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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / b3e1bf54b29354c6d332cfaffcc86cd776fd4ca8 / . / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
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7 <meta name="author" content="Chris Lattner">
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]8 <meta name="description"
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]14
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 Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]69 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]70 <li><a href="#t_function">Function Type</a></li>
71 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]72 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]73 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]74 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]75 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]76 </ol>
77 </li>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]78 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]79 </ol>
80 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]81 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]82 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]83 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]84 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]85 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
86 <li><a href="#undefvalues">Undefined Values</a></li>
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]87 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]88 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]89 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]90 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]91 <li><a href="#othervalues">Other Values</a>
92 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]93 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]94 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]95 </ol>
96 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]97 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
98 <ol>
99 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]100 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
101 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]102 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
103 Global Variable</a></li>
104 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
105 Global Variable</a></li>
106 </ol>
107 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]108 <li><a href="#instref">Instruction Reference</a>
109 <ol>
110 <li><a href="#terminators">Terminator Instructions</a>
111 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]112 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
113 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]114 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]115 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]116 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]117 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]118 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]119 </ol>
120 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]121 <li><a href="#binaryops">Binary Operations</a>
122 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]123 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]124 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]125 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]126 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]127 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]128 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]129 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
130 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
131 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]132 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
133 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
134 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]135 </ol>
136 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]137 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
138 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]139 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
140 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
141 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]142 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]143 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]144 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]145 </ol>
146 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]147 <li><a href="#vectorops">Vector Operations</a>
148 <ol>
149 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
150 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
151 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]152 </ol>
153 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]154 <li><a href="#aggregateops">Aggregate Operations</a>
155 <ol>
156 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
157 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
158 </ol>
159 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]160 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]161 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]162 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]163 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
164 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
165 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]166 </ol>
167 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]168 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]169 <ol>
170 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
171 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
172 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
173 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
174 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]175 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
176 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
177 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
178 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]179 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
180 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]181 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]182 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]183 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]184 <li><a href="#otherops">Other Operations</a>
185 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]186 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
187 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]188 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]189 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]190 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]191 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]192 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]193 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]194 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]195 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]196 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]197 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]198 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
199 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]200 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
201 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
202 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]203 </ol>
204 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]205 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
206 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]207 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
208 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
209 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]210 </ol>
211 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]212 <li><a href="#int_codegen">Code Generator Intrinsics</a>
213 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]214 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
215 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
216 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
217 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
218 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
219 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
220 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]221 </ol>
222 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]223 <li><a href="#int_libc">Standard C Library Intrinsics</a>
224 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]225 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
226 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
227 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
228 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
229 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]230 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
231 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
232 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]233 </ol>
234 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]235 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]236 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]237 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]238 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
239 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
240 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]241 </ol>
242 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]243 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
244 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]245 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
246 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
247 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
248 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
249 <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]250 <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]251 </ol>
252 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]253 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]254 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]255 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]256 <ol>
257 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]258 </ol>
259 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]260 <li><a href="#int_atomics">Atomic intrinsics</a>
261 <ol>
262 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
263 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
264 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
265 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
266 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
267 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
268 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
269 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
270 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
271 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
272 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
273 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
274 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
275 </ol>
276 </li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]277 <li><a href="#int_memorymarkers">Memory Use Markers</a>
278 <ol>
279 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
280 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
281 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
282 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
283 </ol>
284 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]285 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]286 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]287 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]288 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]289 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]290 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]291 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]292 '<tt>llvm.trap</tt>' Intrinsic</a></li>
293 <li><a href="#int_stackprotector">
294 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]295 <li><a href="#int_objectsize">
296 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]297 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]298 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]299 </ol>
300 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]301</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]302
303<div class="doc_author">
304 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
305 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]306</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]307
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]308<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]309<div class="doc_section"> <a name="abstract">Abstract </a></div>
310<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]311
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]312<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]313
314<p>This document is a reference manual for the LLVM assembly language. LLVM is
315 a Static Single Assignment (SSA) based representation that provides type
316 safety, low-level operations, flexibility, and the capability of representing
317 'all' high-level languages cleanly. It is the common code representation
318 used throughout all phases of the LLVM compilation strategy.</p>
319
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]320</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]321
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]322<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]323<div class="doc_section"> <a name="introduction">Introduction</a> </div>
324<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]325
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]326<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]327
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]328<p>The LLVM code representation is designed to be used in three different forms:
329 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
330 for fast loading by a Just-In-Time compiler), and as a human readable
331 assembly language representation. This allows LLVM to provide a powerful
332 intermediate representation for efficient compiler transformations and
333 analysis, while providing a natural means to debug and visualize the
334 transformations. The three different forms of LLVM are all equivalent. This
335 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]336
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]337<p>The LLVM representation aims to be light-weight and low-level while being
338 expressive, typed, and extensible at the same time. It aims to be a
339 "universal IR" of sorts, by being at a low enough level that high-level ideas
340 may be cleanly mapped to it (similar to how microprocessors are "universal
341 IR's", allowing many source languages to be mapped to them). By providing
342 type information, LLVM can be used as the target of optimizations: for
343 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]344 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]345 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]346
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]347</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]348
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]349<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]350<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]351
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]352<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]353
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]354<p>It is important to note that this document describes 'well formed' LLVM
355 assembly language. There is a difference between what the parser accepts and
356 what is considered 'well formed'. For example, the following instruction is
357 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]358
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]359<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]360<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]361%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]362</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]363</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]364
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]365<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
366 LLVM infrastructure provides a verification pass that may be used to verify
367 that an LLVM module is well formed. This pass is automatically run by the
368 parser after parsing input assembly and by the optimizer before it outputs
369 bitcode. The violations pointed out by the verifier pass indicate bugs in
370 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]371
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]372</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]373
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]374<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]375
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]376<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]377<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]378<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]379
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]380<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]381
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]382<p>LLVM identifiers come in two basic types: global and local. Global
383 identifiers (functions, global variables) begin with the <tt>'@'</tt>
384 character. Local identifiers (register names, types) begin with
385 the <tt>'%'</tt> character. Additionally, there are three different formats
386 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]387
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]388<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]389 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]390 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
391 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
392 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
393 other characters in their names can be surrounded with quotes. Special
394 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
395 ASCII code for the character in hexadecimal. In this way, any character
396 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]397
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]398 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]399 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]400
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]401 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]402 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]403</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]404
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]405<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]406 don't need to worry about name clashes with reserved words, and the set of
407 reserved words may be expanded in the future without penalty. Additionally,
408 unnamed identifiers allow a compiler to quickly come up with a temporary
409 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]410
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]411<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]412 languages. There are keywords for different opcodes
413 ('<tt><a href="#i_add">add</a></tt>',
414 '<tt><a href="#i_bitcast">bitcast</a></tt>',
415 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
416 ('<tt><a href="#t_void">void</a></tt>',
417 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
418 reserved words cannot conflict with variable names, because none of them
419 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]420
421<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]422 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]423
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]424<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]425
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]426<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]427<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]428%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]429</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]430</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]431
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]432<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]433
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]434<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]435<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]436%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]437</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]438</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]439
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]440<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]441
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]442<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]443<pre>
Gabor Greifec58f752009-10-28 13:05:07 +0000[diff] [blame]444%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
445%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]446%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]447</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]448</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]449
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]450<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
451 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]452
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]453<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]454 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]455 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]456
457 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]458 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]459
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]460 <li>Unnamed temporaries are numbered sequentially</li>
461</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]462
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]463<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]464 demonstrating instructions, we will follow an instruction with a comment that
465 defines the type and name of value produced. Comments are shown in italic
466 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]467
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]468</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]469
470<!-- *********************************************************************** -->
471<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
472<!-- *********************************************************************** -->
473
474<!-- ======================================================================= -->
475<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
476</div>
477
478<div class="doc_text">
479
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]480<p>LLVM programs are composed of "Module"s, each of which is a translation unit
481 of the input programs. Each module consists of functions, global variables,
482 and symbol table entries. Modules may be combined together with the LLVM
483 linker, which merges function (and global variable) definitions, resolves
484 forward declarations, and merges symbol table entries. Here is an example of
485 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]486
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]487<div class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]488<pre>
489<i>; Declare the string constant as a global constant.</i>
490<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]491
492<i>; External declaration of the puts function</i>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]493<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]494
495<i>; Definition of main function</i>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]496define i32 @main() { <i>; i32()* </i>
497 <i>; Convert [13 x i8]* to i8 *...</i>
498 %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]499
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]500 <i>; Call puts function to write out the string to stdout.</i>
501 <a href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]502 <a href="#i_ret">ret</a> i32 0<br>}
503
504<i>; Named metadata</i>
505!1 = metadata !{i32 41}
506!foo = !{!1, null}
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]507</pre>
508</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]509
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]510<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]511 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]512 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]513 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
514 "<tt>foo"</tt>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]515
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]516<p>In general, a module is made up of a list of global values, where both
517 functions and global variables are global values. Global values are
518 represented by a pointer to a memory location (in this case, a pointer to an
519 array of char, and a pointer to a function), and have one of the
520 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]521
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]522</div>
523
524<!-- ======================================================================= -->
525<div class="doc_subsection">
526 <a name="linkage">Linkage Types</a>
527</div>
528
529<div class="doc_text">
530
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]531<p>All Global Variables and Functions have one of the following types of
532 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]533
534<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]535 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]536 <dd>Global values with private linkage are only directly accessible by objects
537 in the current module. In particular, linking code into a module with an
538 private global value may cause the private to be renamed as necessary to
539 avoid collisions. Because the symbol is private to the module, all
540 references can be updated. This doesn't show up in any symbol table in the
541 object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]542
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]543 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]544 <dd>Similar to private, but the symbol is passed through the assembler and
Chris Lattnere1eaf912009-08-24 04:32:16 +0000[diff] [blame]545 removed by the linker after evaluation. Note that (unlike private
546 symbols) linker_private symbols are subject to coalescing by the linker:
547 weak symbols get merged and redefinitions are rejected. However, unlike
548 normal strong symbols, they are removed by the linker from the final
549 linked image (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]550
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]551 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]552 <dd>Similar to private, but the value shows as a local symbol
553 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
554 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]555
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]556 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]557 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]558 into the object file corresponding to the LLVM module. They exist to
559 allow inlining and other optimizations to take place given knowledge of
560 the definition of the global, which is known to be somewhere outside the
561 module. Globals with <tt>available_externally</tt> linkage are allowed to
562 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
563 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]564
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]565 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]566 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]567 the same name when linkage occurs. This can be used to implement
568 some forms of inline functions, templates, or other code which must be
569 generated in each translation unit that uses it, but where the body may
570 be overridden with a more definitive definition later. Unreferenced
571 <tt>linkonce</tt> globals are allowed to be discarded. Note that
572 <tt>linkonce</tt> linkage does not actually allow the optimizer to
573 inline the body of this function into callers because it doesn't know if
574 this definition of the function is the definitive definition within the
575 program or whether it will be overridden by a stronger definition.
576 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
577 linkage.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]578
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]579 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]580 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
581 <tt>linkonce</tt> linkage, except that unreferenced globals with
582 <tt>weak</tt> linkage may not be discarded. This is used for globals that
583 are declared "weak" in C source code.</dd>
584
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]585 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]586 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
587 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
588 global scope.
589 Symbols with "<tt>common</tt>" linkage are merged in the same way as
590 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]591 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]592 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]593 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
594 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]595
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]596
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]597 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]598 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]599 pointer to array type. When two global variables with appending linkage
600 are linked together, the two global arrays are appended together. This is
601 the LLVM, typesafe, equivalent of having the system linker append together
602 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]603
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]604 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]605 <dd>The semantics of this linkage follow the ELF object file model: the symbol
606 is weak until linked, if not linked, the symbol becomes null instead of
607 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]608
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]609 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
610 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]611 <dd>Some languages allow differing globals to be merged, such as two functions
612 with different semantics. Other languages, such as <tt>C++</tt>, ensure
613 that only equivalent globals are ever merged (the "one definition rule" -
614 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
615 and <tt>weak_odr</tt> linkage types to indicate that the global will only
616 be merged with equivalent globals. These linkage types are otherwise the
617 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]618
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]619 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]620 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]621 visible, meaning that it participates in linkage and can be used to
622 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]623</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]624
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]625<p>The next two types of linkage are targeted for Microsoft Windows platform
626 only. They are designed to support importing (exporting) symbols from (to)
627 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]628
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]629<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]630 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]631 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]632 or variable via a global pointer to a pointer that is set up by the DLL
633 exporting the symbol. On Microsoft Windows targets, the pointer name is
634 formed by combining <code>__imp_</code> and the function or variable
635 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]636
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]637 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]638 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]639 pointer to a pointer in a DLL, so that it can be referenced with the
640 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
641 name is formed by combining <code>__imp_</code> and the function or
642 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]643</dl>
644
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]645<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
646 another module defined a "<tt>.LC0</tt>" variable and was linked with this
647 one, one of the two would be renamed, preventing a collision. Since
648 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
649 declarations), they are accessible outside of the current module.</p>
650
651<p>It is illegal for a function <i>declaration</i> to have any linkage type
652 other than "externally visible", <tt>dllimport</tt>
653 or <tt>extern_weak</tt>.</p>
654
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]655<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]656 or <tt>weak_odr</tt> linkages.</p>
657
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]658</div>
659
660<!-- ======================================================================= -->
661<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]662 <a name="callingconv">Calling Conventions</a>
663</div>
664
665<div class="doc_text">
666
667<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]668 and <a href="#i_invoke">invokes</a> can all have an optional calling
669 convention specified for the call. The calling convention of any pair of
670 dynamic caller/callee must match, or the behavior of the program is
671 undefined. The following calling conventions are supported by LLVM, and more
672 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]673
674<dl>
675 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]676 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]677 specified) matches the target C calling conventions. This calling
678 convention supports varargs function calls and tolerates some mismatch in
679 the declared prototype and implemented declaration of the function (as
680 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]681
682 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]683 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]684 (e.g. by passing things in registers). This calling convention allows the
685 target to use whatever tricks it wants to produce fast code for the
686 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]687 (Application Binary Interface).
688 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
689 when this convention is used.</a> This calling convention does not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]690 support varargs and requires the prototype of all callees to exactly match
691 the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]692
693 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]694 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]695 as possible under the assumption that the call is not commonly executed.
696 As such, these calls often preserve all registers so that the call does
697 not break any live ranges in the caller side. This calling convention
698 does not support varargs and requires the prototype of all callees to
699 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]700
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]701 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]702 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]703 target-specific calling conventions to be used. Target specific calling
704 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]705</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]706
707<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]708 support Pascal conventions or any other well-known target-independent
709 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]710
711</div>
712
713<!-- ======================================================================= -->
714<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]715 <a name="visibility">Visibility Styles</a>
716</div>
717
718<div class="doc_text">
719
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]720<p>All Global Variables and Functions have one of the following visibility
721 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]722
723<dl>
724 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]725 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]726 that the declaration is visible to other modules and, in shared libraries,
727 means that the declared entity may be overridden. On Darwin, default
728 visibility means that the declaration is visible to other modules. Default
729 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]730
731 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]732 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]733 object if they are in the same shared object. Usually, hidden visibility
734 indicates that the symbol will not be placed into the dynamic symbol
735 table, so no other module (executable or shared library) can reference it
736 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]737
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]738 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]739 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]740 the dynamic symbol table, but that references within the defining module
741 will bind to the local symbol. That is, the symbol cannot be overridden by
742 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]743</dl>
744
745</div>
746
747<!-- ======================================================================= -->
748<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]749 <a name="namedtypes">Named Types</a>
750</div>
751
752<div class="doc_text">
753
754<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]755 it easier to read the IR and make the IR more condensed (particularly when
756 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]757
758<div class="doc_code">
759<pre>
760%mytype = type { %mytype*, i32 }
761</pre>
762</div>
763
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]764<p>You may give a name to any <a href="#typesystem">type</a> except
765 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
766 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]767
768<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]769 and that you can therefore specify multiple names for the same type. This
770 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
771 uses structural typing, the name is not part of the type. When printing out
772 LLVM IR, the printer will pick <em>one name</em> to render all types of a
773 particular shape. This means that if you have code where two different
774 source types end up having the same LLVM type, that the dumper will sometimes
775 print the "wrong" or unexpected type. This is an important design point and
776 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]777
778</div>
779
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]780<!-- ======================================================================= -->
781<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]782 <a name="globalvars">Global Variables</a>
783</div>
784
785<div class="doc_text">
786
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]787<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]788 instead of run-time. Global variables may optionally be initialized, may
789 have an explicit section to be placed in, and may have an optional explicit
790 alignment specified. A variable may be defined as "thread_local", which
791 means that it will not be shared by threads (each thread will have a
792 separated copy of the variable). A variable may be defined as a global
793 "constant," which indicates that the contents of the variable
794 will <b>never</b> be modified (enabling better optimization, allowing the
795 global data to be placed in the read-only section of an executable, etc).
796 Note that variables that need runtime initialization cannot be marked
797 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]798
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]799<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
800 constant, even if the final definition of the global is not. This capability
801 can be used to enable slightly better optimization of the program, but
802 requires the language definition to guarantee that optimizations based on the
803 'constantness' are valid for the translation units that do not include the
804 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]805
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]806<p>As SSA values, global variables define pointer values that are in scope
807 (i.e. they dominate) all basic blocks in the program. Global variables
808 always define a pointer to their "content" type because they describe a
809 region of memory, and all memory objects in LLVM are accessed through
810 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]811
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]812<p>A global variable may be declared to reside in a target-specific numbered
813 address space. For targets that support them, address spaces may affect how
814 optimizations are performed and/or what target instructions are used to
815 access the variable. The default address space is zero. The address space
816 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]817
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]818<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]819 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]820
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]821<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]822 the alignment is set to zero, the alignment of the global is set by the
823 target to whatever it feels convenient. If an explicit alignment is
824 specified, the global is forced to have at least that much alignment. All
825 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]826
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]827<p>For example, the following defines a global in a numbered address space with
828 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]829
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]830<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]831<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]832@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]833</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]834</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]835
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]836</div>
837
838
839<!-- ======================================================================= -->
840<div class="doc_subsection">
841 <a name="functionstructure">Functions</a>
842</div>
843
844<div class="doc_text">
845
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]846<p>LLVM function definitions consist of the "<tt>define</tt>" keyord, an
847 optional <a href="#linkage">linkage type</a>, an optional
848 <a href="#visibility">visibility style</a>, an optional
849 <a href="#callingconv">calling convention</a>, a return type, an optional
850 <a href="#paramattrs">parameter attribute</a> for the return type, a function
851 name, a (possibly empty) argument list (each with optional
852 <a href="#paramattrs">parameter attributes</a>), optional
853 <a href="#fnattrs">function attributes</a>, an optional section, an optional
854 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
855 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]856
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]857<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
858 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]859 <a href="#visibility">visibility style</a>, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]860 <a href="#callingconv">calling convention</a>, a return type, an optional
861 <a href="#paramattrs">parameter attribute</a> for the return type, a function
862 name, a possibly empty list of arguments, an optional alignment, and an
863 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]864
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]865<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]866 (Control Flow Graph) for the function. Each basic block may optionally start
867 with a label (giving the basic block a symbol table entry), contains a list
868 of instructions, and ends with a <a href="#terminators">terminator</a>
869 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]870
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]871<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]872 executed on entrance to the function, and it is not allowed to have
873 predecessor basic blocks (i.e. there can not be any branches to the entry
874 block of a function). Because the block can have no predecessors, it also
875 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]876
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]877<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]878 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]879
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]880<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]881 the alignment is set to zero, the alignment of the function is set by the
882 target to whatever it feels convenient. If an explicit alignment is
883 specified, the function is forced to have at least that much alignment. All
884 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]885
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]886<h5>Syntax:</h5>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]887<div class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]888<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]889define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]890 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
891 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
892 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
893 [<a href="#gc">gc</a>] { ... }
894</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]895</div>
896
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]897</div>
898
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]899<!-- ======================================================================= -->
900<div class="doc_subsection">
901 <a name="aliasstructure">Aliases</a>
902</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]903
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]904<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]905
906<p>Aliases act as "second name" for the aliasee value (which can be either
907 function, global variable, another alias or bitcast of global value). Aliases
908 may have an optional <a href="#linkage">linkage type</a>, and an
909 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]910
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]911<h5>Syntax:</h5>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]912<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]913<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]914@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]915</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]916</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]917
918</div>
919
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]920<!-- ======================================================================= -->
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]921<div class="doc_subsection">
922 <a name="namedmetadatastructure">Named Metadata</a>
923</div>
924
925<div class="doc_text">
926
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]927<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
928 nodes</a> (but not metadata strings) and null are the only valid operands for
929 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]930
931<h5>Syntax:</h5>
932<div class="doc_code">
933<pre>
934!1 = metadata !{metadata !"one"}
935!name = !{null, !1}
936</pre>
937</div>
938
939</div>
940
941<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]942<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]943
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]944<div class="doc_text">
945
946<p>The return type and each parameter of a function type may have a set of
947 <i>parameter attributes</i> associated with them. Parameter attributes are
948 used to communicate additional information about the result or parameters of
949 a function. Parameter attributes are considered to be part of the function,
950 not of the function type, so functions with different parameter attributes
951 can have the same function type.</p>
952
953<p>Parameter attributes are simple keywords that follow the type specified. If
954 multiple parameter attributes are needed, they are space separated. For
955 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]956
957<div class="doc_code">
958<pre>
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]959declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]960declare i32 @atoi(i8 zeroext)
961declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]962</pre>
963</div>
964
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]965<p>Note that any attributes for the function result (<tt>nounwind</tt>,
966 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]967
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]968<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]969
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]970<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]971 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]972 <dd>This indicates to the code generator that the parameter or return value
973 should be zero-extended to a 32-bit value by the caller (for a parameter)
974 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]975
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]976 <dt><tt><b>signext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]977 <dd>This indicates to the code generator that the parameter or return value
978 should be sign-extended to a 32-bit value by the caller (for a parameter)
979 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]980
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]981 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]982 <dd>This indicates that this parameter or return value should be treated in a
983 special target-dependent fashion during while emitting code for a function
984 call or return (usually, by putting it in a register as opposed to memory,
985 though some targets use it to distinguish between two different kinds of
986 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]987
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]988 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]989 <dd>This indicates that the pointer parameter should really be passed by value
990 to the function. The attribute implies that a hidden copy of the pointee
991 is made between the caller and the callee, so the callee is unable to
992 modify the value in the callee. This attribute is only valid on LLVM
993 pointer arguments. It is generally used to pass structs and arrays by
994 value, but is also valid on pointers to scalars. The copy is considered
995 to belong to the caller not the callee (for example,
996 <tt><a href="#readonly">readonly</a></tt> functions should not write to
997 <tt>byval</tt> parameters). This is not a valid attribute for return
998 values. The byval attribute also supports specifying an alignment with
999 the align attribute. This has a target-specific effect on the code
1000 generator that usually indicates a desired alignment for the synthesized
1001 stack slot.</dd>
1002
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1003 <dt><tt><b>sret</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1004 <dd>This indicates that the pointer parameter specifies the address of a
1005 structure that is the return value of the function in the source program.
1006 This pointer must be guaranteed by the caller to be valid: loads and
1007 stores to the structure may be assumed by the callee to not to trap. This
1008 may only be applied to the first parameter. This is not a valid attribute
1009 for return values. </dd>
1010
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1011 <dt><tt><b>noalias</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1012 <dd>This indicates that the pointer does not alias any global or any other
1013 parameter. The caller is responsible for ensuring that this is the
1014 case. On a function return value, <tt>noalias</tt> additionally indicates
1015 that the pointer does not alias any other pointers visible to the
1016 caller. For further details, please see the discussion of the NoAlias
1017 response in
1018 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
1019 analysis</a>.</dd>
1020
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1021 <dt><tt><b>nocapture</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1022 <dd>This indicates that the callee does not make any copies of the pointer
1023 that outlive the callee itself. This is not a valid attribute for return
1024 values.</dd>
1025
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1026 <dt><tt><b>nest</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1027 <dd>This indicates that the pointer parameter can be excised using the
1028 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1029 attribute for return values.</dd>
1030</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1031
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1032</div>
1033
1034<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1035<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1036 <a name="gc">Garbage Collector Names</a>
1037</div>
1038
1039<div class="doc_text">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1040
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1041<p>Each function may specify a garbage collector name, which is simply a
1042 string:</p>
1043
1044<div class="doc_code">
1045<pre>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1046define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1047</pre>
1048</div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1049
1050<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1051 collector which will cause the compiler to alter its output in order to
1052 support the named garbage collection algorithm.</p>
1053
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1054</div>
1055
1056<!-- ======================================================================= -->
1057<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1058 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1059</div>
1060
1061<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1062
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1063<p>Function attributes are set to communicate additional information about a
1064 function. Function attributes are considered to be part of the function, not
1065 of the function type, so functions with different parameter attributes can
1066 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1067
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1068<p>Function attributes are simple keywords that follow the type specified. If
1069 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1070
1071<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1072<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1073define void @f() noinline { ... }
1074define void @f() alwaysinline { ... }
1075define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1076define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1077</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1078</div>
1079
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1080<dl>
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1081 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1082 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1083 the backend should forcibly align the stack pointer. Specify the
1084 desired alignment, which must be a power of two, in parentheses.
1085
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1086 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1087 <dd>This attribute indicates that the inliner should attempt to inline this
1088 function into callers whenever possible, ignoring any active inlining size
1089 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1090
Jakob Stoklund Olesen570a4a52010-02-06 01:16:28 +0000[diff] [blame]1091 <dt><tt><b>inlinehint</b></tt></dt>
1092 <dd>This attribute indicates that the source code contained a hint that inlining
1093 this function is desirable (such as the "inline" keyword in C/C++). It
1094 is just a hint; it imposes no requirements on the inliner.</dd>
1095
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1096 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1097 <dd>This attribute indicates that the inliner should never inline this
1098 function in any situation. This attribute may not be used together with
1099 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1100
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1101 <dt><tt><b>optsize</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1102 <dd>This attribute suggests that optimization passes and code generator passes
1103 make choices that keep the code size of this function low, and otherwise
1104 do optimizations specifically to reduce code size.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1105
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1106 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1107 <dd>This function attribute indicates that the function never returns
1108 normally. This produces undefined behavior at runtime if the function
1109 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1110
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1111 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1112 <dd>This function attribute indicates that the function never returns with an
1113 unwind or exceptional control flow. If the function does unwind, its
1114 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1115
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1116 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1117 <dd>This attribute indicates that the function computes its result (or decides
1118 to unwind an exception) based strictly on its arguments, without
1119 dereferencing any pointer arguments or otherwise accessing any mutable
1120 state (e.g. memory, control registers, etc) visible to caller functions.
1121 It does not write through any pointer arguments
1122 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1123 changes any state visible to callers. This means that it cannot unwind
1124 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1125 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1126
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1127 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1128 <dd>This attribute indicates that the function does not write through any
1129 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1130 arguments) or otherwise modify any state (e.g. memory, control registers,
1131 etc) visible to caller functions. It may dereference pointer arguments
1132 and read state that may be set in the caller. A readonly function always
1133 returns the same value (or unwinds an exception identically) when called
1134 with the same set of arguments and global state. It cannot unwind an
1135 exception by calling the <tt>C++</tt> exception throwing methods, but may
1136 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1137
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1138 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1139 <dd>This attribute indicates that the function should emit a stack smashing
1140 protector. It is in the form of a "canary"&mdash;a random value placed on
1141 the stack before the local variables that's checked upon return from the
1142 function to see if it has been overwritten. A heuristic is used to
1143 determine if a function needs stack protectors or not.<br>
1144<br>
1145 If a function that has an <tt>ssp</tt> attribute is inlined into a
1146 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1147 function will have an <tt>ssp</tt> attribute.</dd>
1148
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1149 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1150 <dd>This attribute indicates that the function should <em>always</em> emit a
1151 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1152 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1153<br>
1154 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1155 function that doesn't have an <tt>sspreq</tt> attribute or which has
1156 an <tt>ssp</tt> attribute, then the resulting function will have
1157 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1158
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1159 <dt><tt><b>noredzone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1160 <dd>This attribute indicates that the code generator should not use a red
1161 zone, even if the target-specific ABI normally permits it.</dd>
1162
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1163 <dt><tt><b>noimplicitfloat</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1164 <dd>This attributes disables implicit floating point instructions.</dd>
1165
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1166 <dt><tt><b>naked</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1167 <dd>This attribute disables prologue / epilogue emission for the function.
1168 This can have very system-specific consequences.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1169</dl>
1170
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1171</div>
1172
1173<!-- ======================================================================= -->
1174<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1175 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1176</div>
1177
1178<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1179
1180<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1181 the GCC "file scope inline asm" blocks. These blocks are internally
1182 concatenated by LLVM and treated as a single unit, but may be separated in
1183 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1184
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1185<div class="doc_code">
1186<pre>
1187module asm "inline asm code goes here"
1188module asm "more can go here"
1189</pre>
1190</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1191
1192<p>The strings can contain any character by escaping non-printable characters.
1193 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]1194 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1195
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1196<p>The inline asm code is simply printed to the machine code .s file when
1197 assembly code is generated.</p>
1198
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1199</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1200
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1201<!-- ======================================================================= -->
1202<div class="doc_subsection">
1203 <a name="datalayout">Data Layout</a>
1204</div>
1205
1206<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1207
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1208<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1209 data is to be laid out in memory. The syntax for the data layout is
1210 simply:</p>
1211
1212<div class="doc_code">
1213<pre>
1214target datalayout = "<i>layout specification</i>"
1215</pre>
1216</div>
1217
1218<p>The <i>layout specification</i> consists of a list of specifications
1219 separated by the minus sign character ('-'). Each specification starts with
1220 a letter and may include other information after the letter to define some
1221 aspect of the data layout. The specifications accepted are as follows:</p>
1222
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1223<dl>
1224 <dt><tt>E</tt></dt>
1225 <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]1226 bits with the most significance have the lowest address location.</dd>
1227
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1228 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1229 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1230 the bits with the least significance have the lowest address
1231 location.</dd>
1232
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1233 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1234 <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]1235 <i>preferred</i> alignments. All sizes are in bits. Specifying
1236 the <i>pref</i> alignment is optional. If omitted, the
1237 preceding <tt>:</tt> should be omitted too.</dd>
1238
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1239 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1240 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1241 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1242
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1243 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1244 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1245 <i>size</i>.</dd>
1246
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1247 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1248 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1249 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1250 (double).</dd>
1251
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1252 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1253 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1254 <i>size</i>.</dd>
1255
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1256 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1257 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1258 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1259
1260 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1261 <dd>This specifies a set of native integer widths for the target CPU
1262 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1263 "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]1264 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1265 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1266</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1267
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1268<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1269 default set of specifications which are then (possibly) overriden by the
1270 specifications in the <tt>datalayout</tt> keyword. The default specifications
1271 are given in this list:</p>
1272
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1273<ul>
1274 <li><tt>E</tt> - big endian</li>
1275 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1276 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1277 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1278 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1279 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1280 <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]1281 alignment of 64-bits</li>
1282 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1283 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1284 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1285 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1286 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1287 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1288</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1289
1290<p>When LLVM is determining the alignment for a given type, it uses the
1291 following rules:</p>
1292
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1293<ol>
1294 <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]1295 specification is used.</li>
1296
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1297 <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]1298 smallest integer type that is larger than the bitwidth of the sought type
1299 is used. If none of the specifications are larger than the bitwidth then
1300 the the largest integer type is used. For example, given the default
1301 specifications above, the i7 type will use the alignment of i8 (next
1302 largest) while both i65 and i256 will use the alignment of i64 (largest
1303 specified).</li>
1304
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1305 <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]1306 largest vector type that is smaller than the sought vector type will be
1307 used as a fall back. This happens because &lt;128 x double&gt; can be
1308 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1309</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1310
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1311</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1312
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1313<!-- ======================================================================= -->
1314<div class="doc_subsection">
1315 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1316</div>
1317
1318<div class="doc_text">
1319
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1320<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1321with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1322is undefined. Pointer values are associated with address ranges
1323according to the following rules:</p>
1324
1325<ul>
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1326 <li>A pointer value formed from a
1327 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1328 is associated with the addresses associated with the first operand
1329 of the <tt>getelementptr</tt>.</li>
1330 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1331 range of the variable's storage.</li>
1332 <li>The result value of an allocation instruction is associated with
1333 the address range of the allocated storage.</li>
1334 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1335 no address.</li>
1336 <li>A pointer value formed by an
1337 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1338 address ranges of all pointer values that contribute (directly or
1339 indirectly) to the computation of the pointer's value.</li>
1340 <li>The result value of a
1341 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1342 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1343 <li>An integer constant other than zero or a pointer value returned
1344 from a function not defined within LLVM may be associated with address
1345 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1346 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1347 allocated by mechanisms provided by LLVM.</li>
1348 </ul>
1349
1350<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1351<tt><a href="#i_load">load</a></tt> merely indicates the size and
1352alignment of the memory from which to load, as well as the
1353interpretation of the value. The first operand of a
1354<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1355and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1356
1357<p>Consequently, type-based alias analysis, aka TBAA, aka
1358<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1359LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1360additional information which specialized optimization passes may use
1361to implement type-based alias analysis.</p>
1362
1363</div>
1364
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1365<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1366<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1367<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1368
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1369<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1370
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1371<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1372 intermediate representation. Being typed enables a number of optimizations
1373 to be performed on the intermediate representation directly, without having
1374 to do extra analyses on the side before the transformation. A strong type
1375 system makes it easier to read the generated code and enables novel analyses
1376 and transformations that are not feasible to perform on normal three address
1377 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1378
1379</div>
1380
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1381<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1382<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1383Classifications</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1384
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1385<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1386
1387<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1388
1389<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1390 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1391 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1392 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1393 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1394 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1395 </tr>
1396 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1397 <td><a href="#t_floating">floating point</a></td>
1398 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1399 </tr>
1400 <tr>
1401 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1402 <td><a href="#t_integer">integer</a>,
1403 <a href="#t_floating">floating point</a>,
1404 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1405 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1406 <a href="#t_struct">structure</a>,
1407 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1408 <a href="#t_label">label</a>,
1409 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1410 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1411 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1412 <tr>
1413 <td><a href="#t_primitive">primitive</a></td>
1414 <td><a href="#t_label">label</a>,
1415 <a href="#t_void">void</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1416 <a href="#t_floating">floating point</a>,
1417 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1418 </tr>
1419 <tr>
1420 <td><a href="#t_derived">derived</a></td>
1421 <td><a href="#t_integer">integer</a>,
1422 <a href="#t_array">array</a>,
1423 <a href="#t_function">function</a>,
1424 <a href="#t_pointer">pointer</a>,
1425 <a href="#t_struct">structure</a>,
1426 <a href="#t_pstruct">packed structure</a>,
1427 <a href="#t_vector">vector</a>,
1428 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1429 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1430 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1431 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1432</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1433
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1434<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1435 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1436 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1437
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1438</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1439
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1440<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1441<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1442
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1443<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1444
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1445<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1446 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1447
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1448</div>
1449
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1450<!-- _______________________________________________________________________ -->
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1451<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1452
1453<div class="doc_text">
1454
1455<h5>Overview:</h5>
1456<p>The integer type is a very simple type that simply specifies an arbitrary
1457 bit width for the integer type desired. Any bit width from 1 bit to
1458 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1459
1460<h5>Syntax:</h5>
1461<pre>
1462 iN
1463</pre>
1464
1465<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1466 value.</p>
1467
1468<h5>Examples:</h5>
1469<table class="layout">
1470 <tr class="layout">
1471 <td class="left"><tt>i1</tt></td>
1472 <td class="left">a single-bit integer.</td>
1473 </tr>
1474 <tr class="layout">
1475 <td class="left"><tt>i32</tt></td>
1476 <td class="left">a 32-bit integer.</td>
1477 </tr>
1478 <tr class="layout">
1479 <td class="left"><tt>i1942652</tt></td>
1480 <td class="left">a really big integer of over 1 million bits.</td>
1481 </tr>
1482</table>
1483
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1484</div>
1485
1486<!-- _______________________________________________________________________ -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1487<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1488
1489<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1490
1491<table>
1492 <tbody>
1493 <tr><th>Type</th><th>Description</th></tr>
1494 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1495 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1496 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1497 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1498 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1499 </tbody>
1500</table>
1501
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1502</div>
1503
1504<!-- _______________________________________________________________________ -->
1505<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1506
1507<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1508
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1509<h5>Overview:</h5>
1510<p>The void type does not represent any value and has no size.</p>
1511
1512<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1513<pre>
1514 void
1515</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1516
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1517</div>
1518
1519<!-- _______________________________________________________________________ -->
1520<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1521
1522<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1523
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1524<h5>Overview:</h5>
1525<p>The label type represents code labels.</p>
1526
1527<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1528<pre>
1529 label
1530</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1531
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1532</div>
1533
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1534<!-- _______________________________________________________________________ -->
1535<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1536
1537<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1538
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1539<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1540<p>The metadata type represents embedded metadata. No derived types may be
1541 created from metadata except for <a href="#t_function">function</a>
1542 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1543
1544<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1545<pre>
1546 metadata
1547</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1548
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1549</div>
1550
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1551
1552<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1553<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1554
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1555<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1556
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1557<p>The real power in LLVM comes from the derived types in the system. This is
1558 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1559 useful types. Each of these types contain one or more element types which
1560 may be a primitive type, or another derived type. For example, it is
1561 possible to have a two dimensional array, using an array as the element type
1562 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1563
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1564</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1565
1566<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1567<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1568
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1569<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1570
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1571<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1572<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1573 sequentially in memory. The array type requires a size (number of elements)
1574 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1575
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1576<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1577<pre>
1578 [&lt;# elements&gt; x &lt;elementtype&gt;]
1579</pre>
1580
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1581<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1582 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1583
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1584<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1585<table class="layout">
1586 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1587 <td class="left"><tt>[40 x i32]</tt></td>
1588 <td class="left">Array of 40 32-bit integer values.</td>
1589 </tr>
1590 <tr class="layout">
1591 <td class="left"><tt>[41 x i32]</tt></td>
1592 <td class="left">Array of 41 32-bit integer values.</td>
1593 </tr>
1594 <tr class="layout">
1595 <td class="left"><tt>[4 x i8]</tt></td>
1596 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1597 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1598</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1599<p>Here are some examples of multidimensional arrays:</p>
1600<table class="layout">
1601 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1602 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1603 <td class="left">3x4 array of 32-bit integer values.</td>
1604 </tr>
1605 <tr class="layout">
1606 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1607 <td class="left">12x10 array of single precision floating point values.</td>
1608 </tr>
1609 <tr class="layout">
1610 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1611 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1612 </tr>
1613</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1614
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1615<p>There is no restriction on indexing beyond the end of the array implied by
1616 a static type (though there are restrictions on indexing beyond the bounds
1617 of an allocated object in some cases). This means that single-dimension
1618 'variable sized array' addressing can be implemented in LLVM with a zero
1619 length array type. An implementation of 'pascal style arrays' in LLVM could
1620 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1621
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1622</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1623
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1624<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1625<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1626
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1627<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1628
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1629<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1630<p>The function type can be thought of as a function signature. It consists of
1631 a return type and a list of formal parameter types. The return type of a
1632 function type is a scalar type, a void type, or a struct type. If the return
1633 type is a struct type then all struct elements must be of first class types,
1634 and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1635
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1636<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1637<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1638 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1639</pre>
1640
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1641<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]1642 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1643 which indicates that the function takes a variable number of arguments.
1644 Variable argument functions can access their arguments with
1645 the <a href="#int_varargs">variable argument handling intrinsic</a>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1646 functions. '<tt>&lt;returntype&gt;</tt>' is a any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1647 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1648
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1649<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1650<table class="layout">
1651 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1652 <td class="left"><tt>i32 (i32)</tt></td>
1653 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1654 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1655 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1656 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1657 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1658 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1659 an <tt>i16</tt> that should be sign extended and a
1660 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1661 <tt>float</tt>.
1662 </td>
1663 </tr><tr class="layout">
1664 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1665 <td class="left">A vararg function that takes at least one
1666 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1667 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1668 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1669 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1670 </tr><tr class="layout">
1671 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1672 <td class="left">A function taking an <tt>i32</tt>, returning a
1673 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1674 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1675 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1676</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1677
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1678</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1679
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1680<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1681<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1682
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1683<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1684
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1685<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1686<p>The structure type is used to represent a collection of data members together
1687 in memory. The packing of the field types is defined to match the ABI of the
1688 underlying processor. The elements of a structure may be any type that has a
1689 size.</p>
1690
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]1691<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1692 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1693 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1694 Structures in registers are accessed using the
1695 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1696 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1697<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1698<pre>
1699 { &lt;type list&gt; }
1700</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1701
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1702<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1703<table class="layout">
1704 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1705 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1706 <td class="left">A triple of three <tt>i32</tt> values</td>
1707 </tr><tr class="layout">
1708 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1709 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1710 second element is a <a href="#t_pointer">pointer</a> to a
1711 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1712 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1713 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1714</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1715
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1716</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1717
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1718<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1719<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1720</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1721
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1722<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1723
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1724<h5>Overview:</h5>
1725<p>The packed structure type is used to represent a collection of data members
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1726 together in memory. There is no padding between fields. Further, the
1727 alignment of a packed structure is 1 byte. The elements of a packed
1728 structure may be any type that has a size.</p>
1729
1730<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1731 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1732 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1733
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1734<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1735<pre>
1736 &lt; { &lt;type list&gt; } &gt;
1737</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1738
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1739<h5>Examples:</h5>
1740<table class="layout">
1741 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1742 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1743 <td class="left">A triple of three <tt>i32</tt> values</td>
1744 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1745 <td class="left">
1746<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1747 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1748 second element is a <a href="#t_pointer">pointer</a> to a
1749 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1750 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1751 </tr>
1752</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1753
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1754</div>
1755
1756<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1757<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1758
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1759<div class="doc_text">
1760
1761<h5>Overview:</h5>
1762<p>As in many languages, the pointer type represents a pointer or reference to
1763 another object, which must live in memory. Pointer types may have an optional
1764 address space attribute defining the target-specific numbered address space
1765 where the pointed-to object resides. The default address space is zero.</p>
1766
1767<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1768 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1769
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1770<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1771<pre>
1772 &lt;type&gt; *
1773</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1774
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1775<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1776<table class="layout">
1777 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1778 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1779 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1780 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1781 </tr>
1782 <tr class="layout">
1783 <td class="left"><tt>i32 (i32 *) *</tt></td>
1784 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1785 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1786 <tt>i32</tt>.</td>
1787 </tr>
1788 <tr class="layout">
1789 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1790 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1791 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1792 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1793</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1794
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1795</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1796
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1797<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1798<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1799
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1800<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1801
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1802<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1803<p>A vector type is a simple derived type that represents a vector of elements.
1804 Vector types are used when multiple primitive data are operated in parallel
1805 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]1806 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1807 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1808
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1809<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1810<pre>
1811 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1812</pre>
1813
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1814<p>The number of elements is a constant integer value; elementtype may be any
1815 integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1816
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1817<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1818<table class="layout">
1819 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1820 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1821 <td class="left">Vector of 4 32-bit integer values.</td>
1822 </tr>
1823 <tr class="layout">
1824 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1825 <td class="left">Vector of 8 32-bit floating-point values.</td>
1826 </tr>
1827 <tr class="layout">
1828 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1829 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1830 </tr>
1831</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1832
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1833</div>
1834
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1835<!-- _______________________________________________________________________ -->
1836<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1837<div class="doc_text">
1838
1839<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1840<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1841 corresponds (for example) to the C notion of a forward declared structure
1842 type. In LLVM, opaque types can eventually be resolved to any type (not just
1843 a structure type).</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1844
1845<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1846<pre>
1847 opaque
1848</pre>
1849
1850<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1851<table class="layout">
1852 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1853 <td class="left"><tt>opaque</tt></td>
1854 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1855 </tr>
1856</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1857
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1858</div>
1859
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1860<!-- ======================================================================= -->
1861<div class="doc_subsection">
1862 <a name="t_uprefs">Type Up-references</a>
1863</div>
1864
1865<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1866
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1867<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1868<p>An "up reference" allows you to refer to a lexically enclosing type without
1869 requiring it to have a name. For instance, a structure declaration may
1870 contain a pointer to any of the types it is lexically a member of. Example
1871 of up references (with their equivalent as named type declarations)
1872 include:</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1873
1874<pre>
Chris Lattner3060f5b2009-02-09 10:00:56 +0000[diff] [blame]1875 { \2 * } %x = type { %x* }
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1876 { \2 }* %y = type { %y }*
1877 \1* %z = type %z*
1878</pre>
1879
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1880<p>An up reference is needed by the asmprinter for printing out cyclic types
1881 when there is no declared name for a type in the cycle. Because the
1882 asmprinter does not want to print out an infinite type string, it needs a
1883 syntax to handle recursive types that have no names (all names are optional
1884 in llvm IR).</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1885
1886<h5>Syntax:</h5>
1887<pre>
1888 \&lt;level&gt;
1889</pre>
1890
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1891<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]1892
1893<h5>Examples:</h5>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1894<table class="layout">
1895 <tr class="layout">
1896 <td class="left"><tt>\1*</tt></td>
1897 <td class="left">Self-referential pointer.</td>
1898 </tr>
1899 <tr class="layout">
1900 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1901 <td class="left">Recursive structure where the upref refers to the out-most
1902 structure.</td>
1903 </tr>
1904</table>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1905
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1906</div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1907
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1908<!-- *********************************************************************** -->
1909<div class="doc_section"> <a name="constants">Constants</a> </div>
1910<!-- *********************************************************************** -->
1911
1912<div class="doc_text">
1913
1914<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1915 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1916
1917</div>
1918
1919<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1920<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1921
1922<div class="doc_text">
1923
1924<dl>
1925 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1926 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1927 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1928
1929 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1930 <dd>Standard integers (such as '4') are constants of
1931 the <a href="#t_integer">integer</a> type. Negative numbers may be used
1932 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1933
1934 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1935 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1936 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
1937 notation (see below). The assembler requires the exact decimal value of a
1938 floating-point constant. For example, the assembler accepts 1.25 but
1939 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1940 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1941
1942 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1943 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1944 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1945</dl>
1946
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1947<p>The one non-intuitive notation for constants is the hexadecimal form of
1948 floating point constants. For example, the form '<tt>double
1949 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
1950 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
1951 constants are required (and the only time that they are generated by the
1952 disassembler) is when a floating point constant must be emitted but it cannot
1953 be represented as a decimal floating point number in a reasonable number of
1954 digits. For example, NaN's, infinities, and other special values are
1955 represented in their IEEE hexadecimal format so that assembly and disassembly
1956 do not cause any bits to change in the constants.</p>
1957
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]1958<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1959 represented using the 16-digit form shown above (which matches the IEEE754
1960 representation for double); float values must, however, be exactly
1961 representable as IEE754 single precision. Hexadecimal format is always used
1962 for long double, and there are three forms of long double. The 80-bit format
1963 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
1964 The 128-bit format used by PowerPC (two adjacent doubles) is represented
1965 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
1966 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
1967 currently supported target uses this format. Long doubles will only work if
1968 they match the long double format on your target. All hexadecimal formats
1969 are big-endian (sign bit at the left).</p>
1970
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1971</div>
1972
1973<!-- ======================================================================= -->
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]1974<div class="doc_subsection">
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]1975<a name="aggregateconstants"></a> <!-- old anchor -->
1976<a name="complexconstants">Complex Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1977</div>
1978
1979<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1980
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]1981<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1982 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1983
1984<dl>
1985 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1986 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1987 type definitions (a comma separated list of elements, surrounded by braces
1988 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1989 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
1990 Structure constants must have <a href="#t_struct">structure type</a>, and
1991 the number and types of elements must match those specified by the
1992 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1993
1994 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1995 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1996 definitions (a comma separated list of elements, surrounded by square
1997 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
1998 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
1999 the number and types of elements must match those specified by the
2000 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2001
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2002 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2003 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2004 definitions (a comma separated list of elements, surrounded by
2005 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2006 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2007 have <a href="#t_vector">vector type</a>, and the number and types of
2008 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2009
2010 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2011 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2012 value to zero of <em>any</em> type, including scalar and aggregate types.
2013 This is often used to avoid having to print large zero initializers
2014 (e.g. for large arrays) and is always exactly equivalent to using explicit
2015 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2016
2017 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2018 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2019 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2020 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2021 be interpreted as part of the instruction stream, metadata is a place to
2022 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2023</dl>
2024
2025</div>
2026
2027<!-- ======================================================================= -->
2028<div class="doc_subsection">
2029 <a name="globalconstants">Global Variable and Function Addresses</a>
2030</div>
2031
2032<div class="doc_text">
2033
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2034<p>The addresses of <a href="#globalvars">global variables</a>
2035 and <a href="#functionstructure">functions</a> are always implicitly valid
2036 (link-time) constants. These constants are explicitly referenced when
2037 the <a href="#identifiers">identifier for the global</a> is used and always
2038 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2039 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2040
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2041<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2042<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2043@X = global i32 17
2044@Y = global i32 42
2045@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2046</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2047</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2048
2049</div>
2050
2051<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]2052<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2053<div class="doc_text">
2054
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2055<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]2056 indicates that the user of the value may receive an unspecified bit-pattern.
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2057 Undefined values may be of any type (other than label or void) and be used
2058 anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2059
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2060<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2061 program is well defined no matter what value is used. This gives the
2062 compiler more freedom to optimize. Here are some examples of (potentially
2063 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2064
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2065
2066<div class="doc_code">
2067<pre>
2068 %A = add %X, undef
2069 %B = sub %X, undef
2070 %C = xor %X, undef
2071Safe:
2072 %A = undef
2073 %B = undef
2074 %C = undef
2075</pre>
2076</div>
2077
2078<p>This is safe because all of the output bits are affected by the undef bits.
2079Any output bit can have a zero or one depending on the input bits.</p>
2080
2081<div class="doc_code">
2082<pre>
2083 %A = or %X, undef
2084 %B = and %X, undef
2085Safe:
2086 %A = -1
2087 %B = 0
2088Unsafe:
2089 %A = undef
2090 %B = undef
2091</pre>
2092</div>
2093
2094<p>These logical operations have bits that are not always affected by the input.
2095For example, if "%X" has a zero bit, then the output of the 'and' operation will
2096always be a zero, no matter what the corresponding bit from the undef is. As
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2097such, 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]2098However, it is safe to assume that all bits of the undef could be 0, and
2099optimize the and to 0. Likewise, it is safe to assume that all the bits of
2100the 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]2101-1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2102
2103<div class="doc_code">
2104<pre>
2105 %A = select undef, %X, %Y
2106 %B = select undef, 42, %Y
2107 %C = select %X, %Y, undef
2108Safe:
2109 %A = %X (or %Y)
2110 %B = 42 (or %Y)
2111 %C = %Y
2112Unsafe:
2113 %A = undef
2114 %B = undef
2115 %C = undef
2116</pre>
2117</div>
2118
2119<p>This set of examples show that undefined select (and conditional branch)
2120conditions can go "either way" but they have to come from one of the two
2121operands. In the %A example, if %X and %Y were both known to have a clear low
2122bit, then %A would have to have a cleared low bit. However, in the %C example,
2123the optimizer is allowed to assume that the undef operand could be the same as
2124%Y, allowing the whole select to be eliminated.</p>
2125
2126
2127<div class="doc_code">
2128<pre>
2129 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2130
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2131 %B = undef
2132 %C = xor %B, %B
2133
2134 %D = undef
2135 %E = icmp lt %D, 4
2136 %F = icmp gte %D, 4
2137
2138Safe:
2139 %A = undef
2140 %B = undef
2141 %C = undef
2142 %D = undef
2143 %E = undef
2144 %F = undef
2145</pre>
2146</div>
2147
2148<p>This example points out that two undef operands are not necessarily the same.
2149This can be surprising to people (and also matches C semantics) where they
2150assume that "X^X" is always zero, even if X is undef. This isn't true for a
2151number of reasons, but the short answer is that an undef "variable" can
2152arbitrarily change its value over its "live range". This is true because the
2153"variable" doesn't actually <em>have a live range</em>. Instead, the value is
2154logically read from arbitrary registers that happen to be around when needed,
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]2155so the value is not necessarily consistent over time. In fact, %A and %C need
Chris Lattner349eb412009-09-08 15:13:16 +0000[diff] [blame]2156to have the same semantics or the core LLVM "replace all uses with" concept
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2157would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2158
2159<div class="doc_code">
2160<pre>
2161 %A = fdiv undef, %X
2162 %B = fdiv %X, undef
2163Safe:
2164 %A = undef
2165b: unreachable
2166</pre>
2167</div>
2168
2169<p>These examples show the crucial difference between an <em>undefined
2170value</em> and <em>undefined behavior</em>. An undefined value (like undef) is
2171allowed to have an arbitrary bit-pattern. This means that the %A operation
2172can be constant folded to undef because the undef could be an SNaN, and fdiv is
2173not (currently) defined on SNaN's. However, in the second example, we can make
2174a more aggressive assumption: because the undef is allowed to be an arbitrary
2175value, 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]2176has <em>undefined behavior</em>, we are allowed to assume that the operation
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2177does not execute at all. This allows us to delete the divide and all code after
2178it: since the undefined operation "can't happen", the optimizer can assume that
2179it occurs in dead code.
2180</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2181
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2182<div class="doc_code">
2183<pre>
2184a: store undef -> %X
2185b: store %X -> undef
2186Safe:
2187a: &lt;deleted&gt;
2188b: unreachable
2189</pre>
2190</div>
2191
2192<p>These examples reiterate the fdiv example: a store "of" an undefined value
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2193can be assumed to not have any effect: we can assume that the value is
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2194overwritten with bits that happen to match what was already there. However, a
2195store "to" an undefined location could clobber arbitrary memory, therefore, it
2196has undefined behavior.</p>
2197
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2198</div>
2199
2200<!-- ======================================================================= -->
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]2201<div class="doc_subsection"><a name="blockaddress">Addresses of Basic
2202 Blocks</a></div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2203<div class="doc_text">
2204
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2205<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2206
2207<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2208 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2209 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2210
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2211<p>This value only has defined behavior when used as an operand to the
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2212 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction or for comparisons
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2213 against null. Pointer equality tests between labels addresses is undefined
2214 behavior - though, again, comparison against null is ok, and no label is
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]2215 equal to the null pointer. This may also be passed around as an opaque
2216 pointer sized value as long as the bits are not inspected. This allows
Chris Lattner3fd77ce2009-10-27 21:44:20 +0000[diff] [blame]2217 <tt>ptrtoint</tt> and arithmetic to be performed on these values so long as
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2218 the original value is reconstituted before the <tt>indirectbr</tt>.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2219
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]2220<p>Finally, some targets may provide defined semantics when
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2221 using the value as the operand to an inline assembly, but that is target
2222 specific.
2223 </p>
2224
2225</div>
2226
2227
2228<!-- ======================================================================= -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2229<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2230</div>
2231
2232<div class="doc_text">
2233
2234<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2235 to be used as constants. Constant expressions may be of
2236 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2237 operation that does not have side effects (e.g. load and call are not
2238 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2239
2240<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2241 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2242 <dd>Truncate a constant to another type. The bit size of CST must be larger
2243 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2244
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2245 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2246 <dd>Zero extend a constant to another type. The bit size of CST must be
2247 smaller or equal to the bit size of TYPE. Both types must be
2248 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2249
2250 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2251 <dd>Sign extend a constant to another type. The bit size of CST must be
2252 smaller or equal to the bit size of TYPE. Both types must be
2253 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2254
2255 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2256 <dd>Truncate a floating point constant to another floating point type. The
2257 size of CST must be larger than the size of TYPE. Both types must be
2258 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2259
2260 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2261 <dd>Floating point extend a constant to another type. The size of CST must be
2262 smaller or equal to the size of TYPE. Both types must be floating
2263 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2264
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]2265 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2266 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2267 constant. TYPE must be a scalar or vector integer type. CST must be of
2268 scalar or vector floating point type. Both CST and TYPE must be scalars,
2269 or vectors of the same number of elements. If the value won't fit in the
2270 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2271
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2272 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2273 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2274 constant. TYPE must be a scalar or vector integer type. CST must be of
2275 scalar or vector floating point type. Both CST and TYPE must be scalars,
2276 or vectors of the same number of elements. If the value won't fit in the
2277 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2278
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2279 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2280 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2281 constant. TYPE must be a scalar or vector floating point type. CST must be
2282 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2283 vectors of the same number of elements. If the value won't fit in the
2284 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2285
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2286 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2287 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2288 constant. TYPE must be a scalar or vector floating point type. CST must be
2289 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2290 vectors of the same number of elements. If the value won't fit in the
2291 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2292
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2293 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2294 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2295 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2296 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2297 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2298
2299 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2300 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2301 type. CST must be of integer type. The CST value is zero extended,
2302 truncated, or unchanged to make it fit in a pointer size. This one is
2303 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2304
2305 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2306 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2307 are the same as those for the <a href="#i_bitcast">bitcast
2308 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2309
2310 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]2311 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2312 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2313 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2314 instruction, the index list may have zero or more indexes, which are
2315 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2316
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2317 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2318 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2319
2320 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2321 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2322
2323 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2324 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2325
2326 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2327 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2328 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2329
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]2330 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2331 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2332 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2333
2334 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2335 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2336 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2337
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2338 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2339 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2340 be any of the <a href="#binaryops">binary</a>
2341 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2342 on operands are the same as those for the corresponding instruction
2343 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2344</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2345
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2346</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2347
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2348<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2349<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2350<!-- *********************************************************************** -->
2351
2352<!-- ======================================================================= -->
2353<div class="doc_subsection">
2354<a name="inlineasm">Inline Assembler Expressions</a>
2355</div>
2356
2357<div class="doc_text">
2358
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2359<p>LLVM supports inline assembler expressions (as opposed
2360 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2361 a special value. This value represents the inline assembler as a string
2362 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2363 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2364 expression has side effects, and a flag indicating whether the function
2365 containing the asm needs to align its stack conservatively. An example
2366 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2367
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2368<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2369<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2370i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2371</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2372</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2373
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2374<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2375 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2376 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2377
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2378<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2379<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2380%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]2381</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2382</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2383
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2384<p>Inline asms with side effects not visible in the constraint list must be
2385 marked as having side effects. This is done through the use of the
2386 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2387
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2388<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2389<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2390call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2391</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2392</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2393
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2394<p>In some cases inline asms will contain code that will not work unless the
2395 stack is aligned in some way, such as calls or SSE instructions on x86,
2396 yet will not contain code that does that alignment within the asm.
2397 The compiler should make conservative assumptions about what the asm might
2398 contain and should generate its usual stack alignment code in the prologue
2399 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2400
2401<div class="doc_code">
2402<pre>
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2403call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2404</pre>
2405</div>
2406
2407<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2408 first.</p>
2409
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2410<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2411 documented here. Constraints on what can be done (e.g. duplication, moving,
2412 etc need to be documented). This is probably best done by reference to
2413 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2414
2415</div>
2416
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2417<!-- ======================================================================= -->
2418<div class="doc_subsection"><a name="metadata">Metadata Nodes and Metadata
2419 Strings</a>
2420</div>
2421
2422<div class="doc_text">
2423
2424<p>LLVM IR allows metadata to be attached to instructions in the program that
2425 can convey extra information about the code to the optimizers and code
2426 generator. One example application of metadata is source-level debug
2427 information. There are two metadata primitives: strings and nodes. All
2428 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2429 preceding exclamation point ('<tt>!</tt>').</p>
2430
2431<p>A metadata string is a string surrounded by double quotes. It can contain
2432 any character by escaping non-printable characters with "\xx" where "xx" is
2433 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2434
2435<p>Metadata nodes are represented with notation similar to structure constants
2436 (a comma separated list of elements, surrounded by braces and preceded by an
2437 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2438 10}</tt>". Metadata nodes can have any values as their operand.</p>
2439
2440<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2441 metadata nodes, which can be looked up in the module symbol table. For
2442 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2443
2444</div>
2445
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2446
2447<!-- *********************************************************************** -->
2448<div class="doc_section">
2449 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2450</div>
2451<!-- *********************************************************************** -->
2452
2453<p>LLVM has a number of "magic" global variables that contain data that affect
2454code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2455of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2456section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2457by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2458
2459<!-- ======================================================================= -->
2460<div class="doc_subsection">
2461<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2462</div>
2463
2464<div class="doc_text">
2465
2466<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2467href="#linkage_appending">appending linkage</a>. This array contains a list of
2468pointers to global variables and functions which may optionally have a pointer
2469cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2470
2471<pre>
2472 @X = global i8 4
2473 @Y = global i32 123
2474
2475 @llvm.used = appending global [2 x i8*] [
2476 i8* @X,
2477 i8* bitcast (i32* @Y to i8*)
2478 ], section "llvm.metadata"
2479</pre>
2480
2481<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2482compiler, assembler, and linker are required to treat the symbol as if there is
2483a reference to the global that it cannot see. For example, if a variable has
2484internal linkage and no references other than that from the <tt>@llvm.used</tt>
2485list, it cannot be deleted. This is commonly used to represent references from
2486inline asms and other things the compiler cannot "see", and corresponds to
2487"attribute((used))" in GNU C.</p>
2488
2489<p>On some targets, the code generator must emit a directive to the assembler or
2490object file to prevent the assembler and linker from molesting the symbol.</p>
2491
2492</div>
2493
2494<!-- ======================================================================= -->
2495<div class="doc_subsection">
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2496<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2497</div>
2498
2499<div class="doc_text">
2500
2501<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2502<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2503touching the symbol. On targets that support it, this allows an intelligent
2504linker to optimize references to the symbol without being impeded as it would be
2505by <tt>@llvm.used</tt>.</p>
2506
2507<p>This is a rare construct that should only be used in rare circumstances, and
2508should not be exposed to source languages.</p>
2509
2510</div>
2511
2512<!-- ======================================================================= -->
2513<div class="doc_subsection">
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2514<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2515</div>
2516
2517<div class="doc_text">
2518
2519<p>TODO: Describe this.</p>
2520
2521</div>
2522
2523<!-- ======================================================================= -->
2524<div class="doc_subsection">
2525<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2526</div>
2527
2528<div class="doc_text">
2529
2530<p>TODO: Describe this.</p>
2531
2532</div>
2533
2534
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2535<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2536<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2537<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2538
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2539<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2540
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2541<p>The LLVM instruction set consists of several different classifications of
2542 instructions: <a href="#terminators">terminator
2543 instructions</a>, <a href="#binaryops">binary instructions</a>,
2544 <a href="#bitwiseops">bitwise binary instructions</a>,
2545 <a href="#memoryops">memory instructions</a>, and
2546 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2547
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2548</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2549
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2550<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2551<div class="doc_subsection"> <a name="terminators">Terminator
2552Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2553
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2554<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2555
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2556<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2557 in a program ends with a "Terminator" instruction, which indicates which
2558 block should be executed after the current block is finished. These
2559 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2560 control flow, not values (the one exception being the
2561 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2562
2563<p>There are six different terminator instructions: the
2564 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2565 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2566 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling21c346e2009-11-02 00:25:26 +0000[diff] [blame]2567 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2568 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2569 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2570 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2571
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2572</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2573
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2574<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2575<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2576Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2577
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2578<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2579
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2580<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2581<pre>
2582 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]2583 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2584</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2585
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2586<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2587<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2588 a value) from a function back to the caller.</p>
2589
2590<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2591 value and then causes control flow, and one that just causes control flow to
2592 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2593
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2594<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2595<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2596 return value. The type of the return value must be a
2597 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2598
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2599<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2600 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2601 value or a return value with a type that does not match its type, or if it
2602 has a void return type and contains a '<tt>ret</tt>' instruction with a
2603 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2604
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2605<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2606<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2607 the calling function's context. If the caller is a
2608 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2609 instruction after the call. If the caller was an
2610 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2611 the beginning of the "normal" destination block. If the instruction returns
2612 a value, that value shall set the call or invoke instruction's return
2613 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2614
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2615<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2616<pre>
2617 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2618 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]2619 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]2620</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2621
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2622</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2623<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2624<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2625
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2626<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2627
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2628<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2629<pre>
2630 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]2631</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2632
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2633<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2634<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2635 different basic block in the current function. There are two forms of this
2636 instruction, corresponding to a conditional branch and an unconditional
2637 branch.</p>
2638
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2639<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2640<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2641 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2642 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2643 target.</p>
2644
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2645<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2646<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2647 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2648 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2649 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2650
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2651<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2652<pre>
2653Test:
2654 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2655 br i1 %cond, label %IfEqual, label %IfUnequal
2656IfEqual:
2657 <a href="#i_ret">ret</a> i32 1
2658IfUnequal:
2659 <a href="#i_ret">ret</a> i32 0
2660</pre>
2661
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2662</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2663
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2664<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2665<div class="doc_subsubsection">
2666 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2667</div>
2668
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2669<div class="doc_text">
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2670
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2671<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2672<pre>
2673 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2674</pre>
2675
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2676<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2677<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]2678 several different places. It is a generalization of the '<tt>br</tt>'
2679 instruction, allowing a branch to occur to one of many possible
2680 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2681
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2682<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2683<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2684 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2685 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2686 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2687
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2688<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2689<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2690 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2691 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]2692 transferred to the corresponding destination; otherwise, control flow is
2693 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2694
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2695<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2696<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2697 <tt>switch</tt> instruction, this instruction may be code generated in
2698 different ways. For example, it could be generated as a series of chained
2699 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2700
2701<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2702<pre>
2703 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2704 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2705 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2706
2707 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2708 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2709
2710 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2711 switch i32 %val, label %otherwise [ i32 0, label %onzero
2712 i32 1, label %onone
2713 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2714</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2715
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2716</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2717
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2718
2719<!-- _______________________________________________________________________ -->
2720<div class="doc_subsubsection">
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2721 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2722</div>
2723
2724<div class="doc_text">
2725
2726<h5>Syntax:</h5>
2727<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2728 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]2729</pre>
2730
2731<h5>Overview:</h5>
2732
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2733<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2734 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2735 "<tt>address</tt>". Address must be derived from a <a
2736 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2737
2738<h5>Arguments:</h5>
2739
2740<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
2741 rest of the arguments indicate the full set of possible destinations that the
2742 address may point to. Blocks are allowed to occur multiple times in the
2743 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2744
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2745<p>This destination list is required so that dataflow analysis has an accurate
2746 understanding of the CFG.</p>
2747
2748<h5>Semantics:</h5>
2749
2750<p>Control transfers to the block specified in the address argument. All
2751 possible destination blocks must be listed in the label list, otherwise this
2752 instruction has undefined behavior. This implies that jumps to labels
2753 defined in other functions have undefined behavior as well.</p>
2754
2755<h5>Implementation:</h5>
2756
2757<p>This is typically implemented with a jump through a register.</p>
2758
2759<h5>Example:</h5>
2760<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]2761 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]2762</pre>
2763
2764</div>
2765
2766
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2767<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2768<div class="doc_subsubsection">
2769 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2770</div>
2771
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2772<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2773
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2774<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2775<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2776 &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]2777 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2778</pre>
2779
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2780<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2781<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2782 function, with the possibility of control flow transfer to either the
2783 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2784 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2785 control flow will return to the "normal" label. If the callee (or any
2786 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2787 instruction, control is interrupted and continued at the dynamically nearest
2788 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2789
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2790<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2791<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2792
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2793<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2794 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2795 convention</a> the call should use. If none is specified, the call
2796 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2797
2798 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2799 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2800 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2801
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2802 <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]2803 function value being invoked. In most cases, this is a direct function
2804 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2805 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2806
2807 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2808 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2809
2810 <li>'<tt>function args</tt>': argument list whose types match the function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2811 signature argument types. If the function signature indicates the
2812 function accepts a variable number of arguments, the extra arguments can
2813 be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2814
2815 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2816 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2817
2818 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2819 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2820
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2821 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2822 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2823 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2824</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2825
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2826<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2827<p>This instruction is designed to operate as a standard
2828 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2829 primary difference is that it establishes an association with a label, which
2830 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2831
2832<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2833 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2834 exception. Additionally, this is important for implementation of
2835 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2836
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2837<p>For the purposes of the SSA form, the definition of the value returned by the
2838 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2839 block to the "normal" label. If the callee unwinds then no return value is
2840 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]2841
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]2842<p>Note that the code generator does not yet completely support unwind, and
2843that the invoke/unwind semantics are likely to change in future versions.</p>
2844
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2845<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2846<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2847 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2848 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2849 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2850 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2851</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2852
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2853</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2854
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2855<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2856
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2857<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2858Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2859
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2860<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2861
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2862<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2863<pre>
2864 unwind
2865</pre>
2866
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2867<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2868<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2869 at the first callee in the dynamic call stack which used
2870 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
2871 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2872
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2873<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2874<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2875 immediately halt. The dynamic call stack is then searched for the
2876 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
2877 Once found, execution continues at the "exceptional" destination block
2878 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
2879 instruction in the dynamic call chain, undefined behavior results.</p>
2880
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]2881<p>Note that the code generator does not yet completely support unwind, and
2882that the invoke/unwind semantics are likely to change in future versions.</p>
2883
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2884</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2885
2886<!-- _______________________________________________________________________ -->
2887
2888<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2889Instruction</a> </div>
2890
2891<div class="doc_text">
2892
2893<h5>Syntax:</h5>
2894<pre>
2895 unreachable
2896</pre>
2897
2898<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2899<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2900 instruction is used to inform the optimizer that a particular portion of the
2901 code is not reachable. This can be used to indicate that the code after a
2902 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2903
2904<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2905<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2906
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2907</div>
2908
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2909<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2910<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2911
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2912<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2913
2914<p>Binary operators are used to do most of the computation in a program. They
2915 require two operands of the same type, execute an operation on them, and
2916 produce a single value. The operands might represent multiple data, as is
2917 the case with the <a href="#t_vector">vector</a> data type. The result value
2918 has the same type as its operands.</p>
2919
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2920<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2921
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2922</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2923
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2924<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2925<div class="doc_subsubsection">
2926 <a name="i_add">'<tt>add</tt>' Instruction</a>
2927</div>
2928
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2929<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2930
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2931<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2932<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2933 &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]2934 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2935 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2936 &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]2937</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2938
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2939<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2940<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2941
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2942<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2943<p>The two arguments to the '<tt>add</tt>' instruction must
2944 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2945 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2946
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2947<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2948<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2949
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2950<p>If the sum has unsigned overflow, the result returned is the mathematical
2951 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]2952
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2953<p>Because LLVM integers use a two's complement representation, this instruction
2954 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2955
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2956<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2957 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2958 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
2959 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2960
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2961<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2962<pre>
2963 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2964</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2965
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2966</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2967
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2968<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2969<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2970 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
2971</div>
2972
2973<div class="doc_text">
2974
2975<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2976<pre>
2977 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2978</pre>
2979
2980<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2981<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
2982
2983<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2984<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2985 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2986 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2987
2988<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2989<p>The value produced is the floating point sum of the two operands.</p>
2990
2991<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2992<pre>
2993 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
2994</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2995
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2996</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2997
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2998<!-- _______________________________________________________________________ -->
2999<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3000 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
3001</div>
3002
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3003<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3004
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3005<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3006<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3007 &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]3008 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3009 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3010 &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]3011</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3012
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3013<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3014<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3015 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3016
3017<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3018 '<tt>neg</tt>' instruction present in most other intermediate
3019 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3020
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3021<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3022<p>The two arguments to the '<tt>sub</tt>' instruction must
3023 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3024 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3025
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3026<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3027<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3028
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3029<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3030 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3031 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3032
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3033<p>Because LLVM integers use a two's complement representation, this instruction
3034 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3035
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3036<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3037 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3038 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
3039 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3040
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3041<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3042<pre>
3043 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3044 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3045</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3046
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3047</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3048
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3049<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3050<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3051 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
3052</div>
3053
3054<div class="doc_text">
3055
3056<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3057<pre>
3058 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3059</pre>
3060
3061<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3062<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3063 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3064
3065<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3066 '<tt>fneg</tt>' instruction present in most other intermediate
3067 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3068
3069<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3070<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3071 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3072 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3073
3074<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3075<p>The value produced is the floating point difference of the two operands.</p>
3076
3077<h5>Example:</h5>
3078<pre>
3079 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3080 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3081</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3082
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3083</div>
3084
3085<!-- _______________________________________________________________________ -->
3086<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3087 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
3088</div>
3089
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3090<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3091
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3092<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3093<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3094 &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]3095 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3096 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3097 &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]3098</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3099
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3100<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3101<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3102
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3103<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3104<p>The two arguments to the '<tt>mul</tt>' instruction must
3105 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3106 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3107
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3108<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3109<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3110
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3111<p>If the result of the multiplication has unsigned overflow, the result
3112 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3113 width of the result.</p>
3114
3115<p>Because LLVM integers use a two's complement representation, and the result
3116 is the same width as the operands, this instruction returns the correct
3117 result for both signed and unsigned integers. If a full product
3118 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3119 be sign-extended or zero-extended as appropriate to the width of the full
3120 product.</p>
3121
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3122<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3123 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3124 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
3125 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3126
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3127<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3128<pre>
3129 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3130</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3131
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3132</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3133
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3134<!-- _______________________________________________________________________ -->
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3135<div class="doc_subsubsection">
3136 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
3137</div>
3138
3139<div class="doc_text">
3140
3141<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3142<pre>
3143 &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]3144</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3145
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3146<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3147<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3148
3149<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3150<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3151 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3152 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3153
3154<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3155<p>The value produced is the floating point product of the two operands.</p>
3156
3157<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3158<pre>
3159 &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]3160</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3161
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3162</div>
3163
3164<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3165<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
3166</a></div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3167
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3168<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3169
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3170<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3171<pre>
3172 &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]3173</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3174
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3175<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3176<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3177
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3178<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3179<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3180 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3181 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3182
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3183<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3184<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3185
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3186<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3187 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3188
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3189<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3190
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3191<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3192<pre>
3193 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3194</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3195
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3196</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3197
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3198<!-- _______________________________________________________________________ -->
3199<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
3200</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3201
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3202<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3203
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3204<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3205<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3206 &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]3207 &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]3208</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3209
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3210<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3211<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3212
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3213<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3214<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3215 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3216 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3217
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3218<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3219<p>The value produced is the signed integer quotient of the two operands rounded
3220 towards zero.</p>
3221
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3222<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3223 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3224
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3225<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3226 undefined behavior; this is a rare case, but can occur, for example, by doing
3227 a 32-bit division of -2147483648 by -1.</p>
3228
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3229<p>If the <tt>exact</tt> keyword is present, the result value of the
3230 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
3231 would occur.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3232
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3233<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3234<pre>
3235 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3236</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3237
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3238</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3239
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3240<!-- _______________________________________________________________________ -->
3241<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3242Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3243
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3244<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3245
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3246<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3247<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3248 &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]3249</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3250
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3251<h5>Overview:</h5>
3252<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3253
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3254<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3255<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3256 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3257 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3258
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3259<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3260<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3261
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3262<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3263<pre>
3264 &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]3265</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3266
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3267</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3268
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3269<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3270<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3271</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3272
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3273<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3274
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3275<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3276<pre>
3277 &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]3278</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3279
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3280<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3281<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3282 division of its two arguments.</p>
3283
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3284<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3285<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3286 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3287 values. Both arguments must have identical types.</p>
3288
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3289<h5>Semantics:</h5>
3290<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3291 This instruction always performs an unsigned division to get the
3292 remainder.</p>
3293
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3294<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3295 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3296
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3297<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3298
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3299<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3300<pre>
3301 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3302</pre>
3303
3304</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3305
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3306<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3307<div class="doc_subsubsection">
3308 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3309</div>
3310
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3311<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3312
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3313<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3314<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3315 &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]3316</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3317
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3318<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3319<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3320 division of its two operands. This instruction can also take
3321 <a href="#t_vector">vector</a> versions of the values in which case the
3322 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3323
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3324<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3325<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3326 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3327 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3328
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3329<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3330<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3331 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3332 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3333 a value. For more information about the difference,
3334 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3335 Math Forum</a>. For a table of how this is implemented in various languages,
3336 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3337 Wikipedia: modulo operation</a>.</p>
3338
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3339<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3340 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3341
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3342<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3343 Overflow also leads to undefined behavior; this is a rare case, but can
3344 occur, for example, by taking the remainder of a 32-bit division of
3345 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3346 lets srem be implemented using instructions that return both the result of
3347 the division and the remainder.)</p>
3348
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3349<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3350<pre>
3351 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3352</pre>
3353
3354</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3355
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3356<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3357<div class="doc_subsubsection">
3358 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3359
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3360<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3361
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3362<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3363<pre>
3364 &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]3365</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3366
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3367<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3368<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3369 its two operands.</p>
3370
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3371<h5>Arguments:</h5>
3372<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3373 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3374 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3375
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3376<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3377<p>This instruction returns the <i>remainder</i> of a division. The remainder
3378 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3379
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3380<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3381<pre>
3382 &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]3383</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3384
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3385</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3386
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3387<!-- ======================================================================= -->
3388<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3389Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3390
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3391<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3392
3393<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3394 program. They are generally very efficient instructions and can commonly be
3395 strength reduced from other instructions. They require two operands of the
3396 same type, execute an operation on them, and produce a single value. The
3397 resulting value is the same type as its operands.</p>
3398
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3399</div>
3400
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3401<!-- _______________________________________________________________________ -->
3402<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3403Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3404
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3405<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3406
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3407<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3408<pre>
3409 &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]3410</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3411
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3412<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3413<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3414 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3415
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3416<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3417<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3418 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3419 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3420
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3421<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3422<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3423 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3424 is (statically or dynamically) negative or equal to or larger than the number
3425 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3426 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3427 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3428
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3429<h5>Example:</h5>
3430<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3431 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3432 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3433 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3434 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3435 &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]3436</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3437
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3438</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3439
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3440<!-- _______________________________________________________________________ -->
3441<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3442Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3443
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3444<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3445
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3446<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3447<pre>
3448 &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]3449</pre>
3450
3451<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3452<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3453 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3454
3455<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3456<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3457 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3458 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3459
3460<h5>Semantics:</h5>
3461<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3462 significant bits of the result will be filled with zero bits after the shift.
3463 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3464 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3465 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3466 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3467
3468<h5>Example:</h5>
3469<pre>
3470 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3471 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3472 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3473 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3474 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3475 &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]3476</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3477
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3478</div>
3479
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3480<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3481<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3482Instruction</a> </div>
3483<div class="doc_text">
3484
3485<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3486<pre>
3487 &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]3488</pre>
3489
3490<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3491<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3492 operand shifted to the right a specified number of bits with sign
3493 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3494
3495<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3496<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3497 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3498 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3499
3500<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3501<p>This instruction always performs an arithmetic shift right operation, The
3502 most significant bits of the result will be filled with the sign bit
3503 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3504 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3505 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3506 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3507
3508<h5>Example:</h5>
3509<pre>
3510 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3511 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3512 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3513 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3514 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3515 &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]3516</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3517
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3518</div>
3519
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3520<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3521<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3522Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3523
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3524<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3525
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3526<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3527<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3528 &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]3529</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3530
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3531<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3532<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3533 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3534
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3535<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3536<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3537 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3538 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3539
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3540<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3541<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3542
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3543<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3544 <tbody>
3545 <tr>
3546 <td>In0</td>
3547 <td>In1</td>
3548 <td>Out</td>
3549 </tr>
3550 <tr>
3551 <td>0</td>
3552 <td>0</td>
3553 <td>0</td>
3554 </tr>
3555 <tr>
3556 <td>0</td>
3557 <td>1</td>
3558 <td>0</td>
3559 </tr>
3560 <tr>
3561 <td>1</td>
3562 <td>0</td>
3563 <td>0</td>
3564 </tr>
3565 <tr>
3566 <td>1</td>
3567 <td>1</td>
3568 <td>1</td>
3569 </tr>
3570 </tbody>
3571</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3572
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3573<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3574<pre>
3575 &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]3576 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3577 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3578</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3579</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3580<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3581<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3582
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3583<div class="doc_text">
3584
3585<h5>Syntax:</h5>
3586<pre>
3587 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3588</pre>
3589
3590<h5>Overview:</h5>
3591<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3592 two operands.</p>
3593
3594<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3595<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3596 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3597 values. Both arguments must have identical types.</p>
3598
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3599<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3600<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3601
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3602<table border="1" cellspacing="0" cellpadding="4">
3603 <tbody>
3604 <tr>
3605 <td>In0</td>
3606 <td>In1</td>
3607 <td>Out</td>
3608 </tr>
3609 <tr>
3610 <td>0</td>
3611 <td>0</td>
3612 <td>0</td>
3613 </tr>
3614 <tr>
3615 <td>0</td>
3616 <td>1</td>
3617 <td>1</td>
3618 </tr>
3619 <tr>
3620 <td>1</td>
3621 <td>0</td>
3622 <td>1</td>
3623 </tr>
3624 <tr>
3625 <td>1</td>
3626 <td>1</td>
3627 <td>1</td>
3628 </tr>
3629 </tbody>
3630</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3631
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3632<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3633<pre>
3634 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3635 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3636 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3637</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3638
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3639</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3640
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3641<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3642<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3643Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3644
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3645<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3646
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3647<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3648<pre>
3649 &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]3650</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3651
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3652<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3653<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3654 its two operands. The <tt>xor</tt> is used to implement the "one's
3655 complement" operation, which is the "~" operator in C.</p>
3656
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3657<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3658<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3659 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3660 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3661
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3662<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3663<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3664
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3665<table border="1" cellspacing="0" cellpadding="4">
3666 <tbody>
3667 <tr>
3668 <td>In0</td>
3669 <td>In1</td>
3670 <td>Out</td>
3671 </tr>
3672 <tr>
3673 <td>0</td>
3674 <td>0</td>
3675 <td>0</td>
3676 </tr>
3677 <tr>
3678 <td>0</td>
3679 <td>1</td>
3680 <td>1</td>
3681 </tr>
3682 <tr>
3683 <td>1</td>
3684 <td>0</td>
3685 <td>1</td>
3686 </tr>
3687 <tr>
3688 <td>1</td>
3689 <td>1</td>
3690 <td>0</td>
3691 </tr>
3692 </tbody>
3693</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3694
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3695<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3696<pre>
3697 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3698 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3699 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3700 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3701</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3702
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3703</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3704
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3705<!-- ======================================================================= -->
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3706<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3707 <a name="vectorops">Vector Operations</a>
3708</div>
3709
3710<div class="doc_text">
3711
3712<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3713 target-independent manner. These instructions cover the element-access and
3714 vector-specific operations needed to process vectors effectively. While LLVM
3715 does directly support these vector operations, many sophisticated algorithms
3716 will want to use target-specific intrinsics to take full advantage of a
3717 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3718
3719</div>
3720
3721<!-- _______________________________________________________________________ -->
3722<div class="doc_subsubsection">
3723 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3724</div>
3725
3726<div class="doc_text">
3727
3728<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3729<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3730 &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]3731</pre>
3732
3733<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3734<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3735 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3736
3737
3738<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3739<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3740 of <a href="#t_vector">vector</a> type. The second operand is an index
3741 indicating the position from which to extract the element. The index may be
3742 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3743
3744<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3745<p>The result is a scalar of the same type as the element type of
3746 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3747 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3748 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3749
3750<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3751<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]3752 &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]3753</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3754
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3755</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3756
3757<!-- _______________________________________________________________________ -->
3758<div class="doc_subsubsection">
3759 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3760</div>
3761
3762<div class="doc_text">
3763
3764<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3765<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]3766 &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]3767</pre>
3768
3769<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3770<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3771 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3772
3773<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3774<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3775 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3776 whose type must equal the element type of the first operand. The third
3777 operand is an index indicating the position at which to insert the value.
3778 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3779
3780<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3781<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3782 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3783 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3784 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3785
3786<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3787<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]3788 &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]3789</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3790
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3791</div>
3792
3793<!-- _______________________________________________________________________ -->
3794<div class="doc_subsubsection">
3795 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3796</div>
3797
3798<div class="doc_text">
3799
3800<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3801<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3802 &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]3803</pre>
3804
3805<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3806<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3807 from two input vectors, returning a vector with the same element type as the
3808 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3809
3810<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3811<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3812 with types that match each other. The third argument is a shuffle mask whose
3813 element type is always 'i32'. The result of the instruction is a vector
3814 whose length is the same as the shuffle mask and whose element type is the
3815 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3816
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3817<p>The shuffle mask operand is required to be a constant vector with either
3818 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3819
3820<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3821<p>The elements of the two input vectors are numbered from left to right across
3822 both of the vectors. The shuffle mask operand specifies, for each element of
3823 the result vector, which element of the two input vectors the result element
3824 gets. The element selector may be undef (meaning "don't care") and the
3825 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3826
3827<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3828<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3829 &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]3830 &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]3831 &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]3832 &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]3833 &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]3834 &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]3835 &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]3836 &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]3837</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3838
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3839</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3840
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3841<!-- ======================================================================= -->
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3842<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3843 <a name="aggregateops">Aggregate Operations</a>
3844</div>
3845
3846<div class="doc_text">
3847
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3848<p>LLVM supports several instructions for working with aggregate values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3849
3850</div>
3851
3852<!-- _______________________________________________________________________ -->
3853<div class="doc_subsubsection">
3854 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3855</div>
3856
3857<div class="doc_text">
3858
3859<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3860<pre>
3861 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3862</pre>
3863
3864<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3865<p>The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3866 or array element from an aggregate value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3867
3868<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3869<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
3870 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3871 operands are constant indices to specify which value to extract in a similar
3872 manner as indices in a
3873 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3874
3875<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3876<p>The result is the value at the position in the aggregate specified by the
3877 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3878
3879<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3880<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]3881 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3882</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3883
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3884</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3885
3886<!-- _______________________________________________________________________ -->
3887<div class="doc_subsubsection">
3888 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3889</div>
3890
3891<div class="doc_text">
3892
3893<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3894<pre>
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]3895 &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]3896</pre>
3897
3898<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3899<p>The '<tt>insertvalue</tt>' instruction inserts a value into a struct field or
3900 array element in an aggregate.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3901
3902
3903<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3904<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
3905 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3906 second operand is a first-class value to insert. The following operands are
3907 constant indices indicating the position at which to insert the value in a
3908 similar manner as indices in a
3909 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
3910 value to insert must have the same type as the value identified by the
3911 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3912
3913<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3914<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
3915 that of <tt>val</tt> except that the value at the position specified by the
3916 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3917
3918<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3919<pre>
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]3920 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
3921 %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]3922</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3923
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3924</div>
3925
3926
3927<!-- ======================================================================= -->
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3928<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3929 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3930</div>
3931
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3932<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3933
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3934<p>A key design point of an SSA-based representation is how it represents
3935 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]3936 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3937 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3938
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3939</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3940
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3941<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3942<div class="doc_subsubsection">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3943 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3944</div>
3945
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3946<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3947
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3948<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3949<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3950 &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]3951</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3952
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3953<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3954<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3955 currently executing function, to be automatically released when this function
3956 returns to its caller. The object is always allocated in the generic address
3957 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3958
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3959<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3960<p>The '<tt>alloca</tt>' instruction
3961 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
3962 runtime stack, returning a pointer of the appropriate type to the program.
3963 If "NumElements" is specified, it is the number of elements allocated,
3964 otherwise "NumElements" is defaulted to be one. If a constant alignment is
3965 specified, the value result of the allocation is guaranteed to be aligned to
3966 at least that boundary. If not specified, or if zero, the target can choose
3967 to align the allocation on any convenient boundary compatible with the
3968 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3969
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3970<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3971
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3972<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]3973<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3974 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
3975 memory is automatically released when the function returns. The
3976 '<tt>alloca</tt>' instruction is commonly used to represent automatic
3977 variables that must have an address available. When the function returns
3978 (either with the <tt><a href="#i_ret">ret</a></tt>
3979 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
3980 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3981
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3982<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3983<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3984 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3985 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3986 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3987 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3988</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3989
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3990</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3991
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3992<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3993<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3994Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3995
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3996<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3997
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3998<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3999<pre>
4000 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
4001 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
4002</pre>
4003
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4004<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4005<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4006
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4007<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4008<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4009 from which to load. The pointer must point to
4010 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4011 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
4012 number or order of execution of this <tt>load</tt> with other
4013 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
4014 instructions. </p>
4015
4016<p>The optional constant "align" argument specifies the alignment of the
4017 operation (that is, the alignment of the memory address). A value of 0 or an
4018 omitted "align" argument means that the operation has the preferential
4019 alignment for the target. It is the responsibility of the code emitter to
4020 ensure that the alignment information is correct. Overestimating the
4021 alignment results in an undefined behavior. Underestimating the alignment may
4022 produce less efficient code. An alignment of 1 is always safe.</p>
4023
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4024<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4025<p>The location of memory pointed to is loaded. If the value being loaded is of
4026 scalar type then the number of bytes read does not exceed the minimum number
4027 of bytes needed to hold all bits of the type. For example, loading an
4028 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4029 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4030 is undefined if the value was not originally written using a store of the
4031 same type.</p>
4032
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4033<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4034<pre>
4035 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4036 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4037 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4038</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4039
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4040</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4041
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4042<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4043<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
4044Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4045
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]4046<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4047
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4048<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4049<pre>
4050 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]4051 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4052</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4053
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4054<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4055<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4056
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4057<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4058<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4059 and an address at which to store it. The type of the
4060 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4061 the <a href="#t_firstclass">first class</a> type of the
4062 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
4063 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
4064 or order of execution of this <tt>store</tt> with other
4065 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
4066 instructions.</p>
4067
4068<p>The optional constant "align" argument specifies the alignment of the
4069 operation (that is, the alignment of the memory address). A value of 0 or an
4070 omitted "align" argument means that the operation has the preferential
4071 alignment for the target. It is the responsibility of the code emitter to
4072 ensure that the alignment information is correct. Overestimating the
4073 alignment results in an undefined behavior. Underestimating the alignment may
4074 produce less efficient code. An alignment of 1 is always safe.</p>
4075
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4076<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4077<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4078 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4079 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4080 does not exceed the minimum number of bytes needed to hold all bits of the
4081 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4082 writing a value of a type like <tt>i20</tt> with a size that is not an
4083 integral number of bytes, it is unspecified what happens to the extra bits
4084 that do not belong to the type, but they will typically be overwritten.</p>
4085
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4086<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4087<pre>
4088 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4089 store i32 3, i32* %ptr <i>; yields {void}</i>
4090 %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]4091</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4092
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4093</div>
4094
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4095<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4096<div class="doc_subsubsection">
4097 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
4098</div>
4099
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4100<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4101
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4102<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4103<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4104 &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]4105 &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]4106</pre>
4107
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4108<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4109<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
4110 subelement of an aggregate data structure. It performs address calculation
4111 only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4112
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4113<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4114<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4115 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4116 elements of the aggregate object are indexed. The interpretation of each
4117 index is dependent on the type being indexed into. The first index always
4118 indexes the pointer value given as the first argument, the second index
4119 indexes a value of the type pointed to (not necessarily the value directly
4120 pointed to, since the first index can be non-zero), etc. The first type
4121 indexed into must be a pointer value, subsequent types can be arrays, vectors
4122 and structs. Note that subsequent types being indexed into can never be
4123 pointers, since that would require loading the pointer before continuing
4124 calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4125
4126<p>The type of each index argument depends on the type it is indexing into.
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4127 When indexing into a (optionally packed) structure, only <tt>i32</tt> integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4128 <b>constants</b> are allowed. When indexing into an array, pointer or
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4129 vector, integers of any width are allowed, and they are not required to be
4130 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4131
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4132<p>For example, let's consider a C code fragment and how it gets compiled to
4133 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4134
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4135<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4136<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4137struct RT {
4138 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4139 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4140 char C;
4141};
4142struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4143 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4144 double Y;
4145 struct RT Z;
4146};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4147
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4148int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4149 return &amp;s[1].Z.B[5][13];
4150}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4151</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4152</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4153
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4154<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4155
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4156<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4157<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]4158%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4159%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4160
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4161define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4162entry:
4163 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4164 ret i32* %reg
4165}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4166</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4167</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4168
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4169<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4170<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]4171 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4172 }</tt>' type, a structure. The second index indexes into the third element
4173 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4174 i8 }</tt>' type, another structure. The third index indexes into the second
4175 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4176 array. The two dimensions of the array are subscripted into, yielding an
4177 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4178 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4179
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4180<p>Note that it is perfectly legal to index partially through a structure,
4181 returning a pointer to an inner element. Because of this, the LLVM code for
4182 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4183
4184<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4185 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4186 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4187 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4188 %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]4189 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4190 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4191 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4192 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4193</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]4194
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4195<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman0a28d182009-07-29 16:00:30 +0000[diff] [blame]4196 <tt>getelementptr</tt> is undefined if the base pointer is not an
4197 <i>in bounds</i> address of an allocated object, or if any of the addresses
Dan Gohmanb255b882009-08-20 17:08:17 +0000[diff] [blame]4198 that would be formed by successive addition of the offsets implied by the
4199 indices to the base address with infinitely precise arithmetic are not an
4200 <i>in bounds</i> address of that allocated object.
Dan Gohman0a28d182009-07-29 16:00:30 +0000[diff] [blame]4201 The <i>in bounds</i> addresses for an allocated object are all the addresses
Dan Gohmanb255b882009-08-20 17:08:17 +0000[diff] [blame]4202 that point into the object, plus the address one byte past the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4203
4204<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4205 the base address with silently-wrapping two's complement arithmetic, and
4206 the result value of the <tt>getelementptr</tt> may be outside the object
4207 pointed to by the base pointer. The result value may not necessarily be
4208 used to access memory though, even if it happens to point into allocated
4209 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4210 section for more information.</p>
4211
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4212<p>The getelementptr instruction is often confusing. For some more insight into
4213 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4214
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4215<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4216<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4217 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4218 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4219 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4220 %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]4221 <i>; yields i8*:eptr</i>
4222 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]4223 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]4224 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4225</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4226
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4227</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4228
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4229<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4230<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4231</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4232
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4233<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4234
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4235<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4236 which all take a single operand and a type. They perform various bit
4237 conversions on the operand.</p>
4238
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4239</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4240
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4241<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4242<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4243 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4244</div>
4245<div class="doc_text">
4246
4247<h5>Syntax:</h5>
4248<pre>
4249 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4250</pre>
4251
4252<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4253<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4254 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4255
4256<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4257<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4258 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4259 size and type of the result, which must be
4260 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4261 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4262 allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4263
4264<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4265<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4266 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4267 source size must be larger than the destination size, <tt>trunc</tt> cannot
4268 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4269
4270<h5>Example:</h5>
4271<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4272 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4273 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4274 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4275</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4276
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4277</div>
4278
4279<!-- _______________________________________________________________________ -->
4280<div class="doc_subsubsection">
4281 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4282</div>
4283<div class="doc_text">
4284
4285<h5>Syntax:</h5>
4286<pre>
4287 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4288</pre>
4289
4290<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4291<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4292 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4293
4294
4295<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4296<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]4297 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4298 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]4299 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4300 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4301
4302<h5>Semantics:</h5>
4303<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]4304 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4305
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]4306<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]4307
4308<h5>Example:</h5>
4309<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4310 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4311 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4312</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4313
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4314</div>
4315
4316<!-- _______________________________________________________________________ -->
4317<div class="doc_subsubsection">
4318 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4319</div>
4320<div class="doc_text">
4321
4322<h5>Syntax:</h5>
4323<pre>
4324 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4325</pre>
4326
4327<h5>Overview:</h5>
4328<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4329
4330<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4331<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]4332 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4333 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]4334 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4335 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4336
4337<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4338<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4339 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4340 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4341
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4342<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]4343
4344<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4345<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4346 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4347 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4348</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4349
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4350</div>
4351
4352<!-- _______________________________________________________________________ -->
4353<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4354 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4355</div>
4356
4357<div class="doc_text">
4358
4359<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4360<pre>
4361 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4362</pre>
4363
4364<h5>Overview:</h5>
4365<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4366 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4367
4368<h5>Arguments:</h5>
4369<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4370 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4371 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]4372 <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]4373 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4374
4375<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4376<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4377 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4378 <a href="#t_floating">floating point</a> type. If the value cannot fit
4379 within the destination type, <tt>ty2</tt>, then the results are
4380 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4381
4382<h5>Example:</h5>
4383<pre>
4384 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4385 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4386</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4387
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4388</div>
4389
4390<!-- _______________________________________________________________________ -->
4391<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4392 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4393</div>
4394<div class="doc_text">
4395
4396<h5>Syntax:</h5>
4397<pre>
4398 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4399</pre>
4400
4401<h5>Overview:</h5>
4402<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]4403 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4404
4405<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4406<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4407 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4408 a <a href="#t_floating">floating point</a> type to cast it to. The source
4409 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4410
4411<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4412<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4413 <a href="#t_floating">floating point</a> type to a larger
4414 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4415 used to make a <i>no-op cast</i> because it always changes bits. Use
4416 <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]4417
4418<h5>Example:</h5>
4419<pre>
4420 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4421 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4422</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4423
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4424</div>
4425
4426<!-- _______________________________________________________________________ -->
4427<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]4428 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4429</div>
4430<div class="doc_text">
4431
4432<h5>Syntax:</h5>
4433<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4434 &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]4435</pre>
4436
4437<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4438<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4439 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4440
4441<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4442<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4443 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4444 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4445 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4446 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4447
4448<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4449<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4450 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4451 towards zero) unsigned integer value. If the value cannot fit
4452 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4453
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4454<h5>Example:</h5>
4455<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4456 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4457 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4458 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4459</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4460
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4461</div>
4462
4463<!-- _______________________________________________________________________ -->
4464<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4465 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4466</div>
4467<div class="doc_text">
4468
4469<h5>Syntax:</h5>
4470<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4471 &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]4472</pre>
4473
4474<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4475<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4476 <a href="#t_floating">floating point</a> <tt>value</tt> to
4477 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4478
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4479<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4480<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4481 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4482 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4483 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4484 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4485
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4486<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4487<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4488 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4489 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4490 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4491
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4492<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4493<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4494 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4495 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4496 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4497</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4498
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4499</div>
4500
4501<!-- _______________________________________________________________________ -->
4502<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4503 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4504</div>
4505<div class="doc_text">
4506
4507<h5>Syntax:</h5>
4508<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4509 &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]4510</pre>
4511
4512<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4513<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4514 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4515
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4516<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4517<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]4518 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4519 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4520 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4521 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4522
4523<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4524<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4525 integer quantity and converts it to the corresponding floating point
4526 value. If the value cannot fit in the floating point value, the results are
4527 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4528
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4529<h5>Example:</h5>
4530<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4531 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4532 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4533</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4534
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4535</div>
4536
4537<!-- _______________________________________________________________________ -->
4538<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4539 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4540</div>
4541<div class="doc_text">
4542
4543<h5>Syntax:</h5>
4544<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4545 &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]4546</pre>
4547
4548<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4549<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4550 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4551
4552<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4553<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]4554 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4555 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4556 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4557 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4558
4559<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4560<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4561 quantity and converts it to the corresponding floating point value. If the
4562 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4563
4564<h5>Example:</h5>
4565<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4566 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4567 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4568</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4569
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4570</div>
4571
4572<!-- _______________________________________________________________________ -->
4573<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4574 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4575</div>
4576<div class="doc_text">
4577
4578<h5>Syntax:</h5>
4579<pre>
4580 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4581</pre>
4582
4583<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4584<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4585 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4586
4587<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4588<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4589 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4590 <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]4591
4592<h5>Semantics:</h5>
4593<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4594 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4595 truncating or zero extending that value to the size of the integer type. If
4596 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4597 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4598 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4599 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4600
4601<h5>Example:</h5>
4602<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4603 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4604 %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]4605</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4606
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4607</div>
4608
4609<!-- _______________________________________________________________________ -->
4610<div class="doc_subsubsection">
4611 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4612</div>
4613<div class="doc_text">
4614
4615<h5>Syntax:</h5>
4616<pre>
4617 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4618</pre>
4619
4620<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4621<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4622 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4623
4624<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4625<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4626 value to cast, and a type to cast it to, which must be a
4627 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4628
4629<h5>Semantics:</h5>
4630<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4631 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4632 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4633 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4634 than the size of a pointer then a zero extension is done. If they are the
4635 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4636
4637<h5>Example:</h5>
4638<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4639 %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]4640 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4641 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4642</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4643
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4644</div>
4645
4646<!-- _______________________________________________________________________ -->
4647<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4648 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4649</div>
4650<div class="doc_text">
4651
4652<h5>Syntax:</h5>
4653<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4654 &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]4655</pre>
4656
4657<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4658<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4659 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4660
4661<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4662<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4663 non-aggregate first class value, and a type to cast it to, which must also be
4664 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4665 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4666 identical. If the source type is a pointer, the destination type must also be
4667 a pointer. This instruction supports bitwise conversion of vectors to
4668 integers and to vectors of other types (as long as they have the same
4669 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4670
4671<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4672<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4673 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4674 this conversion. The conversion is done as if the <tt>value</tt> had been
4675 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4676 be converted to other pointer types with this instruction. To convert
4677 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4678 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4679
4680<h5>Example:</h5>
4681<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4682 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4683 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4684 %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]4685</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4686
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4687</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4688
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4689<!-- ======================================================================= -->
4690<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4691
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4692<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4693
4694<p>The instructions in this category are the "miscellaneous" instructions, which
4695 defy better classification.</p>
4696
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4697</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4698
4699<!-- _______________________________________________________________________ -->
4700<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4701</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4702
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4703<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4704
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4705<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4706<pre>
4707 &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]4708</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4709
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4710<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4711<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4712 boolean values based on comparison of its two integer, integer vector, or
4713 pointer operands.</p>
4714
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4715<h5>Arguments:</h5>
4716<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4717 the condition code indicating the kind of comparison to perform. It is not a
4718 value, just a keyword. The possible condition code are:</p>
4719
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4720<ol>
4721 <li><tt>eq</tt>: equal</li>
4722 <li><tt>ne</tt>: not equal </li>
4723 <li><tt>ugt</tt>: unsigned greater than</li>
4724 <li><tt>uge</tt>: unsigned greater or equal</li>
4725 <li><tt>ult</tt>: unsigned less than</li>
4726 <li><tt>ule</tt>: unsigned less or equal</li>
4727 <li><tt>sgt</tt>: signed greater than</li>
4728 <li><tt>sge</tt>: signed greater or equal</li>
4729 <li><tt>slt</tt>: signed less than</li>
4730 <li><tt>sle</tt>: signed less or equal</li>
4731</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4732
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4733<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4734 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4735 typed. They must also be identical types.</p>
4736
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4737<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4738<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4739 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]4740 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]4741 result, as follows:</p>
4742
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4743<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4744 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4745 <tt>false</tt> otherwise. No sign interpretation is necessary or
4746 performed.</li>
4747
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4748 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4749 <tt>false</tt> otherwise. No sign interpretation is necessary or
4750 performed.</li>
4751
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4752 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4753 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4754
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4755 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4756 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4757 to <tt>op2</tt>.</li>
4758
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4759 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4760 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4761
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4762 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4763 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4764
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4765 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4766 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4767
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4768 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4769 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4770 to <tt>op2</tt>.</li>
4771
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4772 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4773 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4774
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4775 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4776 <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]4777</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4778
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4779<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4780 values are compared as if they were integers.</p>
4781
4782<p>If the operands are integer vectors, then they are compared element by
4783 element. The result is an <tt>i1</tt> vector with the same number of elements
4784 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4785
4786<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4787<pre>
4788 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4789 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4790 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4791 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4792 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4793 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4794</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4795
4796<p>Note that the code generator does not yet support vector types with
4797 the <tt>icmp</tt> instruction.</p>
4798
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4799</div>
4800
4801<!-- _______________________________________________________________________ -->
4802<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4803</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4804
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4805<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4806
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4807<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4808<pre>
4809 &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]4810</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4811
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4812<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4813<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4814 values based on comparison of its operands.</p>
4815
4816<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]4817(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4818
4819<p>If the operands are floating point vectors, then the result type is a vector
4820 of boolean with the same number of elements as the operands being
4821 compared.</p>
4822
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4823<h5>Arguments:</h5>
4824<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4825 the condition code indicating the kind of comparison to perform. It is not a
4826 value, just a keyword. The possible condition code are:</p>
4827
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4828<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4829 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4830 <li><tt>oeq</tt>: ordered and equal</li>
4831 <li><tt>ogt</tt>: ordered and greater than </li>
4832 <li><tt>oge</tt>: ordered and greater than or equal</li>
4833 <li><tt>olt</tt>: ordered and less than </li>
4834 <li><tt>ole</tt>: ordered and less than or equal</li>
4835 <li><tt>one</tt>: ordered and not equal</li>
4836 <li><tt>ord</tt>: ordered (no nans)</li>
4837 <li><tt>ueq</tt>: unordered or equal</li>
4838 <li><tt>ugt</tt>: unordered or greater than </li>
4839 <li><tt>uge</tt>: unordered or greater than or equal</li>
4840 <li><tt>ult</tt>: unordered or less than </li>
4841 <li><tt>ule</tt>: unordered or less than or equal</li>
4842 <li><tt>une</tt>: unordered or not equal</li>
4843 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4844 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4845</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4846
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4847<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4848 <i>unordered</i> means that either operand may be a QNAN.</p>
4849
4850<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
4851 a <a href="#t_floating">floating point</a> type or
4852 a <a href="#t_vector">vector</a> of floating point type. They must have
4853 identical types.</p>
4854
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4855<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4856<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4857 according to the condition code given as <tt>cond</tt>. If the operands are
4858 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]4859 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4860 follows:</p>
4861
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4862<ol>
4863 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4864
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4865 <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]4866 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4867
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4868 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4869 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
4870
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4871 <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]4872 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4873
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4874 <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]4875 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4876
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4877 <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]4878 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4879
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4880 <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]4881 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4882
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4883 <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]4884
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4885 <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]4886 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4887
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4888 <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]4889 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4890
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4891 <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]4892 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4893
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4894 <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]4895 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4896
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4897 <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]4898 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4899
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4900 <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]4901 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4902
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4903 <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]4904
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4905 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4906</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4907
4908<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4909<pre>
4910 &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]4911 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4912 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4913 &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]4914</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4915
4916<p>Note that the code generator does not yet support vector types with
4917 the <tt>fcmp</tt> instruction.</p>
4918
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4919</div>
4920
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4921<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4922<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4923 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4924</div>
4925
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4926<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4927
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4928<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4929<pre>
4930 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
4931</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4932
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4933<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4934<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
4935 SSA graph representing the function.</p>
4936
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4937<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4938<p>The type of the incoming values is specified with the first type field. After
4939 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
4940 one pair for each predecessor basic block of the current block. Only values
4941 of <a href="#t_firstclass">first class</a> type may be used as the value
4942 arguments to the PHI node. Only labels may be used as the label
4943 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4944
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4945<p>There must be no non-phi instructions between the start of a basic block and
4946 the PHI instructions: i.e. PHI instructions must be first in a basic
4947 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4948
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4949<p>For the purposes of the SSA form, the use of each incoming value is deemed to
4950 occur on the edge from the corresponding predecessor block to the current
4951 block (but after any definition of an '<tt>invoke</tt>' instruction's return
4952 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]4953
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4954<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4955<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4956 specified by the pair corresponding to the predecessor basic block that
4957 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4958
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4959<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4960<pre>
4961Loop: ; Infinite loop that counts from 0 on up...
4962 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4963 %nextindvar = add i32 %indvar, 1
4964 br label %Loop
4965</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4966
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4967</div>
4968
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4969<!-- _______________________________________________________________________ -->
4970<div class="doc_subsubsection">
4971 <a name="i_select">'<tt>select</tt>' Instruction</a>
4972</div>
4973
4974<div class="doc_text">
4975
4976<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4977<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4978 &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>
4979
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4980 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4981</pre>
4982
4983<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4984<p>The '<tt>select</tt>' instruction is used to choose one value based on a
4985 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4986
4987
4988<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4989<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
4990 values indicating the condition, and two values of the
4991 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
4992 vectors and the condition is a scalar, then entire vectors are selected, not
4993 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4994
4995<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4996<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
4997 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4998
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4999<p>If the condition is a vector of i1, then the value arguments must be vectors
5000 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5001
5002<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5003<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5004 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5005</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5006
5007<p>Note that the code generator does not yet support conditions
5008 with vector type.</p>
5009
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5010</div>
5011
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5012<!-- _______________________________________________________________________ -->
5013<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5014 <a name="i_call">'<tt>call</tt>' Instruction</a>
5015</div>
5016
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5017<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5018
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5019<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5020<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]5021 &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]5022</pre>
5023
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5024<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5025<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5026
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5027<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5028<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5029
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5030<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5031 <li>The optional "tail" marker indicates that the callee function does not
5032 access any allocas or varargs in the caller. Note that calls may be
5033 marked "tail" even if they do not occur before
5034 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5035 present, the function call is eligible for tail call optimization,
5036 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
5037 optimized into a jump</a>. As of this writing, the extra requirements for
5038 a call to actually be optimized are:
5039 <ul>
5040 <li>Caller and callee both have the calling
5041 convention <tt>fastcc</tt>.</li>
5042 <li>The call is in tail position (ret immediately follows call and ret
5043 uses value of call or is void).</li>
5044 <li>Option <tt>-tailcallopt</tt> is enabled,
5045 or <code>llvm::PerformTailCallOpt</code> is <code>true</code>.</li>
5046 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5047 constraints are met.</a></li>
5048 </ul>
5049 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5050
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5051 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5052 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5053 defaults to using C calling conventions. The calling convention of the
5054 call must match the calling convention of the target function, or else the
5055 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5056
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5057 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5058 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5059 '<tt>inreg</tt>' attributes are valid here.</li>
5060
5061 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5062 type of the return value. Functions that return no value are marked
5063 <tt><a href="#t_void">void</a></tt>.</li>
5064
5065 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5066 being invoked. The argument types must match the types implied by this
5067 signature. This type can be omitted if the function is not varargs and if
5068 the function type does not return a pointer to a function.</li>
5069
5070 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5071 be invoked. In most cases, this is a direct function invocation, but
5072 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5073 to function value.</li>
5074
5075 <li>'<tt>function args</tt>': argument list whose types match the function
5076 signature argument types. All arguments must be of
5077 <a href="#t_firstclass">first class</a> type. If the function signature
5078 indicates the function accepts a variable number of arguments, the extra
5079 arguments can be specified.</li>
5080
5081 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5082 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5083 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5084</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5085
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5086<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5087<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5088 a specified function, with its incoming arguments bound to the specified
5089 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5090 function, control flow continues with the instruction after the function
5091 call, and the return value of the function is bound to the result
5092 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5093
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5094<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5095<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]5096 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]5097 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
5098 %X = tail call i32 @foo() <i>; yields i32</i>
5099 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5100 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]5101
5102 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5103 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]5104 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5105 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]5106 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]5107 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5108</pre>
5109
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5110<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]5111standard C99 library as being the C99 library functions, and may perform
5112optimizations or generate code for them under that assumption. This is
5113something we'd like to change in the future to provide better support for
5114freestanding environments and non-C-based langauges.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5115
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5116</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5117
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5118<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5119<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]5120 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5121</div>
5122
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5123<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5124
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5125<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5126<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5127 &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]5128</pre>
5129
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5130<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5131<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5132 the "variable argument" area of a function call. It is used to implement the
5133 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5134
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5135<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5136<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5137 argument. It returns a value of the specified argument type and increments
5138 the <tt>va_list</tt> to point to the next argument. The actual type
5139 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5140
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5141<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5142<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5143 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5144 to the next argument. For more information, see the variable argument
5145 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5146
5147<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]5148 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5149 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5150
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5151<p><tt>va_arg</tt> is an LLVM instruction instead of
5152 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5153 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5154
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5155<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5156<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5157
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5158<p>Note that the code generator does not yet fully support va_arg on many
5159 targets. Also, it does not currently support va_arg with aggregate types on
5160 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]5161
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5162</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5163
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5164<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]5165<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
5166<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5167
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5168<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5169
5170<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5171 well known names and semantics and are required to follow certain
5172 restrictions. Overall, these intrinsics represent an extension mechanism for
5173 the LLVM language that does not require changing all of the transformations
5174 in LLVM when adding to the language (or the bitcode reader/writer, the
5175 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5176
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5177<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5178 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5179 begin with this prefix. Intrinsic functions must always be external
5180 functions: you cannot define the body of intrinsic functions. Intrinsic
5181 functions may only be used in call or invoke instructions: it is illegal to
5182 take the address of an intrinsic function. Additionally, because intrinsic
5183 functions are part of the LLVM language, it is required if any are added that
5184 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5185
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5186<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5187 family of functions that perform the same operation but on different data
5188 types. Because LLVM can represent over 8 million different integer types,
5189 overloading is used commonly to allow an intrinsic function to operate on any
5190 integer type. One or more of the argument types or the result type can be
5191 overloaded to accept any integer type. Argument types may also be defined as
5192 exactly matching a previous argument's type or the result type. This allows
5193 an intrinsic function which accepts multiple arguments, but needs all of them
5194 to be of the same type, to only be overloaded with respect to a single
5195 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5196
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5197<p>Overloaded intrinsics will have the names of its overloaded argument types
5198 encoded into its function name, each preceded by a period. Only those types
5199 which are overloaded result in a name suffix. Arguments whose type is matched
5200 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5201 can take an integer of any width and returns an integer of exactly the same
5202 integer width. This leads to a family of functions such as
5203 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5204 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5205 suffix is required. Because the argument's type is matched against the return
5206 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5207
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5208<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5209 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5210
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5211</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5212
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5213<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5214<div class="doc_subsection">
5215 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
5216</div>
5217
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5218<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5219
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5220<p>Variable argument support is defined in LLVM with
5221 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5222 intrinsic functions. These functions are related to the similarly named
5223 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5224
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5225<p>All of these functions operate on arguments that use a target-specific value
5226 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5227 not define what this type is, so all transformations should be prepared to
5228 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5229
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]5230<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]5231 instruction and the variable argument handling intrinsic functions are
5232 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5233
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5234<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5235<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5236define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5237 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5238 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5239 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5240 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5241
5242 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5243 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5244
5245 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5246 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5247 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5248 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5249 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5250
5251 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5252 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5253 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5254}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5255
5256declare void @llvm.va_start(i8*)
5257declare void @llvm.va_copy(i8*, i8*)
5258declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5259</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5260</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5261
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5262</div>
5263
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5264<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5265<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5266 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5267</div>
5268
5269
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5270<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5271
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5272<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5273<pre>
5274 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5275</pre>
5276
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5277<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5278<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5279 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]5280
5281<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5282<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]5283
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5284<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5285<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]5286 macro available in C. In a target-dependent way, it initializes
5287 the <tt>va_list</tt> element to which the argument points, so that the next
5288 call to <tt>va_arg</tt> will produce the first variable argument passed to
5289 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5290 need to know the last argument of the function as the compiler can figure
5291 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5292
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5293</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5294
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5295<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5296<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5297 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5298</div>
5299
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5300<div class="doc_text">
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5301
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5302<h5>Syntax:</h5>
5303<pre>
5304 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5305</pre>
5306
5307<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5308<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5309 which has been initialized previously
5310 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5311 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5312
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5313<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5314<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]5315
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5316<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5317<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]5318 macro available in C. In a target-dependent way, it destroys
5319 the <tt>va_list</tt> element to which the argument points. Calls
5320 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5321 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5322 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5323
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5324</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5325
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5326<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5327<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5328 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5329</div>
5330
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5331<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5332
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5333<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5334<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5335 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5336</pre>
5337
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5338<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5339<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5340 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5341
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5342<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5343<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]5344 The second argument is a pointer to a <tt>va_list</tt> element to copy
5345 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5346
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5347<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5348<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]5349 macro available in C. In a target-dependent way, it copies the
5350 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5351 element. This intrinsic is necessary because
5352 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5353 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5354
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5355</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5356
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5357<!-- ======================================================================= -->
5358<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5359 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5360</div>
5361
5362<div class="doc_text">
5363
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5364<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5365Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5366intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5367roots on the stack</a>, as well as garbage collector implementations that
5368require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5369barriers. Front-ends for type-safe garbage collected languages should generate
5370these intrinsics to make use of the LLVM garbage collectors. For more details,
5371see <a href="GarbageCollection.html">Accurate Garbage Collection with
5372LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5373
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5374<p>The garbage collection intrinsics only operate on objects in the generic
5375 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5376
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5377</div>
5378
5379<!-- _______________________________________________________________________ -->
5380<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5381 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5382</div>
5383
5384<div class="doc_text">
5385
5386<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5387<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5388 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5389</pre>
5390
5391<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]5392<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]5393 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5394
5395<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5396<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5397 root pointer. The second pointer (which must be either a constant or a
5398 global value address) contains the meta-data to be associated with the
5399 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5400
5401<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]5402<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]5403 location. At compile-time, the code generator generates information to allow
5404 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5405 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5406 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5407
5408</div>
5409
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5410<!-- _______________________________________________________________________ -->
5411<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5412 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5413</div>
5414
5415<div class="doc_text">
5416
5417<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5418<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5419 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5420</pre>
5421
5422<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5423<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5424 locations, allowing garbage collector implementations that require read
5425 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5426
5427<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5428<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]5429 allocated from the garbage collector. The first object is a pointer to the
5430 start of the referenced object, if needed by the language runtime (otherwise
5431 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5432
5433<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5434<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5435 instruction, but may be replaced with substantially more complex code by the
5436 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5437 may only be used in a function which <a href="#gc">specifies a GC
5438 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5439
5440</div>
5441
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5442<!-- _______________________________________________________________________ -->
5443<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5444 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5445</div>
5446
5447<div class="doc_text">
5448
5449<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5450<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5451 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5452</pre>
5453
5454<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5455<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5456 locations, allowing garbage collector implementations that require write
5457 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5458
5459<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5460<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]5461 object to store it to, and the third is the address of the field of Obj to
5462 store to. If the runtime does not require a pointer to the object, Obj may
5463 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5464
5465<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5466<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5467 instruction, but may be replaced with substantially more complex code by the
5468 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5469 may only be used in a function which <a href="#gc">specifies a GC
5470 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5471
5472</div>
5473
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5474<!-- ======================================================================= -->
5475<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5476 <a name="int_codegen">Code Generator Intrinsics</a>
5477</div>
5478
5479<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5480
5481<p>These intrinsics are provided by LLVM to expose special features that may
5482 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5483
5484</div>
5485
5486<!-- _______________________________________________________________________ -->
5487<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5488 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5489</div>
5490
5491<div class="doc_text">
5492
5493<h5>Syntax:</h5>
5494<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5495 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5496</pre>
5497
5498<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5499<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5500 target-specific value indicating the return address of the current function
5501 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5502
5503<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5504<p>The argument to this intrinsic indicates which function to return the address
5505 for. Zero indicates the calling function, one indicates its caller, etc.
5506 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5507
5508<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5509<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5510 indicating the return address of the specified call frame, or zero if it
5511 cannot be identified. The value returned by this intrinsic is likely to be
5512 incorrect or 0 for arguments other than zero, so it should only be used for
5513 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5514
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5515<p>Note that calling this intrinsic does not prevent function inlining or other
5516 aggressive transformations, so the value returned may not be that of the
5517 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5518
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5519</div>
5520
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5521<!-- _______________________________________________________________________ -->
5522<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5523 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5524</div>
5525
5526<div class="doc_text">
5527
5528<h5>Syntax:</h5>
5529<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5530 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5531</pre>
5532
5533<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5534<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5535 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5536
5537<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5538<p>The argument to this intrinsic indicates which function to return the frame
5539 pointer for. Zero indicates the calling function, one indicates its caller,
5540 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5541
5542<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5543<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5544 indicating the frame address of the specified call frame, or zero if it
5545 cannot be identified. The value returned by this intrinsic is likely to be
5546 incorrect or 0 for arguments other than zero, so it should only be used for
5547 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5548
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5549<p>Note that calling this intrinsic does not prevent function inlining or other
5550 aggressive transformations, so the value returned may not be that of the
5551 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5552
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5553</div>
5554
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5555<!-- _______________________________________________________________________ -->
5556<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5557 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5558</div>
5559
5560<div class="doc_text">
5561
5562<h5>Syntax:</h5>
5563<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5564 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5565</pre>
5566
5567<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5568<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5569 of the function stack, for use
5570 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5571 useful for implementing language features like scoped automatic variable
5572 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5573
5574<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5575<p>This intrinsic returns a opaque pointer value that can be passed
5576 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5577 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5578 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5579 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5580 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5581 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5582
5583</div>
5584
5585<!-- _______________________________________________________________________ -->
5586<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5587 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5588</div>
5589
5590<div class="doc_text">
5591
5592<h5>Syntax:</h5>
5593<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5594 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5595</pre>
5596
5597<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5598<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5599 the function stack to the state it was in when the
5600 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5601 executed. This is useful for implementing language features like scoped
5602 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5603
5604<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5605<p>See the description
5606 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5607
5608</div>
5609
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5610<!-- _______________________________________________________________________ -->
5611<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5612 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5613</div>
5614
5615<div class="doc_text">
5616
5617<h5>Syntax:</h5>
5618<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5619 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]5620</pre>
5621
5622<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5623<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5624 insert a prefetch instruction if supported; otherwise, it is a noop.
5625 Prefetches have no effect on the behavior of the program but can change its
5626 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5627
5628<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5629<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5630 specifier determining if the fetch should be for a read (0) or write (1),
5631 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5632 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5633 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5634
5635<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5636<p>This intrinsic does not modify the behavior of the program. In particular,
5637 prefetches cannot trap and do not produce a value. On targets that support
5638 this intrinsic, the prefetch can provide hints to the processor cache for
5639 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5640
5641</div>
5642
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5643<!-- _______________________________________________________________________ -->
5644<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5645 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5646</div>
5647
5648<div class="doc_text">
5649
5650<h5>Syntax:</h5>
5651<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5652 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5653</pre>
5654
5655<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5656<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5657 Counter (PC) in a region of code to simulators and other tools. The method
5658 is target specific, but it is expected that the marker will use exported
5659 symbols to transmit the PC of the marker. The marker makes no guarantees
5660 that it will remain with any specific instruction after optimizations. It is
5661 possible that the presence of a marker will inhibit optimizations. The
5662 intended use is to be inserted after optimizations to allow correlations of
5663 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5664
5665<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5666<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5667
5668<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5669<p>This intrinsic does not modify the behavior of the program. Backends that do
5670 not support this intrinisic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5671
5672</div>
5673
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5674<!-- _______________________________________________________________________ -->
5675<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5676 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5677</div>
5678
5679<div class="doc_text">
5680
5681<h5>Syntax:</h5>
5682<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5683 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5684</pre>
5685
5686<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5687<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5688 counter register (or similar low latency, high accuracy clocks) on those
5689 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5690 should map to RPCC. As the backing counters overflow quickly (on the order
5691 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5692
5693<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5694<p>When directly supported, reading the cycle counter should not modify any
5695 memory. Implementations are allowed to either return a application specific
5696 value or a system wide value. On backends without support, this is lowered
5697 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5698
5699</div>
5700
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5701<!-- ======================================================================= -->
5702<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5703 <a name="int_libc">Standard C Library Intrinsics</a>
5704</div>
5705
5706<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5707
5708<p>LLVM provides intrinsics for a few important standard C library functions.
5709 These intrinsics allow source-language front-ends to pass information about
5710 the alignment of the pointer arguments to the code generator, providing
5711 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5712
5713</div>
5714
5715<!-- _______________________________________________________________________ -->
5716<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5717 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5718</div>
5719
5720<div class="doc_text">
5721
5722<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5723<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
5724 integer bit width. Not all targets support all bit widths however.</p>
5725
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5726<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5727 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5728 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5729 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5730 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5731 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5732 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5733 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5734 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5735</pre>
5736
5737<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5738<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5739 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5740
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5741<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5742 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5743
5744<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5745<p>The first argument is a pointer to the destination, the second is a pointer
5746 to the source. The third argument is an integer argument specifying the
5747 number of bytes to copy, and the fourth argument is the alignment of the
5748 source and destination locations.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5749
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5750<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5751 then the caller guarantees that both the source and destination pointers are
5752 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5753
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5754<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5755<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5756 source location to the destination location, which are not allowed to
5757 overlap. It copies "len" bytes of memory over. If the argument is known to
5758 be aligned to some boundary, this can be specified as the fourth argument,
5759 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5760
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5761</div>
5762
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5763<!-- _______________________________________________________________________ -->
5764<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5765 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5766</div>
5767
5768<div class="doc_text">
5769
5770<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5771<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5772 width. Not all targets support all bit widths however.</p>
5773
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5774<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5775 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5776 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5777 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5778 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5779 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5780 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5781 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5782 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5783</pre>
5784
5785<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5786<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5787 source location to the destination location. It is similar to the
5788 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5789 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5790
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5791<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5792 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5793
5794<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5795<p>The first argument is a pointer to the destination, the second is a pointer
5796 to the source. The third argument is an integer argument specifying the
5797 number of bytes to copy, and the fourth argument is the alignment of the
5798 source and destination locations.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5799
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5800<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5801 then the caller guarantees that the source and destination pointers are
5802 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5803
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5804<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5805<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5806 source location to the destination location, which may overlap. It copies
5807 "len" bytes of memory over. If the argument is known to be aligned to some
5808 boundary, this can be specified as the fourth argument, otherwise it should
5809 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5810
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5811</div>
5812
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5813<!-- _______________________________________________________________________ -->
5814<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5815 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5816</div>
5817
5818<div class="doc_text">
5819
5820<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5821<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5822 width. Not all targets support all bit widths however.</p>
5823
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5824<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5825 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5826 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5827 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5828 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5829 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5830 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5831 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5832 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5833</pre>
5834
5835<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5836<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
5837 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5838
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5839<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
5840 intrinsic does not return a value, and takes an extra alignment argument.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5841
5842<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5843<p>The first argument is a pointer to the destination to fill, the second is the
5844 byte value to fill it with, the third argument is an integer argument
5845 specifying the number of bytes to fill, and the fourth argument is the known
5846 alignment of destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5847
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5848<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5849 then the caller guarantees that the destination pointer is aligned to that
5850 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5851
5852<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5853<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
5854 at the destination location. If the argument is known to be aligned to some
5855 boundary, this can be specified as the fourth argument, otherwise it should
5856 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5857
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5858</div>
5859
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5860<!-- _______________________________________________________________________ -->
5861<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5862 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5863</div>
5864
5865<div class="doc_text">
5866
5867<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5868<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
5869 floating point or vector of floating point type. Not all targets support all
5870 types however.</p>
5871
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5872<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5873 declare float @llvm.sqrt.f32(float %Val)
5874 declare double @llvm.sqrt.f64(double %Val)
5875 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5876 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5877 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5878</pre>
5879
5880<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5881<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
5882 returning the same value as the libm '<tt>sqrt</tt>' functions would.
5883 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
5884 behavior for negative numbers other than -0.0 (which allows for better
5885 optimization, because there is no need to worry about errno being
5886 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]5887
5888<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5889<p>The argument and return value are floating point numbers of the same
5890 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5891
5892<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5893<p>This function returns the sqrt of the specified operand if it is a
5894 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5895
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5896</div>
5897
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5898<!-- _______________________________________________________________________ -->
5899<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5900 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5901</div>
5902
5903<div class="doc_text">
5904
5905<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5906<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
5907 floating point or vector of floating point type. Not all targets support all
5908 types however.</p>
5909
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5910<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5911 declare float @llvm.powi.f32(float %Val, i32 %power)
5912 declare double @llvm.powi.f64(double %Val, i32 %power)
5913 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5914 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5915 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5916</pre>
5917
5918<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5919<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5920 specified (positive or negative) power. The order of evaluation of
5921 multiplications is not defined. When a vector of floating point type is
5922 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5923
5924<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5925<p>The second argument is an integer power, and the first is a value to raise to
5926 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5927
5928<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5929<p>This function returns the first value raised to the second power with an
5930 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5931
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5932</div>
5933
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5934<!-- _______________________________________________________________________ -->
5935<div class="doc_subsubsection">
5936 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5937</div>
5938
5939<div class="doc_text">
5940
5941<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5942<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5943 floating point or vector of floating point type. Not all targets support all
5944 types however.</p>
5945
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5946<pre>
5947 declare float @llvm.sin.f32(float %Val)
5948 declare double @llvm.sin.f64(double %Val)
5949 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5950 declare fp128 @llvm.sin.f128(fp128 %Val)
5951 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5952</pre>
5953
5954<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5955<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5956
5957<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5958<p>The argument and return value are floating point numbers of the same
5959 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5960
5961<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5962<p>This function returns the sine of the specified operand, returning the same
5963 values as the libm <tt>sin</tt> functions would, and handles error conditions
5964 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5965
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5966</div>
5967
5968<!-- _______________________________________________________________________ -->
5969<div class="doc_subsubsection">
5970 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5971</div>
5972
5973<div class="doc_text">
5974
5975<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5976<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5977 floating point or vector of floating point type. Not all targets support all
5978 types however.</p>
5979
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5980<pre>
5981 declare float @llvm.cos.f32(float %Val)
5982 declare double @llvm.cos.f64(double %Val)
5983 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5984 declare fp128 @llvm.cos.f128(fp128 %Val)
5985 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5986</pre>
5987
5988<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5989<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5990
5991<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5992<p>The argument and return value are floating point numbers of the same
5993 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5994
5995<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5996<p>This function returns the cosine of the specified operand, returning the same
5997 values as the libm <tt>cos</tt> functions would, and handles error conditions
5998 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5999
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6000</div>
6001
6002<!-- _______________________________________________________________________ -->
6003<div class="doc_subsubsection">
6004 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
6005</div>
6006
6007<div class="doc_text">
6008
6009<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6010<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6011 floating point or vector of floating point type. Not all targets support all
6012 types however.</p>
6013
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6014<pre>
6015 declare float @llvm.pow.f32(float %Val, float %Power)
6016 declare double @llvm.pow.f64(double %Val, double %Power)
6017 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6018 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6019 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6020</pre>
6021
6022<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6023<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6024 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6025
6026<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6027<p>The second argument is a floating point power, and the first is a value to
6028 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6029
6030<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6031<p>This function returns the first value raised to the second power, returning
6032 the same values as the libm <tt>pow</tt> functions would, and handles error
6033 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6034
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6035</div>
6036
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6037<!-- ======================================================================= -->
6038<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6039 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6040</div>
6041
6042<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6043
6044<p>LLVM provides intrinsics for a few important bit manipulation operations.
6045 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6046
6047</div>
6048
6049<!-- _______________________________________________________________________ -->
6050<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6051 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6052</div>
6053
6054<div class="doc_text">
6055
6056<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6057<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6058 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6059
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6060<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6061 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6062 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6063 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6064</pre>
6065
6066<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6067<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6068 values with an even number of bytes (positive multiple of 16 bits). These
6069 are useful for performing operations on data that is not in the target's
6070 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6071
6072<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6073<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6074 and low byte of the input i16 swapped. Similarly,
6075 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6076 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6077 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6078 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6079 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6080 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6081
6082</div>
6083
6084<!-- _______________________________________________________________________ -->
6085<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]6086 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6087</div>
6088
6089<div class="doc_text">
6090
6091<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6092<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]6093 width. Not all targets support all bit widths however.</p>
6094
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6095<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6096 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6097 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6098 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6099 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6100 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6101</pre>
6102
6103<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6104<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6105 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6106
6107<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6108<p>The only argument is the value to be counted. The argument may be of any
6109 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6110
6111<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6112<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]6113
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6114</div>
6115
6116<!-- _______________________________________________________________________ -->
6117<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6118 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6119</div>
6120
6121<div class="doc_text">
6122
6123<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6124<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
6125 integer bit width. Not all targets support all bit widths however.</p>
6126
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6127<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6128 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6129 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6130 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6131 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6132 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6133</pre>
6134
6135<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6136<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6137 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6138
6139<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6140<p>The only argument is the value to be counted. The argument may be of any
6141 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6142
6143<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6144<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
6145 zeros in a variable. If the src == 0 then the result is the size in bits of
6146 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6147
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6148</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6149
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6150<!-- _______________________________________________________________________ -->
6151<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6152 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6153</div>
6154
6155<div class="doc_text">
6156
6157<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6158<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
6159 integer bit width. Not all targets support all bit widths however.</p>
6160
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6161<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6162 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6163 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6164 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6165 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6166 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6167</pre>
6168
6169<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6170<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6171 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6172
6173<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6174<p>The only argument is the value to be counted. The argument may be of any
6175 integer type. The return type must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6176
6177<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6178<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
6179 zeros in a variable. If the src == 0 then the result is the size in bits of
6180 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6181
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6182</div>
6183
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6184<!-- ======================================================================= -->
6185<div class="doc_subsection">
6186 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
6187</div>
6188
6189<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6190
6191<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6192
6193</div>
6194
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6195<!-- _______________________________________________________________________ -->
6196<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6197 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6198</div>
6199
6200<div class="doc_text">
6201
6202<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6203<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]6204 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6205
6206<pre>
6207 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6208 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6209 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6210</pre>
6211
6212<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6213<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6214 a signed addition of the two arguments, and indicate whether an overflow
6215 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6216
6217<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6218<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]6219 be of integer types of any bit width, but they must have the same bit
6220 width. The second element of the result structure must be of
6221 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6222 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6223
6224<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6225<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6226 a signed addition of the two variables. They return a structure &mdash; the
6227 first element of which is the signed summation, and the second element of
6228 which is a bit specifying if the signed summation resulted in an
6229 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6230
6231<h5>Examples:</h5>
6232<pre>
6233 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6234 %sum = extractvalue {i32, i1} %res, 0
6235 %obit = extractvalue {i32, i1} %res, 1
6236 br i1 %obit, label %overflow, label %normal
6237</pre>
6238
6239</div>
6240
6241<!-- _______________________________________________________________________ -->
6242<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6243 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6244</div>
6245
6246<div class="doc_text">
6247
6248<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6249<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]6250 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6251
6252<pre>
6253 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6254 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6255 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6256</pre>
6257
6258<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6259<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6260 an unsigned addition of the two arguments, and indicate whether a carry
6261 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6262
6263<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6264<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]6265 be of integer types of any bit width, but they must have the same bit
6266 width. The second element of the result structure must be of
6267 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6268 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6269
6270<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6271<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6272 an unsigned addition of the two arguments. They return a structure &mdash;
6273 the first element of which is the sum, and the second element of which is a
6274 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6275
6276<h5>Examples:</h5>
6277<pre>
6278 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6279 %sum = extractvalue {i32, i1} %res, 0
6280 %obit = extractvalue {i32, i1} %res, 1
6281 br i1 %obit, label %carry, label %normal
6282</pre>
6283
6284</div>
6285
6286<!-- _______________________________________________________________________ -->
6287<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6288 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6289</div>
6290
6291<div class="doc_text">
6292
6293<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6294<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]6295 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6296
6297<pre>
6298 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6299 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6300 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6301</pre>
6302
6303<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6304<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6305 a signed subtraction of the two arguments, and indicate whether an overflow
6306 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6307
6308<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6309<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]6310 be of integer types of any bit width, but they must have the same bit
6311 width. The second element of the result structure must be of
6312 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6313 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6314
6315<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6316<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6317 a signed subtraction of the two arguments. They return a structure &mdash;
6318 the first element of which is the subtraction, and the second element of
6319 which is a bit specifying if the signed subtraction resulted in an
6320 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6321
6322<h5>Examples:</h5>
6323<pre>
6324 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6325 %sum = extractvalue {i32, i1} %res, 0
6326 %obit = extractvalue {i32, i1} %res, 1
6327 br i1 %obit, label %overflow, label %normal
6328</pre>
6329
6330</div>
6331
6332<!-- _______________________________________________________________________ -->
6333<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6334 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6335</div>
6336
6337<div class="doc_text">
6338
6339<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6340<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]6341 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6342
6343<pre>
6344 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6345 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6346 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6347</pre>
6348
6349<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6350<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6351 an unsigned subtraction of the two arguments, and indicate whether an
6352 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6353
6354<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6355<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]6356 be of integer types of any bit width, but they must have the same bit
6357 width. The second element of the result structure must be of
6358 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6359 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6360
6361<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6362<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6363 an unsigned subtraction of the two arguments. They return a structure &mdash;
6364 the first element of which is the subtraction, and the second element of
6365 which is a bit specifying if the unsigned subtraction resulted in an
6366 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6367
6368<h5>Examples:</h5>
6369<pre>
6370 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6371 %sum = extractvalue {i32, i1} %res, 0
6372 %obit = extractvalue {i32, i1} %res, 1
6373 br i1 %obit, label %overflow, label %normal
6374</pre>
6375
6376</div>
6377
6378<!-- _______________________________________________________________________ -->
6379<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6380 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6381</div>
6382
6383<div class="doc_text">
6384
6385<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6386<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]6387 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6388
6389<pre>
6390 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6391 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6392 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6393</pre>
6394
6395<h5>Overview:</h5>
6396
6397<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6398 a signed multiplication of the two arguments, and indicate whether an
6399 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6400
6401<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6402<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]6403 be of integer types of any bit width, but they must have the same bit
6404 width. The second element of the result structure must be of
6405 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6406 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6407
6408<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6409<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6410 a signed multiplication of the two arguments. They return a structure &mdash;
6411 the first element of which is the multiplication, and the second element of
6412 which is a bit specifying if the signed multiplication resulted in an
6413 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6414
6415<h5>Examples:</h5>
6416<pre>
6417 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6418 %sum = extractvalue {i32, i1} %res, 0
6419 %obit = extractvalue {i32, i1} %res, 1
6420 br i1 %obit, label %overflow, label %normal
6421</pre>
6422
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6423</div>
6424
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6425<!-- _______________________________________________________________________ -->
6426<div class="doc_subsubsection">
6427 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6428</div>
6429
6430<div class="doc_text">
6431
6432<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6433<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]6434 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6435
6436<pre>
6437 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6438 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6439 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6440</pre>
6441
6442<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6443<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6444 a unsigned multiplication of the two arguments, and indicate whether an
6445 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6446
6447<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6448<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]6449 be of integer types of any bit width, but they must have the same bit
6450 width. The second element of the result structure must be of
6451 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6452 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6453
6454<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6455<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6456 an unsigned multiplication of the two arguments. They return a structure
6457 &mdash; the first element of which is the multiplication, and the second
6458 element of which is a bit specifying if the unsigned multiplication resulted
6459 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6460
6461<h5>Examples:</h5>
6462<pre>
6463 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6464 %sum = extractvalue {i32, i1} %res, 0
6465 %obit = extractvalue {i32, i1} %res, 1
6466 br i1 %obit, label %overflow, label %normal
6467</pre>
6468
6469</div>
6470
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6471<!-- ======================================================================= -->
6472<div class="doc_subsection">
6473 <a name="int_debugger">Debugger Intrinsics</a>
6474</div>
6475
6476<div class="doc_text">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6477
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6478<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6479 prefix), are described in
6480 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6481 Level Debugging</a> document.</p>
6482
6483</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6484
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6485<!-- ======================================================================= -->
6486<div class="doc_subsection">
6487 <a name="int_eh">Exception Handling Intrinsics</a>
6488</div>
6489
6490<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6491
6492<p>The LLVM exception handling intrinsics (which all start with
6493 <tt>llvm.eh.</tt> prefix), are described in
6494 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6495 Handling</a> document.</p>
6496
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6497</div>
6498
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6499<!-- ======================================================================= -->
6500<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6501 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6502</div>
6503
6504<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6505
6506<p>This intrinsic makes it possible to excise one parameter, marked with
6507 the <tt>nest</tt> attribute, from a function. The result is a callable
6508 function pointer lacking the nest parameter - the caller does not need to
6509 provide a value for it. Instead, the value to use is stored in advance in a
6510 "trampoline", a block of memory usually allocated on the stack, which also
6511 contains code to splice the nest value into the argument list. This is used
6512 to implement the GCC nested function address extension.</p>
6513
6514<p>For example, if the function is
6515 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6516 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6517 follows:</p>
6518
6519<div class="doc_code">
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6520<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6521 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6522 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6523 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6524 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6525</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6526</div>
6527
6528<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6529 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6530
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6531</div>
6532
6533<!-- _______________________________________________________________________ -->
6534<div class="doc_subsubsection">
6535 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6536</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6537
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6538<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6539
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6540<h5>Syntax:</h5>
6541<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6542 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]6543</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6544
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6545<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6546<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6547 function pointer suitable for executing it.</p>
6548
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6549<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6550<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6551 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6552 sufficiently aligned block of memory; this memory is written to by the
6553 intrinsic. Note that the size and the alignment are target-specific - LLVM
6554 currently provides no portable way of determining them, so a front-end that
6555 generates this intrinsic needs to have some target-specific knowledge.
6556 The <tt>func</tt> argument must hold a function bitcast to
6557 an <tt>i8*</tt>.</p>
6558
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6559<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6560<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6561 dependent code, turning it into a function. A pointer to this function is
6562 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6563 function pointer type</a> before being called. The new function's signature
6564 is the same as that of <tt>func</tt> with any arguments marked with
6565 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6566 is allowed, and it must be of pointer type. Calling the new function is
6567 equivalent to calling <tt>func</tt> with the same argument list, but
6568 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6569 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6570 by <tt>tramp</tt> is modified, then the effect of any later call to the
6571 returned function pointer is undefined.</p>
6572
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6573</div>
6574
6575<!-- ======================================================================= -->
6576<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6577 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6578</div>
6579
6580<div class="doc_text">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6581
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6582<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6583 hardware constructs for atomic operations and memory synchronization. This
6584 provides an interface to the hardware, not an interface to the programmer. It
6585 is aimed at a low enough level to allow any programming models or APIs
6586 (Application Programming Interfaces) which need atomic behaviors to map
6587 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6588 hardware provides a "universal IR" for source languages, it also provides a
6589 starting point for developing a "universal" atomic operation and
6590 synchronization IR.</p>
6591
6592<p>These do <em>not</em> form an API such as high-level threading libraries,
6593 software transaction memory systems, atomic primitives, and intrinsic
6594 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6595 application libraries. The hardware interface provided by LLVM should allow
6596 a clean implementation of all of these APIs and parallel programming models.
6597 No one model or paradigm should be selected above others unless the hardware
6598 itself ubiquitously does so.</p>
6599
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6600</div>
6601
6602<!-- _______________________________________________________________________ -->
6603<div class="doc_subsubsection">
6604 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6605</div>
6606<div class="doc_text">
6607<h5>Syntax:</h5>
6608<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6609 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]6610</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6611
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6612<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6613<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6614 specific pairs of memory access types.</p>
6615
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6616<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6617<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6618 The first four arguments enables a specific barrier as listed below. The
6619 fith argument specifies that the barrier applies to io or device or uncached
6620 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6621
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6622<ul>
6623 <li><tt>ll</tt>: load-load barrier</li>
6624 <li><tt>ls</tt>: load-store barrier</li>
6625 <li><tt>sl</tt>: store-load barrier</li>
6626 <li><tt>ss</tt>: store-store barrier</li>
6627 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6628</ul>
6629
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6630<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6631<p>This intrinsic causes the system to enforce some ordering constraints upon
6632 the loads and stores of the program. This barrier does not
6633 indicate <em>when</em> any events will occur, it only enforces
6634 an <em>order</em> in which they occur. For any of the specified pairs of load
6635 and store operations (f.ex. load-load, or store-load), all of the first
6636 operations preceding the barrier will complete before any of the second
6637 operations succeeding the barrier begin. Specifically the semantics for each
6638 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6639
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6640<ul>
6641 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6642 after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6643 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6644 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6645 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6646 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6647 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6648 load after the barrier begins.</li>
6649</ul>
6650
6651<p>These semantics are applied with a logical "and" behavior when more than one
6652 is enabled in a single memory barrier intrinsic.</p>
6653
6654<p>Backends may implement stronger barriers than those requested when they do
6655 not support as fine grained a barrier as requested. Some architectures do
6656 not need all types of barriers and on such architectures, these become
6657 noops.</p>
6658
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6659<h5>Example:</h5>
6660<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]6661%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6662%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6663 store i32 4, %ptr
6664
6665%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6666 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6667 <i>; guarantee the above finishes</i>
6668 store i32 8, %ptr <i>; before this begins</i>
6669</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6670
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6671</div>
6672
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6673<!-- _______________________________________________________________________ -->
6674<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6675 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6676</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6677
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6678<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6679
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6680<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6681<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6682 any integer bit width and for different address spaces. Not all targets
6683 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6684
6685<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6686 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6687 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6688 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6689 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]6690</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6691
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6692<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6693<p>This loads a value in memory and compares it to a given value. If they are
6694 equal, it stores a new value into the memory.</p>
6695
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6696<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6697<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6698 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6699 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6700 this integer type. While any bit width integer may be used, targets may only
6701 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6702
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6703<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6704<p>This entire intrinsic must be executed atomically. It first loads the value
6705 in memory pointed to by <tt>ptr</tt> and compares it with the
6706 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6707 memory. The loaded value is yielded in all cases. This provides the
6708 equivalent of an atomic compare-and-swap operation within the SSA
6709 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6710
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6711<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6712<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]6713%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6714%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6715 store i32 4, %ptr
6716
6717%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6718%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6719 <i>; yields {i32}:result1 = 4</i>
6720%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6721%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6722
6723%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6724%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6725 <i>; yields {i32}:result2 = 8</i>
6726%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6727
6728%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6729</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6730
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6731</div>
6732
6733<!-- _______________________________________________________________________ -->
6734<div class="doc_subsubsection">
6735 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6736</div>
6737<div class="doc_text">
6738<h5>Syntax:</h5>
6739
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6740<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6741 integer bit width. Not all targets support all bit widths however.</p>
6742
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6743<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6744 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6745 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6746 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6747 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]6748</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6749
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6750<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6751<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6752 the value from memory. It then stores the value in <tt>val</tt> in the memory
6753 at <tt>ptr</tt>.</p>
6754
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6755<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6756<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
6757 the <tt>val</tt> argument and the result must be integers of the same bit
6758 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6759 integer type. The targets may only lower integer representations they
6760 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6761
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6762<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6763<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6764 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6765 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6766
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6767<h5>Examples:</h5>
6768<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]6769%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6770%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6771 store i32 4, %ptr
6772
6773%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6774%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6775 <i>; yields {i32}:result1 = 4</i>
6776%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6777%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6778
6779%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6780%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6781 <i>; yields {i32}:result2 = 8</i>
6782
6783%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6784%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6785</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6786
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6787</div>
6788
6789<!-- _______________________________________________________________________ -->
6790<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6791 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6792
6793</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6794
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6795<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6796
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6797<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6798<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
6799 any integer bit width. Not all targets support all bit widths however.</p>
6800
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6801<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6802 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6803 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6804 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6805 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]6806</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6807
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6808<h5>Overview:</h5>
6809<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
6810 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6811
6812<h5>Arguments:</h5>
6813<p>The intrinsic takes two arguments, the first a pointer to an integer value
6814 and the second an integer value. The result is also an integer value. These
6815 integer types can have any bit width, but they must all have the same bit
6816 width. The targets may only lower integer representations they support.</p>
6817
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6818<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6819<p>This intrinsic does a series of operations atomically. It first loads the
6820 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6821 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]6822
6823<h5>Examples:</h5>
6824<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]6825%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6826%ptr = bitcast i8* %mallocP to i32*
6827 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6828%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6829 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6830%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6831 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6832%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6833 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6834%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6835</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6836
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6837</div>
6838
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6839<!-- _______________________________________________________________________ -->
6840<div class="doc_subsubsection">
6841 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6842
6843</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6844
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6845<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6846
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6847<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6848<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
6849 any integer bit width and for different address spaces. Not all targets
6850 support all bit widths however.</p>
6851
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6852<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6853 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6854 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6855 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6856 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]6857</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6858
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6859<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]6860<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6861 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6862
6863<h5>Arguments:</h5>
6864<p>The intrinsic takes two arguments, the first a pointer to an integer value
6865 and the second an integer value. The result is also an integer value. These
6866 integer types can have any bit width, but they must all have the same bit
6867 width. The targets may only lower integer representations they support.</p>
6868
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6869<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6870<p>This intrinsic does a series of operations atomically. It first loads the
6871 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6872 result to <tt>ptr</tt>. It yields the original value stored
6873 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6874
6875<h5>Examples:</h5>
6876<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]6877%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6878%ptr = bitcast i8* %mallocP to i32*
6879 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6880%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6881 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6882%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6883 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6884%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6885 <i>; yields {i32}:result3 = 2</i>
6886%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6887</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6888
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6889</div>
6890
6891<!-- _______________________________________________________________________ -->
6892<div class="doc_subsubsection">
6893 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6894 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6895 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6896 <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]6897</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6898
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6899<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6900
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6901<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6902<p>These are overloaded intrinsics. You can
6903 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
6904 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
6905 bit width and for different address spaces. Not all targets support all bit
6906 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6907
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6908<pre>
6909 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6910 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6911 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6912 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]6913</pre>
6914
6915<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6916 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6917 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6918 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6919 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]6920</pre>
6921
6922<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6923 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6924 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6925 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6926 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]6927</pre>
6928
6929<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6930 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6931 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6932 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6933 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]6934</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6935
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6936<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6937<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6938 the value stored in memory at <tt>ptr</tt>. It yields the original value
6939 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6940
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6941<h5>Arguments:</h5>
6942<p>These intrinsics take two arguments, the first a pointer to an integer value
6943 and the second an integer value. The result is also an integer value. These
6944 integer types can have any bit width, but they must all have the same bit
6945 width. The targets may only lower integer representations they support.</p>
6946
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6947<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6948<p>These intrinsics does a series of operations atomically. They first load the
6949 value stored at <tt>ptr</tt>. They then do the bitwise
6950 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
6951 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6952
6953<h5>Examples:</h5>
6954<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]6955%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6956%ptr = bitcast i8* %mallocP to i32*
6957 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6958%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6959 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6960%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6961 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6962%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6963 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6964%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6965 <i>; yields {i32}:result3 = FF</i>
6966%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6967</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6968
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6969</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6970
6971<!-- _______________________________________________________________________ -->
6972<div class="doc_subsubsection">
6973 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6974 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6975 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6976 <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]6977</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6978
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6979<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6980
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6981<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6982<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6983 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
6984 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6985 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6986
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6987<pre>
6988 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6989 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6990 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6991 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]6992</pre>
6993
6994<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6995 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6996 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6997 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6998 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]6999</pre>
7000
7001<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7002 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7003 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7004 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7005 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]7006</pre>
7007
7008<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7009 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7010 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7011 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7012 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]7013</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7014
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7015<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7016<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7017 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7018 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7019
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7020<h5>Arguments:</h5>
7021<p>These intrinsics take two arguments, the first a pointer to an integer value
7022 and the second an integer value. The result is also an integer value. These
7023 integer types can have any bit width, but they must all have the same bit
7024 width. The targets may only lower integer representations they support.</p>
7025
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7026<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7027<p>These intrinsics does a series of operations atomically. They first load the
7028 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7029 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7030 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7031
7032<h5>Examples:</h5>
7033<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7034%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7035%ptr = bitcast i8* %mallocP to i32*
7036 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7037%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7038 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7039%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7040 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7041%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7042 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]7043%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7044 <i>; yields {i32}:result3 = 8</i>
7045%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7046</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7047
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7048</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7049
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7050
7051<!-- ======================================================================= -->
7052<div class="doc_subsection">
7053 <a name="int_memorymarkers">Memory Use Markers</a>
7054</div>
7055
7056<div class="doc_text">
7057
7058<p>This class of intrinsics exists to information about the lifetime of memory
7059 objects and ranges where variables are immutable.</p>
7060
7061</div>
7062
7063<!-- _______________________________________________________________________ -->
7064<div class="doc_subsubsection">
7065 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
7066</div>
7067
7068<div class="doc_text">
7069
7070<h5>Syntax:</h5>
7071<pre>
7072 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7073</pre>
7074
7075<h5>Overview:</h5>
7076<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7077 object's lifetime.</p>
7078
7079<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7080<p>The first argument is a constant integer representing the size of the
7081 object, or -1 if it is variable sized. The second argument is a pointer to
7082 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7083
7084<h5>Semantics:</h5>
7085<p>This intrinsic indicates that before this point in the code, the value of the
7086 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]7087 never be used and has an undefined value. A load from the pointer that
7088 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7089 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7090
7091</div>
7092
7093<!-- _______________________________________________________________________ -->
7094<div class="doc_subsubsection">
7095 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
7096</div>
7097
7098<div class="doc_text">
7099
7100<h5>Syntax:</h5>
7101<pre>
7102 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7103</pre>
7104
7105<h5>Overview:</h5>
7106<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7107 object's lifetime.</p>
7108
7109<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7110<p>The first argument is a constant integer representing the size of the
7111 object, or -1 if it is variable sized. The second argument is a pointer to
7112 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7113
7114<h5>Semantics:</h5>
7115<p>This intrinsic indicates that after this point in the code, the value of the
7116 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7117 never be used and has an undefined value. Any stores into the memory object
7118 following this intrinsic may be removed as dead.
7119
7120</div>
7121
7122<!-- _______________________________________________________________________ -->
7123<div class="doc_subsubsection">
7124 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
7125</div>
7126
7127<div class="doc_text">
7128
7129<h5>Syntax:</h5>
7130<pre>
7131 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;) readonly
7132</pre>
7133
7134<h5>Overview:</h5>
7135<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7136 a memory object will not change.</p>
7137
7138<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7139<p>The first argument is a constant integer representing the size of the
7140 object, or -1 if it is variable sized. The second argument is a pointer to
7141 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7142
7143<h5>Semantics:</h5>
7144<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7145 the return value, the referenced memory location is constant and
7146 unchanging.</p>
7147
7148</div>
7149
7150<!-- _______________________________________________________________________ -->
7151<div class="doc_subsubsection">
7152 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
7153</div>
7154
7155<div class="doc_text">
7156
7157<h5>Syntax:</h5>
7158<pre>
7159 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7160</pre>
7161
7162<h5>Overview:</h5>
7163<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7164 a memory object are mutable.</p>
7165
7166<h5>Arguments:</h5>
7167<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7168 The second argument is a constant integer representing the size of the
7169 object, or -1 if it is variable sized and the third argument is a pointer
7170 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7171
7172<h5>Semantics:</h5>
7173<p>This intrinsic indicates that the memory is mutable again.</p>
7174
7175</div>
7176
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7177<!-- ======================================================================= -->
7178<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7179 <a name="int_general">General Intrinsics</a>
7180</div>
7181
7182<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7183
7184<p>This class of intrinsics is designed to be generic and has no specific
7185 purpose.</p>
7186
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7187</div>
7188
7189<!-- _______________________________________________________________________ -->
7190<div class="doc_subsubsection">
7191 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
7192</div>
7193
7194<div class="doc_text">
7195
7196<h5>Syntax:</h5>
7197<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]7198 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]7199</pre>
7200
7201<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7202<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7203
7204<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7205<p>The first argument is a pointer to a value, the second is a pointer to a
7206 global string, the third is a pointer to a global string which is the source
7207 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7208
7209<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7210<p>This intrinsic allows annotation of local variables with arbitrary strings.
7211 This can be useful for special purpose optimizations that want to look for
7212 these annotations. These have no other defined use, they are ignored by code
7213 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7214
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7215</div>
7216
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7217<!-- _______________________________________________________________________ -->
7218<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]7219 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7220</div>
7221
7222<div class="doc_text">
7223
7224<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7225<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7226 any integer bit width.</p>
7227
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7228<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]7229 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7230 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7231 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7232 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7233 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]7234</pre>
7235
7236<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7237<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7238
7239<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7240<p>The first argument is an integer value (result of some expression), the
7241 second is a pointer to a global string, the third is a pointer to a global
7242 string which is the source file name, and the last argument is the line
7243 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7244
7245<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7246<p>This intrinsic allows annotations to be put on arbitrary expressions with
7247 arbitrary strings. This can be useful for special purpose optimizations that
7248 want to look for these annotations. These have no other defined use, they
7249 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7250
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7251</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7252
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7253<!-- _______________________________________________________________________ -->
7254<div class="doc_subsubsection">
7255 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
7256</div>
7257
7258<div class="doc_text">
7259
7260<h5>Syntax:</h5>
7261<pre>
7262 declare void @llvm.trap()
7263</pre>
7264
7265<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7266<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7267
7268<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7269<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7270
7271<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7272<p>This intrinsics is lowered to the target dependent trap instruction. If the
7273 target does not have a trap instruction, this intrinsic will be lowered to
7274 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7275
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7276</div>
7277
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7278<!-- _______________________________________________________________________ -->
7279<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]7280 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7281</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7282
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7283<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7284
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7285<h5>Syntax:</h5>
7286<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7287 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7288</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7289
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7290<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7291<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7292 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7293 ensure that it is placed on the stack before local variables.</p>
7294
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7295<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7296<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7297 arguments. The first argument is the value loaded from the stack
7298 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7299 that has enough space to hold the value of the guard.</p>
7300
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7301<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7302<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7303 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7304 stack. This is to ensure that if a local variable on the stack is
7305 overwritten, it will destroy the value of the guard. When the function exits,
7306 the guard on the stack is checked against the original guard. If they're
7307 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7308 function.</p>
7309
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7310</div>
7311
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7312<!-- _______________________________________________________________________ -->
7313<div class="doc_subsubsection">
7314 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
7315</div>
7316
7317<div class="doc_text">
7318
7319<h5>Syntax:</h5>
7320<pre>
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7321 declare i32 @llvm.objectsize.i32( i8* &lt;object&gt;, i1 &lt;type&gt; )
7322 declare i64 @llvm.objectsize.i64( i8* &lt;object&gt;, i1 &lt;type&gt; )
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7323</pre>
7324
7325<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7326<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information
Eric Christopherd003c5b2010-01-08 21:42:39 +0000[diff] [blame]7327 to the optimizers to discover at compile time either a) when an
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7328 operation like memcpy will either overflow a buffer that corresponds to
7329 an object, or b) to determine that a runtime check for overflow isn't
7330 necessary. An object in this context means an allocation of a
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7331 specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7332
7333<h5>Arguments:</h5>
7334<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7335 argument is a pointer to or into the <tt>object</tt>. The second argument
7336 is a boolean 0 or 1. This argument determines whether you want the
7337 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
7338 1, variables are not allowed.</p>
7339
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7340<h5>Semantics:</h5>
7341<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7342 representing the size of the object concerned or <tt>i32/i64 -1 or 0</tt>
7343 (depending on the <tt>type</tt> argument if the size cannot be determined
7344 at compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7345
7346</div>
7347
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7348<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7349<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7350<address>
7351 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]7352 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7353 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]7354 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]7355
7356 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]7357 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7358 Last modified: $Date$
7359</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]7360
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]7361</body>
7362</html>