tt> functions would, and handles error conditions
6218 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6219
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6220</div>
6221
6222<!-- _______________________________________________________________________ -->
6223<div class="doc_subsubsection">
6224 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
6225</div>
6226
6227<div class="doc_text">
6228
6229<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6230<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6231 floating point or vector of floating point type. Not all targets support all
6232 types however.</p>
6233
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6234<pre>
6235 declare float @llvm.pow.f32(float %Val, float %Power)
6236 declare double @llvm.pow.f64(double %Val, double %Power)
6237 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6238 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6239 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6240</pre>
6241
6242<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6243<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6244 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6245
6246<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6247<p>The second argument is a floating point power, and the first is a value to
6248 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6249
6250<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6251<p>This function returns the first value raised to the second power, returning
6252 the same values as the libm <tt>pow</tt> functions would, and handles error
6253 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6254
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6255</div>
6256
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6257<!-- ======================================================================= -->
6258<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6259 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6260</div>
6261
6262<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6263
6264<p>LLVM provides intrinsics for a few important bit manipulation operations.
6265 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6266
6267</div>
6268
6269<!-- _______________________________________________________________________ -->
6270<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6271 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6272</div>
6273
6274<div class="doc_text">
6275
6276<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6277<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6278 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6279
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6280<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6281 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6282 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6283 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6284</pre>
6285
6286<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6287<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6288 values with an even number of bytes (positive multiple of 16 bits). These
6289 are useful for performing operations on data that is not in the target's
6290 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6291
6292<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6293<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6294 and low byte of the input i16 swapped. Similarly,
6295 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6296 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6297 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6298 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6299 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6300 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6301
6302</div>
6303
6304<!-- _______________________________________________________________________ -->
6305<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]6306 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6307</div>
6308
6309<div class="doc_text">
6310
6311<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6312<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]6313 width. Not all targets support all bit widths however.</p>
6314
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6315<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6316 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6317 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6318 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6319 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6320 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6321</pre>
6322
6323<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6324<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6325 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6326
6327<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6328<p>The only argument is the value to be counted. The argument may be of any
6329 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6330
6331<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6332<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]6333
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6334</div>
6335
6336<!-- _______________________________________________________________________ -->
6337<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6338 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6339</div>
6340
6341<div class="doc_text">
6342
6343<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6344<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
6345 integer bit width. Not all targets support all bit widths however.</p>
6346
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6347<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6348 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6349 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6350 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6351 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6352 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6353</pre>
6354
6355<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6356<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6357 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6358
6359<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6360<p>The only argument is the value to be counted. The argument may be of any
6361 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6362
6363<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6364<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
6365 zeros in a variable. If the src == 0 then the result is the size in bits of
6366 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6367
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6368</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6369
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6370<!-- _______________________________________________________________________ -->
6371<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6372 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6373</div>
6374
6375<div class="doc_text">
6376
6377<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6378<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
6379 integer bit width. Not all targets support all bit widths however.</p>
6380
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6381<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6382 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6383 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6384 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6385 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6386 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6387</pre>
6388
6389<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6390<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6391 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6392
6393<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6394<p>The only argument is the value to be counted. The argument may be of any
6395 integer type. The return type must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6396
6397<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6398<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
6399 zeros in a variable. If the src == 0 then the result is the size in bits of
6400 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6401
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6402</div>
6403
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6404<!-- ======================================================================= -->
6405<div class="doc_subsection">
6406 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
6407</div>
6408
6409<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6410
6411<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6412
6413</div>
6414
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6415<!-- _______________________________________________________________________ -->
6416<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6417 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6418</div>
6419
6420<div class="doc_text">
6421
6422<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6423<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]6424 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6425
6426<pre>
6427 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6428 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6429 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6430</pre>
6431
6432<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6433<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6434 a signed addition of the two arguments, and indicate whether an overflow
6435 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6436
6437<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6438<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]6439 be of integer types of any bit width, but they must have the same bit
6440 width. The second element of the result structure must be of
6441 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6442 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6443
6444<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6445<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6446 a signed addition of the two variables. They return a structure &mdash; the
6447 first element of which is the signed summation, and the second element of
6448 which is a bit specifying if the signed summation resulted in an
6449 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6450
6451<h5>Examples:</h5>
6452<pre>
6453 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6454 %sum = extractvalue {i32, i1} %res, 0
6455 %obit = extractvalue {i32, i1} %res, 1
6456 br i1 %obit, label %overflow, label %normal
6457</pre>
6458
6459</div>
6460
6461<!-- _______________________________________________________________________ -->
6462<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6463 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6464</div>
6465
6466<div class="doc_text">
6467
6468<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6469<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]6470 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6471
6472<pre>
6473 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6474 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6475 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6476</pre>
6477
6478<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6479<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6480 an unsigned addition of the two arguments, and indicate whether a carry
6481 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6482
6483<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6484<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]6485 be of integer types of any bit width, but they must have the same bit
6486 width. The second element of the result structure must be of
6487 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6488 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6489
6490<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6491<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6492 an unsigned addition of the two arguments. They return a structure &mdash;
6493 the first element of which is the sum, and the second element of which is a
6494 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6495
6496<h5>Examples:</h5>
6497<pre>
6498 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6499 %sum = extractvalue {i32, i1} %res, 0
6500 %obit = extractvalue {i32, i1} %res, 1
6501 br i1 %obit, label %carry, label %normal
6502</pre>
6503
6504</div>
6505
6506<!-- _______________________________________________________________________ -->
6507<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6508 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6509</div>
6510
6511<div class="doc_text">
6512
6513<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6514<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]6515 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6516
6517<pre>
6518 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6519 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6520 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6521</pre>
6522
6523<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6524<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6525 a signed subtraction of the two arguments, and indicate whether an overflow
6526 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6527
6528<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6529<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]6530 be of integer types of any bit width, but they must have the same bit
6531 width. The second element of the result structure must be of
6532 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6533 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6534
6535<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6536<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6537 a signed subtraction of the two arguments. They return a structure &mdash;
6538 the first element of which is the subtraction, and the second element of
6539 which is a bit specifying if the signed subtraction resulted in an
6540 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6541
6542<h5>Examples:</h5>
6543<pre>
6544 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6545 %sum = extractvalue {i32, i1} %res, 0
6546 %obit = extractvalue {i32, i1} %res, 1
6547 br i1 %obit, label %overflow, label %normal
6548</pre>
6549
6550</div>
6551
6552<!-- _______________________________________________________________________ -->
6553<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6554 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6555</div>
6556
6557<div class="doc_text">
6558
6559<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6560<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]6561 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6562
6563<pre>
6564 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6565 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6566 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6567</pre>
6568
6569<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6570<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6571 an unsigned subtraction of the two arguments, and indicate whether an
6572 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6573
6574<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6575<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]6576 be of integer types of any bit width, but they must have the same bit
6577 width. The second element of the result structure must be of
6578 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6579 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6580
6581<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6582<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6583 an unsigned subtraction of the two arguments. They return a structure &mdash;
6584 the first element of which is the subtraction, and the second element of
6585 which is a bit specifying if the unsigned subtraction resulted in an
6586 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6587
6588<h5>Examples:</h5>
6589<pre>
6590 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6591 %sum = extractvalue {i32, i1} %res, 0
6592 %obit = extractvalue {i32, i1} %res, 1
6593 br i1 %obit, label %overflow, label %normal
6594</pre>
6595
6596</div>
6597
6598<!-- _______________________________________________________________________ -->
6599<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6600 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6601</div>
6602
6603<div class="doc_text">
6604
6605<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6606<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]6607 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6608
6609<pre>
6610 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6611 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6612 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6613</pre>
6614
6615<h5>Overview:</h5>
6616
6617<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6618 a signed multiplication of the two arguments, and indicate whether an
6619 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6620
6621<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6622<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]6623 be of integer types of any bit width, but they must have the same bit
6624 width. The second element of the result structure must be of
6625 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6626 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6627
6628<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6629<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6630 a signed multiplication of the two arguments. They return a structure &mdash;
6631 the first element of which is the multiplication, and the second element of
6632 which is a bit specifying if the signed multiplication resulted in an
6633 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6634
6635<h5>Examples:</h5>
6636<pre>
6637 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6638 %sum = extractvalue {i32, i1} %res, 0
6639 %obit = extractvalue {i32, i1} %res, 1
6640 br i1 %obit, label %overflow, label %normal
6641</pre>
6642
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6643</div>
6644
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6645<!-- _______________________________________________________________________ -->
6646<div class="doc_subsubsection">
6647 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6648</div>
6649
6650<div class="doc_text">
6651
6652<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6653<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]6654 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6655
6656<pre>
6657 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6658 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6659 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6660</pre>
6661
6662<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6663<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6664 a unsigned multiplication of the two arguments, and indicate whether an
6665 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6666
6667<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6668<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]6669 be of integer types of any bit width, but they must have the same bit
6670 width. The second element of the result structure must be of
6671 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6672 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6673
6674<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6675<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6676 an unsigned multiplication of the two arguments. They return a structure
6677 &mdash; the first element of which is the multiplication, and the second
6678 element of which is a bit specifying if the unsigned multiplication resulted
6679 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6680
6681<h5>Examples:</h5>
6682<pre>
6683 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6684 %sum = extractvalue {i32, i1} %res, 0
6685 %obit = extractvalue {i32, i1} %res, 1
6686 br i1 %obit, label %overflow, label %normal
6687</pre>
6688
6689</div>
6690
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6691<!-- ======================================================================= -->
6692<div class="doc_subsection">
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6693 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
6694</div>
6695
6696<div class="doc_text">
6697
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6698<p>Half precision floating point is a storage-only format. This means that it is
6699 a dense encoding (in memory) but does not support computation in the
6700 format.</p>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6701
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6702<p>This means that code must first load the half-precision floating point
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6703 value as an i16, then convert it to float with <a
6704 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
6705 Computation can then be performed on the float value (including extending to
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6706 double etc). To store the value back to memory, it is first converted to
6707 float if needed, then converted to i16 with
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6708 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
6709 storing as an i16 value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6710</div>
6711
6712<!-- _______________________________________________________________________ -->
6713<div class="doc_subsubsection">
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6714 <a name="int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6715</div>
6716
6717<div class="doc_text">
6718
6719<h5>Syntax:</h5>
6720<pre>
6721 declare i16 @llvm.convert.to.fp16(f32 %a)
6722</pre>
6723
6724<h5>Overview:</h5>
6725<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
6726 a conversion from single precision floating point format to half precision
6727 floating point format.</p>
6728
6729<h5>Arguments:</h5>
6730<p>The intrinsic function contains single argument - the value to be
6731 converted.</p>
6732
6733<h5>Semantics:</h5>
6734<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
6735 a conversion from single precision floating point format to half precision
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6736 floating point format. The return value is an <tt>i16</tt> which
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6737 contains the converted number.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6738
6739<h5>Examples:</h5>
6740<pre>
6741 %res = call i16 @llvm.convert.to.fp16(f32 %a)
6742 store i16 %res, i16* @x, align 2
6743</pre>
6744
6745</div>
6746
6747<!-- _______________________________________________________________________ -->
6748<div class="doc_subsubsection">
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6749 <a name="int_convert_from_fp16">'<tt>llvm.convert.from.fp16</tt>' Intrinsic</a>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6750</div>
6751
6752<div class="doc_text">
6753
6754<h5>Syntax:</h5>
6755<pre>
6756 declare f32 @llvm.convert.from.fp16(i16 %a)
6757</pre>
6758
6759<h5>Overview:</h5>
6760<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
6761 a conversion from half precision floating point format to single precision
6762 floating point format.</p>
6763
6764<h5>Arguments:</h5>
6765<p>The intrinsic function contains single argument - the value to be
6766 converted.</p>
6767
6768<h5>Semantics:</h5>
6769<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6770 conversion from half single precision floating point format to single
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6771 precision floating point format. The input half-float value is represented by
6772 an <tt>i16</tt> value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6773
6774<h5>Examples:</h5>
6775<pre>
6776 %a = load i16* @x, align 2
6777 %res = call f32 @llvm.convert.from.fp16(i16 %a)
6778</pre>
6779
6780</div>
6781
6782<!-- ======================================================================= -->
6783<div class="doc_subsection">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6784 <a name="int_debugger">Debugger Intrinsics</a>
6785</div>
6786
6787<div class="doc_text">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6788
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6789<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6790 prefix), are described in
6791 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6792 Level Debugging</a> document.</p>
6793
6794</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6795
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6796<!-- ======================================================================= -->
6797<div class="doc_subsection">
6798 <a name="int_eh">Exception Handling Intrinsics</a>
6799</div>
6800
6801<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6802
6803<p>The LLVM exception handling intrinsics (which all start with
6804 <tt>llvm.eh.</tt> prefix), are described in
6805 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6806 Handling</a> document.</p>
6807
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6808</div>
6809
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6810<!-- ======================================================================= -->
6811<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6812 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6813</div>
6814
6815<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6816
6817<p>This intrinsic makes it possible to excise one parameter, marked with
6818 the <tt>nest</tt> attribute, from a function. The result is a callable
6819 function pointer lacking the nest parameter - the caller does not need to
6820 provide a value for it. Instead, the value to use is stored in advance in a
6821 "trampoline", a block of memory usually allocated on the stack, which also
6822 contains code to splice the nest value into the argument list. This is used
6823 to implement the GCC nested function address extension.</p>
6824
6825<p>For example, if the function is
6826 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6827 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6828 follows:</p>
6829
6830<div class="doc_code">
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6831<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6832 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6833 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6834 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6835 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6836</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6837</div>
6838
6839<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6840 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6841
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6842</div>
6843
6844<!-- _______________________________________________________________________ -->
6845<div class="doc_subsubsection">
6846 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6847</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6848
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6849<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6850
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6851<h5>Syntax:</h5>
6852<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6853 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]6854</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6855
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6856<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6857<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6858 function pointer suitable for executing it.</p>
6859
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6860<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6861<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6862 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6863 sufficiently aligned block of memory; this memory is written to by the
6864 intrinsic. Note that the size and the alignment are target-specific - LLVM
6865 currently provides no portable way of determining them, so a front-end that
6866 generates this intrinsic needs to have some target-specific knowledge.
6867 The <tt>func</tt> argument must hold a function bitcast to
6868 an <tt>i8*</tt>.</p>
6869
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6870<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6871<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6872 dependent code, turning it into a function. A pointer to this function is
6873 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6874 function pointer type</a> before being called. The new function's signature
6875 is the same as that of <tt>func</tt> with any arguments marked with
6876 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6877 is allowed, and it must be of pointer type. Calling the new function is
6878 equivalent to calling <tt>func</tt> with the same argument list, but
6879 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6880 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6881 by <tt>tramp</tt> is modified, then the effect of any later call to the
6882 returned function pointer is undefined.</p>
6883
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6884</div>
6885
6886<!-- ======================================================================= -->
6887<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6888 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6889</div>
6890
6891<div class="doc_text">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6892
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6893<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6894 hardware constructs for atomic operations and memory synchronization. This
6895 provides an interface to the hardware, not an interface to the programmer. It
6896 is aimed at a low enough level to allow any programming models or APIs
6897 (Application Programming Interfaces) which need atomic behaviors to map
6898 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6899 hardware provides a "universal IR" for source languages, it also provides a
6900 starting point for developing a "universal" atomic operation and
6901 synchronization IR.</p>
6902
6903<p>These do <em>not</em> form an API such as high-level threading libraries,
6904 software transaction memory systems, atomic primitives, and intrinsic
6905 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6906 application libraries. The hardware interface provided by LLVM should allow
6907 a clean implementation of all of these APIs and parallel programming models.
6908 No one model or paradigm should be selected above others unless the hardware
6909 itself ubiquitously does so.</p>
6910
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6911</div>
6912
6913<!-- _______________________________________________________________________ -->
6914<div class="doc_subsubsection">
6915 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6916</div>
6917<div class="doc_text">
6918<h5>Syntax:</h5>
6919<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6920 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]6921</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6922
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6923<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6924<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6925 specific pairs of memory access types.</p>
6926
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6927<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6928<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6929 The first four arguments enables a specific barrier as listed below. The
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6930 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6931 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6932
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6933<ul>
6934 <li><tt>ll</tt>: load-load barrier</li>
6935 <li><tt>ls</tt>: load-store barrier</li>
6936 <li><tt>sl</tt>: store-load barrier</li>
6937 <li><tt>ss</tt>: store-store barrier</li>
6938 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6939</ul>
6940
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6941<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6942<p>This intrinsic causes the system to enforce some ordering constraints upon
6943 the loads and stores of the program. This barrier does not
6944 indicate <em>when</em> any events will occur, it only enforces
6945 an <em>order</em> in which they occur. For any of the specified pairs of load
6946 and store operations (f.ex. load-load, or store-load), all of the first
6947 operations preceding the barrier will complete before any of the second
6948 operations succeeding the barrier begin. Specifically the semantics for each
6949 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6950
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6951<ul>
6952 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6953 after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6954 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6955 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6956 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6957 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6958 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6959 load after the barrier begins.</li>
6960</ul>
6961
6962<p>These semantics are applied with a logical "and" behavior when more than one
6963 is enabled in a single memory barrier intrinsic.</p>
6964
6965<p>Backends may implement stronger barriers than those requested when they do
6966 not support as fine grained a barrier as requested. Some architectures do
6967 not need all types of barriers and on such architectures, these become
6968 noops.</p>
6969
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6970<h5>Example:</h5>
6971<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]6972%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6973%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6974 store i32 4, %ptr
6975
6976%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6977 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6978 <i>; guarantee the above finishes</i>
6979 store i32 8, %ptr <i>; before this begins</i>
6980</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6981
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6982</div>
6983
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6984<!-- _______________________________________________________________________ -->
6985<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6986 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6987</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6988
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6989<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6990
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6991<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6992<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6993 any integer bit width and for different address spaces. Not all targets
6994 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6995
6996<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6997 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6998 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6999 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
7000 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]7001</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7002
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7003<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7004<p>This loads a value in memory and compares it to a given value. If they are
7005 equal, it stores a new value into the memory.</p>
7006
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7007<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7008<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7009 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7010 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7011 this integer type. While any bit width integer may be used, targets may only
7012 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7013
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7014<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7015<p>This entire intrinsic must be executed atomically. It first loads the value
7016 in memory pointed to by <tt>ptr</tt> and compares it with the
7017 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7018 memory. The loaded value is yielded in all cases. This provides the
7019 equivalent of an atomic compare-and-swap operation within the SSA
7020 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7021
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7022<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7023<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7024%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7025%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7026 store i32 4, %ptr
7027
7028%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7029%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7030 <i>; yields {i32}:result1 = 4</i>
7031%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7032%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7033
7034%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7035%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7036 <i>; yields {i32}:result2 = 8</i>
7037%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7038
7039%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7040</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7041
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7042</div>
7043
7044<!-- _______________________________________________________________________ -->
7045<div class="doc_subsubsection">
7046 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
7047</div>
7048<div class="doc_text">
7049<h5>Syntax:</h5>
7050
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7051<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7052 integer bit width. Not all targets support all bit widths however.</p>
7053
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7054<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7055 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
7056 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
7057 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
7058 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]7059</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7060
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7061<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7062<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7063 the value from memory. It then stores the value in <tt>val</tt> in the memory
7064 at <tt>ptr</tt>.</p>
7065
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7066<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7067<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7068 the <tt>val</tt> argument and the result must be integers of the same bit
7069 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7070 integer type. The targets may only lower integer representations they
7071 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7072
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7073<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7074<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7075 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7076 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7077
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7078<h5>Examples:</h5>
7079<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7080%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7081%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7082 store i32 4, %ptr
7083
7084%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7085%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7086 <i>; yields {i32}:result1 = 4</i>
7087%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7088%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7089
7090%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7091%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7092 <i>; yields {i32}:result2 = 8</i>
7093
7094%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7095%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7096</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7097
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7098</div>
7099
7100<!-- _______________________________________________________________________ -->
7101<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7102 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7103
7104</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7105
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7106<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7107
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7108<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7109<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7110 any integer bit width. Not all targets support all bit widths however.</p>
7111
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7112<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7113 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7114 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7115 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7116 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]7117</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7118
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7119<h5>Overview:</h5>
7120<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7121 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7122
7123<h5>Arguments:</h5>
7124<p>The intrinsic takes two arguments, the first a pointer to an integer value
7125 and the second an integer value. The result is also an integer value. These
7126 integer types can have any bit width, but they must all have the same bit
7127 width. The targets may only lower integer representations they support.</p>
7128
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7129<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7130<p>This intrinsic does a series of operations atomically. It first loads the
7131 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7132 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]7133
7134<h5>Examples:</h5>
7135<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7136%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7137%ptr = bitcast i8* %mallocP to i32*
7138 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7139%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7140 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7141%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7142 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7143%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7144 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7145%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7146</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7147
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7148</div>
7149
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7150<!-- _______________________________________________________________________ -->
7151<div class="doc_subsubsection">
7152 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
7153
7154</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7155
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7156<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7157
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7158<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7159<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7160 any integer bit width and for different address spaces. Not all targets
7161 support all bit widths however.</p>
7162
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7163<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7164 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7165 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7166 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7167 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]7168</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7169
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7170<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7171<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7172 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7173
7174<h5>Arguments:</h5>
7175<p>The intrinsic takes two arguments, the first a pointer to an integer value
7176 and the second an integer value. The result is also an integer value. These
7177 integer types can have any bit width, but they must all have the same bit
7178 width. The targets may only lower integer representations they support.</p>
7179
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7180<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7181<p>This intrinsic does a series of operations atomically. It first loads the
7182 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7183 result to <tt>ptr</tt>. It yields the original value stored
7184 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7185
7186<h5>Examples:</h5>
7187<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7188%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7189%ptr = bitcast i8* %mallocP to i32*
7190 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7191%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7192 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7193%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7194 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7195%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7196 <i>; yields {i32}:result3 = 2</i>
7197%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7198</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7199
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7200</div>
7201
7202<!-- _______________________________________________________________________ -->
7203<div class="doc_subsubsection">
7204 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
7205 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
7206 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
7207 <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]7208</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7209
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7210<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7211
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7212<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7213<p>These are overloaded intrinsics. You can
7214 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7215 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7216 bit width and for different address spaces. Not all targets support all bit
7217 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7218
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7219<pre>
7220 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7221 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7222 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7223 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]7224</pre>
7225
7226<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7227 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7228 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7229 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7230 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]7231</pre>
7232
7233<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7234 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7235 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7236 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7237 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]7238</pre>
7239
7240<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7241 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7242 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7243 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7244 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]7245</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7246
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7247<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7248<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7249 the value stored in memory at <tt>ptr</tt>. It yields the original value
7250 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7251
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7252<h5>Arguments:</h5>
7253<p>These intrinsics take two arguments, the first a pointer to an integer value
7254 and the second an integer value. The result is also an integer value. These
7255 integer types can have any bit width, but they must all have the same bit
7256 width. The targets may only lower integer representations they support.</p>
7257
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7258<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7259<p>These intrinsics does a series of operations atomically. They first load the
7260 value stored at <tt>ptr</tt>. They then do the bitwise
7261 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7262 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7263
7264<h5>Examples:</h5>
7265<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7266%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7267%ptr = bitcast i8* %mallocP to i32*
7268 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7269%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7270 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7271%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7272 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7273%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7274 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7275%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7276 <i>; yields {i32}:result3 = FF</i>
7277%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7278</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7279
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7280</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7281
7282<!-- _______________________________________________________________________ -->
7283<div class="doc_subsubsection">
7284 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
7285 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
7286 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
7287 <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]7288</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7289
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7290<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7291
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7292<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7293<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7294 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7295 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7296 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7297
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7298<pre>
7299 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7300 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7301 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7302 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]7303</pre>
7304
7305<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7306 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7307 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7308 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7309 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]7310</pre>
7311
7312<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7313 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7314 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7315 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7316 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]7317</pre>
7318
7319<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7320 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7321 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7322 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7323 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]7324</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7325
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7326<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7327<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7328 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7329 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7330
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7331<h5>Arguments:</h5>
7332<p>These intrinsics take two arguments, the first a pointer to an integer value
7333 and the second an integer value. The result is also an integer value. These
7334 integer types can have any bit width, but they must all have the same bit
7335 width. The targets may only lower integer representations they support.</p>
7336
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7337<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7338<p>These intrinsics does a series of operations atomically. They first load the
7339 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7340 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7341 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7342
7343<h5>Examples:</h5>
7344<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7345%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7346%ptr = bitcast i8* %mallocP to i32*
7347 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7348%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7349 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7350%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7351 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7352%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7353 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7354%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7355 <i>; yields {i32}:result3 = 8</i>
7356%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7357</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7358
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7359</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7360
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7361
7362<!-- ======================================================================= -->
7363<div class="doc_subsection">
7364 <a name="int_memorymarkers">Memory Use Markers</a>
7365</div>
7366
7367<div class="doc_text">
7368
7369<p>This class of intrinsics exists to information about the lifetime of memory
7370 objects and ranges where variables are immutable.</p>
7371
7372</div>
7373
7374<!-- _______________________________________________________________________ -->
7375<div class="doc_subsubsection">
7376 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
7377</div>
7378
7379<div class="doc_text">
7380
7381<h5>Syntax:</h5>
7382<pre>
7383 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7384</pre>
7385
7386<h5>Overview:</h5>
7387<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7388 object's lifetime.</p>
7389
7390<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7391<p>The first argument is a constant integer representing the size of the
7392 object, or -1 if it is variable sized. The second argument is a pointer to
7393 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7394
7395<h5>Semantics:</h5>
7396<p>This intrinsic indicates that before this point in the code, the value of the
7397 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]7398 never be used and has an undefined value. A load from the pointer that
7399 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7400 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7401
7402</div>
7403
7404<!-- _______________________________________________________________________ -->
7405<div class="doc_subsubsection">
7406 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
7407</div>
7408
7409<div class="doc_text">
7410
7411<h5>Syntax:</h5>
7412<pre>
7413 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7414</pre>
7415
7416<h5>Overview:</h5>
7417<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7418 object's lifetime.</p>
7419
7420<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7421<p>The first argument is a constant integer representing the size of the
7422 object, or -1 if it is variable sized. The second argument is a pointer to
7423 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7424
7425<h5>Semantics:</h5>
7426<p>This intrinsic indicates that after this point in the code, the value of the
7427 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7428 never be used and has an undefined value. Any stores into the memory object
7429 following this intrinsic may be removed as dead.
7430
7431</div>
7432
7433<!-- _______________________________________________________________________ -->
7434<div class="doc_subsubsection">
7435 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
7436</div>
7437
7438<div class="doc_text">
7439
7440<h5>Syntax:</h5>
7441<pre>
7442 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;) readonly
7443</pre>
7444
7445<h5>Overview:</h5>
7446<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7447 a memory object will not change.</p>
7448
7449<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7450<p>The first argument is a constant integer representing the size of the
7451 object, or -1 if it is variable sized. The second argument is a pointer to
7452 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7453
7454<h5>Semantics:</h5>
7455<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7456 the return value, the referenced memory location is constant and
7457 unchanging.</p>
7458
7459</div>
7460
7461<!-- _______________________________________________________________________ -->
7462<div class="doc_subsubsection">
7463 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
7464</div>
7465
7466<div class="doc_text">
7467
7468<h5>Syntax:</h5>
7469<pre>
7470 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7471</pre>
7472
7473<h5>Overview:</h5>
7474<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7475 a memory object are mutable.</p>
7476
7477<h5>Arguments:</h5>
7478<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7479 The second argument is a constant integer representing the size of the
7480 object, or -1 if it is variable sized and the third argument is a pointer
7481 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7482
7483<h5>Semantics:</h5>
7484<p>This intrinsic indicates that the memory is mutable again.</p>
7485
7486</div>
7487
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7488<!-- ======================================================================= -->
7489<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7490 <a name="int_general">General Intrinsics</a>
7491</div>
7492
7493<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7494
7495<p>This class of intrinsics is designed to be generic and has no specific
7496 purpose.</p>
7497
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7498</div>
7499
7500<!-- _______________________________________________________________________ -->
7501<div class="doc_subsubsection">
7502 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
7503</div>
7504
7505<div class="doc_text">
7506
7507<h5>Syntax:</h5>
7508<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]7509 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]7510</pre>
7511
7512<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7513<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7514
7515<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7516<p>The first argument is a pointer to a value, the second is a pointer to a
7517 global string, the third is a pointer to a global string which is the source
7518 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7519
7520<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7521<p>This intrinsic allows annotation of local variables with arbitrary strings.
7522 This can be useful for special purpose optimizations that want to look for
7523 these annotations. These have no other defined use, they are ignored by code
7524 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7525
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7526</div>
7527
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7528<!-- _______________________________________________________________________ -->
7529<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]7530 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7531</div>
7532
7533<div class="doc_text">
7534
7535<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7536<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7537 any integer bit width.</p>
7538
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7539<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]7540 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7541 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7542 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7543 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7544 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]7545</pre>
7546
7547<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7548<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7549
7550<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7551<p>The first argument is an integer value (result of some expression), the
7552 second is a pointer to a global string, the third is a pointer to a global
7553 string which is the source file name, and the last argument is the line
7554 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7555
7556<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7557<p>This intrinsic allows annotations to be put on arbitrary expressions with
7558 arbitrary strings. This can be useful for special purpose optimizations that
7559 want to look for these annotations. These have no other defined use, they
7560 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7561
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7562</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7563
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7564<!-- _______________________________________________________________________ -->
7565<div class="doc_subsubsection">
7566 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
7567</div>
7568
7569<div class="doc_text">
7570
7571<h5>Syntax:</h5>
7572<pre>
7573 declare void @llvm.trap()
7574</pre>
7575
7576<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7577<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7578
7579<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7580<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7581
7582<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7583<p>This intrinsics is lowered to the target dependent trap instruction. If the
7584 target does not have a trap instruction, this intrinsic will be lowered to
7585 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7586
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7587</div>
7588
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7589<!-- _______________________________________________________________________ -->
7590<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]7591 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7592</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7593
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7594<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7595
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7596<h5>Syntax:</h5>
7597<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7598 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7599</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7600
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7601<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7602<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7603 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7604 ensure that it is placed on the stack before local variables.</p>
7605
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7606<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7607<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7608 arguments. The first argument is the value loaded from the stack
7609 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7610 that has enough space to hold the value of the guard.</p>
7611
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7612<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7613<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7614 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7615 stack. This is to ensure that if a local variable on the stack is
7616 overwritten, it will destroy the value of the guard. When the function exits,
7617 the guard on the stack is checked against the original guard. If they're
7618 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7619 function.</p>
7620
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7621</div>
7622
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7623<!-- _______________________________________________________________________ -->
7624<div class="doc_subsubsection">
7625 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
7626</div>
7627
7628<div class="doc_text">
7629
7630<h5>Syntax:</h5>
7631<pre>
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7632 declare i32 @llvm.objectsize.i32( i8* &lt;object&gt;, i1 &lt;type&gt; )
7633 declare i64 @llvm.objectsize.i64( i8* &lt;object&gt;, i1 &lt;type&gt; )
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7634</pre>
7635
7636<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7637<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information
Eric Christopherd003c5b2010-01-08 21:42:39 +0000[diff] [blame]7638 to the optimizers to discover at compile time either a) when an
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7639 operation like memcpy will either overflow a buffer that corresponds to
7640 an object, or b) to determine that a runtime check for overflow isn't
7641 necessary. An object in this context means an allocation of a
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7642 specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7643
7644<h5>Arguments:</h5>
7645<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7646 argument is a pointer to or into the <tt>object</tt>. The second argument
7647 is a boolean 0 or 1. This argument determines whether you want the
7648 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
7649 1, variables are not allowed.</p>
7650
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7651<h5>Semantics:</h5>
7652<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7653 representing the size of the object concerned or <tt>i32/i64 -1 or 0</tt>
7654 (depending on the <tt>type</tt> argument if the size cannot be determined
7655 at compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7656
7657</div>
7658
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7659<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7660<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7661<address>
7662 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]7663 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7664 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]7665 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]7666
7667 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]7668 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7669 Last modified: $Date$
7670</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]7671
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]7672</body>
7673</html>