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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 99a8205ae366d9e6bd3cdc6561a5715a5b665589 / . / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
8 <meta name="description"
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>
34 <li><a href="#linkage_linkonce">'<tt>linkonce_odr</tt>' Linkage</a></li>
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>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]46 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]47 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]48 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]49 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]50 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]51 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]52 </ol>
53 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]54 <li><a href="#typesystem">Type System</a>
55 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]56 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]57 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]58 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]59 <li><a href="#t_floating">Floating Point Types</a></li>
60 <li><a href="#t_void">Void Type</a></li>
61 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]62 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]63 </ol>
64 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]65 <li><a href="#t_derived">Derived Types</a>
66 <ol>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]67 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]68 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]69 <li><a href="#t_function">Function Type</a></li>
70 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]71 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]72 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]73 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]74 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]75 </ol>
76 </li>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]77 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]78 </ol>
79 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]80 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]81 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]82 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]83 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]84 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
85 <li><a href="#undefvalues">Undefined Values</a></li>
86 <li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]87 <li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]88 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]89 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]90 <li><a href="#othervalues">Other Values</a>
91 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]92 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]93 </ol>
94 </li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]95 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
96 <ol>
97 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]98 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
99 Global Variable</a></li>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]100 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
101 Global Variable</a></li>
102 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
103 Global Variable</a></li>
104 </ol>
105 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]106 <li><a href="#instref">Instruction Reference</a>
107 <ol>
108 <li><a href="#terminators">Terminator Instructions</a>
109 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]110 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
111 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]112 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
113 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]114 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]115 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]116 </ol>
117 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]118 <li><a href="#binaryops">Binary Operations</a>
119 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]120 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]121 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]122 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]123 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]124 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]125 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]126 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
127 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
128 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]129 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
130 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
131 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]132 </ol>
133 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]134 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
135 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]136 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
137 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
138 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]139 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]140 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]141 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]142 </ol>
143 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]144 <li><a href="#vectorops">Vector Operations</a>
145 <ol>
146 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
147 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
148 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]149 </ol>
150 </li>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]151 <li><a href="#aggregateops">Aggregate Operations</a>
152 <ol>
153 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
154 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
155 </ol>
156 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]157 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]158 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]159 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
160 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
161 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]162 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
163 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
164 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]165 </ol>
166 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]167 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]168 <ol>
169 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
170 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
171 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
172 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
173 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]174 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
175 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
176 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
177 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]178 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
179 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]180 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]181 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]182 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]183 <li><a href="#otherops">Other Operations</a>
184 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]185 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
186 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]187 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]188 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]189 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]190 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]191 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]192 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]193 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]194 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]195 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]196 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]197 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
198 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]199 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
200 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
201 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]202 </ol>
203 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]204 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
205 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]206 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
207 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
208 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]209 </ol>
210 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]211 <li><a href="#int_codegen">Code Generator Intrinsics</a>
212 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]213 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
214 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
215 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
216 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
217 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
218 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
219 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]220 </ol>
221 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]222 <li><a href="#int_libc">Standard C Library Intrinsics</a>
223 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]224 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
225 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
226 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
227 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
228 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]229 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
230 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
231 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]232 </ol>
233 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]234 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]235 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]236 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]237 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
238 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
239 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]240 </ol>
241 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]242 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
243 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]244 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
245 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
246 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
247 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
248 <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]249 <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]250 </ol>
251 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]252 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]253 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]254 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]255 <ol>
256 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]257 </ol>
258 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]259 <li><a href="#int_atomics">Atomic intrinsics</a>
260 <ol>
261 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
262 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
263 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
264 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
265 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
266 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
267 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
268 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
269 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
270 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
271 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
272 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
273 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
274 </ol>
275 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]276 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]277 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]278 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]279 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]280 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]281 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]282 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]283 '<tt>llvm.trap</tt>' Intrinsic</a></li>
284 <li><a href="#int_stackprotector">
285 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]286 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]287 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]288 </ol>
289 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]290</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]291
292<div class="doc_author">
293 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
294 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]295</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]296
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]297<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]298<div class="doc_section"> <a name="abstract">Abstract </a></div>
299<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]300
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]301<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]302
303<p>This document is a reference manual for the LLVM assembly language. LLVM is
304 a Static Single Assignment (SSA) based representation that provides type
305 safety, low-level operations, flexibility, and the capability of representing
306 'all' high-level languages cleanly. It is the common code representation
307 used throughout all phases of the LLVM compilation strategy.</p>
308
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]309</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]310
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]311<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]312<div class="doc_section"> <a name="introduction">Introduction</a> </div>
313<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]314
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]315<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]316
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]317<p>The LLVM code representation is designed to be used in three different forms:
318 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
319 for fast loading by a Just-In-Time compiler), and as a human readable
320 assembly language representation. This allows LLVM to provide a powerful
321 intermediate representation for efficient compiler transformations and
322 analysis, while providing a natural means to debug and visualize the
323 transformations. The three different forms of LLVM are all equivalent. This
324 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]325
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]326<p>The LLVM representation aims to be light-weight and low-level while being
327 expressive, typed, and extensible at the same time. It aims to be a
328 "universal IR" of sorts, by being at a low enough level that high-level ideas
329 may be cleanly mapped to it (similar to how microprocessors are "universal
330 IR's", allowing many source languages to be mapped to them). By providing
331 type information, LLVM can be used as the target of optimizations: for
332 example, through pointer analysis, it can be proven that a C automatic
333 variable is never accessed outside of the current function... allowing it to
334 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]335
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]336</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]337
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]338<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]339<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]340
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]341<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]342
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]343<p>It is important to note that this document describes 'well formed' LLVM
344 assembly language. There is a difference between what the parser accepts and
345 what is considered 'well formed'. For example, the following instruction is
346 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]347
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]348<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]349<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]350%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]351</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]352</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]353
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]354<p>...because the definition of <tt>%x</tt> does not dominate all of its
355 uses. The LLVM infrastructure provides a verification pass that may be used
356 to verify that an LLVM module is well formed. This pass is automatically run
357 by the parser after parsing input assembly and by the optimizer before it
358 outputs bitcode. The violations pointed out by the verifier pass indicate
359 bugs in transformation passes or input to the parser.</p>
360
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]361</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]362
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]363<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]364
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]365<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]366<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]367<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]368
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]369<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]370
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]371<p>LLVM identifiers come in two basic types: global and local. Global
372 identifiers (functions, global variables) begin with the <tt>'@'</tt>
373 character. Local identifiers (register names, types) begin with
374 the <tt>'%'</tt> character. Additionally, there are three different formats
375 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]376
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]377<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]378 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]379 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
380 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
381 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
382 other characters in their names can be surrounded with quotes. Special
383 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
384 ASCII code for the character in hexadecimal. In this way, any character
385 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]386
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]387 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]388 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]389
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]390 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]391 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]392</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]393
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]394<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]395 don't need to worry about name clashes with reserved words, and the set of
396 reserved words may be expanded in the future without penalty. Additionally,
397 unnamed identifiers allow a compiler to quickly come up with a temporary
398 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]399
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]400<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]401 languages. There are keywords for different opcodes
402 ('<tt><a href="#i_add">add</a></tt>',
403 '<tt><a href="#i_bitcast">bitcast</a></tt>',
404 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
405 ('<tt><a href="#t_void">void</a></tt>',
406 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
407 reserved words cannot conflict with variable names, because none of them
408 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]409
410<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]411 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]412
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]413<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]414
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]415<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]416<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]417%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]418</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]419</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]420
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]421<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]422
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]423<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]424<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]425%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]426</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]427</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]428
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]429<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]430
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]431<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]432<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]433<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
434<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
435%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]436</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]437</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]438
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]439<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
440 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]441
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]442<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]443 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]444 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]445
446 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]447 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]448
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]449 <li>Unnamed temporaries are numbered sequentially</li>
450</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]451
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]452<p>...and it also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]453 demonstrating instructions, we will follow an instruction with a comment that
454 defines the type and name of value produced. Comments are shown in italic
455 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]456
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]457</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]458
459<!-- *********************************************************************** -->
460<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
461<!-- *********************************************************************** -->
462
463<!-- ======================================================================= -->
464<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
465</div>
466
467<div class="doc_text">
468
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]469<p>LLVM programs are composed of "Module"s, each of which is a translation unit
470 of the input programs. Each module consists of functions, global variables,
471 and symbol table entries. Modules may be combined together with the LLVM
472 linker, which merges function (and global variable) definitions, resolves
473 forward declarations, and merges symbol table entries. Here is an example of
474 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]475
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]476<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]477<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]478<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
479 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]480
481<i>; External declaration of the puts function</i>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]482<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]483
484<i>; Definition of main function</i>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]485define i32 @main() { <i>; i32()* </i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]486 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]487 %cast210 = <a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]488 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]489
490 <i>; Call puts function to write out the string to stdout...</i>
491 <a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]492 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]493 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]494 href="#i_ret">ret</a> i32 0<br>}<br>
495</pre>
496</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]497
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]498<p>This example is made up of a <a href="#globalvars">global variable</a> named
499 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function, and
500 a <a href="#functionstructure">function definition</a> for
501 "<tt>main</tt>".</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]502
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]503<p>In general, a module is made up of a list of global values, where both
504 functions and global variables are global values. Global values are
505 represented by a pointer to a memory location (in this case, a pointer to an
506 array of char, and a pointer to a function), and have one of the
507 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]508
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]509</div>
510
511<!-- ======================================================================= -->
512<div class="doc_subsection">
513 <a name="linkage">Linkage Types</a>
514</div>
515
516<div class="doc_text">
517
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]518<p>All Global Variables and Functions have one of the following types of
519 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]520
521<dl>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]522 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]523 <dd>Global values with private linkage are only directly accessible by objects
524 in the current module. In particular, linking code into a module with an
525 private global value may cause the private to be renamed as necessary to
526 avoid collisions. Because the symbol is private to the module, all
527 references can be updated. This doesn't show up in any symbol table in the
528 object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]529
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]530 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt>: </dt>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]531 <dd>Similar to private, but the symbol is passed through the assembler and
532 removed by the linker after evaluation.</dd>
533
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]534 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]535 <dd>Similar to private, but the value shows as a local symbol
536 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
537 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]538
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]539 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt>: </dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]540 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]541 into the object file corresponding to the LLVM module. They exist to
542 allow inlining and other optimizations to take place given knowledge of
543 the definition of the global, which is known to be somewhere outside the
544 module. Globals with <tt>available_externally</tt> linkage are allowed to
545 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
546 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]547
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]548 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]549 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]550 the same name when linkage occurs. This is typically used to implement
551 inline functions, templates, or other code which must be generated in each
552 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
553 allowed to be discarded.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]554
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]555 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]556 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
557 linkage, except that unreferenced <tt>common</tt> globals may not be
558 discarded. This is used for globals that may be emitted in multiple
559 translation units, but that are not guaranteed to be emitted into every
560 translation unit that uses them. One example of this is tentative
561 definitions in C, such as "<tt>int X;</tt>" at global scope.</dd>
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]562
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]563 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Dale Johannesen2307a7f2008-05-23 23:13:41 +0000[diff] [blame]564 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]565 that some targets may choose to emit different assembly sequences for them
566 for target-dependent reasons. This is used for globals that are declared
567 "weak" in C source code.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]568
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]569 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]570 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]571 pointer to array type. When two global variables with appending linkage
572 are linked together, the two global arrays are appended together. This is
573 the LLVM, typesafe, equivalent of having the system linker append together
574 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]575
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]576 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]577 <dd>The semantics of this linkage follow the ELF object file model: the symbol
578 is weak until linked, if not linked, the symbol becomes null instead of
579 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]580
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]581 <dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]582 <dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]583 <dd>Some languages allow differing globals to be merged, such as two functions
584 with different semantics. Other languages, such as <tt>C++</tt>, ensure
585 that only equivalent globals are ever merged (the "one definition rule" -
586 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
587 and <tt>weak_odr</tt> linkage types to indicate that the global will only
588 be merged with equivalent globals. These linkage types are otherwise the
589 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]590
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]591 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]592 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]593 visible, meaning that it participates in linkage and can be used to
594 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]595</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]596
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]597<p>The next two types of linkage are targeted for Microsoft Windows platform
598 only. They are designed to support importing (exporting) symbols from (to)
599 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]600
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]601<dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]602 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]603 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]604 or variable via a global pointer to a pointer that is set up by the DLL
605 exporting the symbol. On Microsoft Windows targets, the pointer name is
606 formed by combining <code>__imp_</code> and the function or variable
607 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]608
609 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]610 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]611 pointer to a pointer in a DLL, so that it can be referenced with the
612 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
613 name is formed by combining <code>__imp_</code> and the function or
614 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]615</dl>
616
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]617<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
618 another module defined a "<tt>.LC0</tt>" variable and was linked with this
619 one, one of the two would be renamed, preventing a collision. Since
620 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
621 declarations), they are accessible outside of the current module.</p>
622
623<p>It is illegal for a function <i>declaration</i> to have any linkage type
624 other than "externally visible", <tt>dllimport</tt>
625 or <tt>extern_weak</tt>.</p>
626
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]627<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]628 or <tt>weak_odr</tt> linkages.</p>
629
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]630</div>
631
632<!-- ======================================================================= -->
633<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]634 <a name="callingconv">Calling Conventions</a>
635</div>
636
637<div class="doc_text">
638
639<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]640 and <a href="#i_invoke">invokes</a> can all have an optional calling
641 convention specified for the call. The calling convention of any pair of
642 dynamic caller/callee must match, or the behavior of the program is
643 undefined. The following calling conventions are supported by LLVM, and more
644 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]645
646<dl>
647 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]648 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]649 specified) matches the target C calling conventions. This calling
650 convention supports varargs function calls and tolerates some mismatch in
651 the declared prototype and implemented declaration of the function (as
652 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]653
654 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]655 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]656 (e.g. by passing things in registers). This calling convention allows the
657 target to use whatever tricks it wants to produce fast code for the
658 target, without having to conform to an externally specified ABI
659 (Application Binary Interface). Implementations of this convention should
660 allow arbitrary <a href="CodeGenerator.html#tailcallopt">tail call
661 optimization</a> to be supported. This calling convention does not
662 support varargs and requires the prototype of all callees to exactly match
663 the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]664
665 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]666 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]667 as possible under the assumption that the call is not commonly executed.
668 As such, these calls often preserve all registers so that the call does
669 not break any live ranges in the caller side. This calling convention
670 does not support varargs and requires the prototype of all callees to
671 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]672
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]673 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]674 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]675 target-specific calling conventions to be used. Target specific calling
676 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]677</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]678
679<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]680 support Pascal conventions or any other well-known target-independent
681 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]682
683</div>
684
685<!-- ======================================================================= -->
686<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]687 <a name="visibility">Visibility Styles</a>
688</div>
689
690<div class="doc_text">
691
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]692<p>All Global Variables and Functions have one of the following visibility
693 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]694
695<dl>
696 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]697 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]698 that the declaration is visible to other modules and, in shared libraries,
699 means that the declared entity may be overridden. On Darwin, default
700 visibility means that the declaration is visible to other modules. Default
701 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]702
703 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]704 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]705 object if they are in the same shared object. Usually, hidden visibility
706 indicates that the symbol will not be placed into the dynamic symbol
707 table, so no other module (executable or shared library) can reference it
708 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]709
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]710 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]711 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]712 the dynamic symbol table, but that references within the defining module
713 will bind to the local symbol. That is, the symbol cannot be overridden by
714 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]715</dl>
716
717</div>
718
719<!-- ======================================================================= -->
720<div class="doc_subsection">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]721 <a name="namedtypes">Named Types</a>
722</div>
723
724<div class="doc_text">
725
726<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]727 it easier to read the IR and make the IR more condensed (particularly when
728 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]729
730<div class="doc_code">
731<pre>
732%mytype = type { %mytype*, i32 }
733</pre>
734</div>
735
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]736<p>You may give a name to any <a href="#typesystem">type</a> except
737 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
738 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]739
740<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]741 and that you can therefore specify multiple names for the same type. This
742 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
743 uses structural typing, the name is not part of the type. When printing out
744 LLVM IR, the printer will pick <em>one name</em> to render all types of a
745 particular shape. This means that if you have code where two different
746 source types end up having the same LLVM type, that the dumper will sometimes
747 print the "wrong" or unexpected type. This is an important design point and
748 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]749
750</div>
751
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]752<!-- ======================================================================= -->
753<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]754 <a name="globalvars">Global Variables</a>
755</div>
756
757<div class="doc_text">
758
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]759<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]760 instead of run-time. Global variables may optionally be initialized, may
761 have an explicit section to be placed in, and may have an optional explicit
762 alignment specified. A variable may be defined as "thread_local", which
763 means that it will not be shared by threads (each thread will have a
764 separated copy of the variable). A variable may be defined as a global
765 "constant," which indicates that the contents of the variable
766 will <b>never</b> be modified (enabling better optimization, allowing the
767 global data to be placed in the read-only section of an executable, etc).
768 Note that variables that need runtime initialization cannot be marked
769 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]770
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]771<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
772 constant, even if the final definition of the global is not. This capability
773 can be used to enable slightly better optimization of the program, but
774 requires the language definition to guarantee that optimizations based on the
775 'constantness' are valid for the translation units that do not include the
776 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]777
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]778<p>As SSA values, global variables define pointer values that are in scope
779 (i.e. they dominate) all basic blocks in the program. Global variables
780 always define a pointer to their "content" type because they describe a
781 region of memory, and all memory objects in LLVM are accessed through
782 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]783
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]784<p>A global variable may be declared to reside in a target-specific numbered
785 address space. For targets that support them, address spaces may affect how
786 optimizations are performed and/or what target instructions are used to
787 access the variable. The default address space is zero. The address space
788 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]789
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]790<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]791 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]792
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]793<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]794 the alignment is set to zero, the alignment of the global is set by the
795 target to whatever it feels convenient. If an explicit alignment is
796 specified, the global is forced to have at least that much alignment. All
797 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]798
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]799<p>For example, the following defines a global in a numbered address space with
800 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]801
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]802<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]803<pre>
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]804@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]805</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]806</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]807
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]808</div>
809
810
811<!-- ======================================================================= -->
812<div class="doc_subsection">
813 <a name="functionstructure">Functions</a>
814</div>
815
816<div class="doc_text">
817
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]818<p>LLVM function definitions consist of the "<tt>define</tt>" keyord, an
819 optional <a href="#linkage">linkage type</a>, an optional
820 <a href="#visibility">visibility style</a>, an optional
821 <a href="#callingconv">calling convention</a>, a return type, an optional
822 <a href="#paramattrs">parameter attribute</a> for the return type, a function
823 name, a (possibly empty) argument list (each with optional
824 <a href="#paramattrs">parameter attributes</a>), optional
825 <a href="#fnattrs">function attributes</a>, an optional section, an optional
826 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
827 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]828
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]829<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
830 optional <a href="#linkage">linkage type</a>, an optional
831 <a href="#visibility">visibility style</a>, an optional
832 <a href="#callingconv">calling convention</a>, a return type, an optional
833 <a href="#paramattrs">parameter attribute</a> for the return type, a function
834 name, a possibly empty list of arguments, an optional alignment, and an
835 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]836
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]837<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]838 (Control Flow Graph) for the function. Each basic block may optionally start
839 with a label (giving the basic block a symbol table entry), contains a list
840 of instructions, and ends with a <a href="#terminators">terminator</a>
841 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]842
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]843<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]844 executed on entrance to the function, and it is not allowed to have
845 predecessor basic blocks (i.e. there can not be any branches to the entry
846 block of a function). Because the block can have no predecessors, it also
847 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]848
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]849<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]850 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]851
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]852<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]853 the alignment is set to zero, the alignment of the function is set by the
854 target to whatever it feels convenient. If an explicit alignment is
855 specified, the function is forced to have at least that much alignment. All
856 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]857
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]858<h5>Syntax:</h5>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]859<div class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]860<pre>
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]861define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]862 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
863 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
864 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
865 [<a href="#gc">gc</a>] { ... }
866</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]867</div>
868
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]869</div>
870
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]871<!-- ======================================================================= -->
872<div class="doc_subsection">
873 <a name="aliasstructure">Aliases</a>
874</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]875
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]876<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]877
878<p>Aliases act as "second name" for the aliasee value (which can be either
879 function, global variable, another alias or bitcast of global value). Aliases
880 may have an optional <a href="#linkage">linkage type</a>, and an
881 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]882
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]883<h5>Syntax:</h5>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]884<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]885<pre>
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]886@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]887</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]888</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]889
890</div>
891
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]892<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]893<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]894
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]895<div class="doc_text">
896
897<p>The return type and each parameter of a function type may have a set of
898 <i>parameter attributes</i> associated with them. Parameter attributes are
899 used to communicate additional information about the result or parameters of
900 a function. Parameter attributes are considered to be part of the function,
901 not of the function type, so functions with different parameter attributes
902 can have the same function type.</p>
903
904<p>Parameter attributes are simple keywords that follow the type specified. If
905 multiple parameter attributes are needed, they are space separated. For
906 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]907
908<div class="doc_code">
909<pre>
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]910declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]911declare i32 @atoi(i8 zeroext)
912declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]913</pre>
914</div>
915
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]916<p>Note that any attributes for the function result (<tt>nounwind</tt>,
917 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]918
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]919<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]920
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]921<dl>
922 <dt><tt>zeroext</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]923 <dd>This indicates to the code generator that the parameter or return value
924 should be zero-extended to a 32-bit value by the caller (for a parameter)
925 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]926
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]927 <dt><tt>signext</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]928 <dd>This indicates to the code generator that the parameter or return value
929 should be sign-extended to a 32-bit value by the caller (for a parameter)
930 or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]931
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]932 <dt><tt>inreg</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]933 <dd>This indicates that this parameter or return value should be treated in a
934 special target-dependent fashion during while emitting code for a function
935 call or return (usually, by putting it in a register as opposed to memory,
936 though some targets use it to distinguish between two different kinds of
937 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]938
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]939 <dt><tt><a name="byval">byval</a></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]940 <dd>This indicates that the pointer parameter should really be passed by value
941 to the function. The attribute implies that a hidden copy of the pointee
942 is made between the caller and the callee, so the callee is unable to
943 modify the value in the callee. This attribute is only valid on LLVM
944 pointer arguments. It is generally used to pass structs and arrays by
945 value, but is also valid on pointers to scalars. The copy is considered
946 to belong to the caller not the callee (for example,
947 <tt><a href="#readonly">readonly</a></tt> functions should not write to
948 <tt>byval</tt> parameters). This is not a valid attribute for return
949 values. The byval attribute also supports specifying an alignment with
950 the align attribute. This has a target-specific effect on the code
951 generator that usually indicates a desired alignment for the synthesized
952 stack slot.</dd>
953
954 <dt><tt>sret</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]955 <dd>This indicates that the pointer parameter specifies the address of a
956 structure that is the return value of the function in the source program.
957 This pointer must be guaranteed by the caller to be valid: loads and
958 stores to the structure may be assumed by the callee to not to trap. This
959 may only be applied to the first parameter. This is not a valid attribute
960 for return values. </dd>
961
962 <dt><tt>noalias</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]963 <dd>This indicates that the pointer does not alias any global or any other
964 parameter. The caller is responsible for ensuring that this is the
965 case. On a function return value, <tt>noalias</tt> additionally indicates
966 that the pointer does not alias any other pointers visible to the
967 caller. For further details, please see the discussion of the NoAlias
968 response in
969 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
970 analysis</a>.</dd>
971
972 <dt><tt>nocapture</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]973 <dd>This indicates that the callee does not make any copies of the pointer
974 that outlive the callee itself. This is not a valid attribute for return
975 values.</dd>
976
977 <dt><tt>nest</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]978 <dd>This indicates that the pointer parameter can be excised using the
979 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
980 attribute for return values.</dd>
981</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]982
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]983</div>
984
985<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]986<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]987 <a name="gc">Garbage Collector Names</a>
988</div>
989
990<div class="doc_text">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]991
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]992<p>Each function may specify a garbage collector name, which is simply a
993 string:</p>
994
995<div class="doc_code">
996<pre>
997define void @f() gc "name" { ...
998</pre>
999</div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1000
1001<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1002 collector which will cause the compiler to alter its output in order to
1003 support the named garbage collection algorithm.</p>
1004
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1005</div>
1006
1007<!-- ======================================================================= -->
1008<div class="doc_subsection">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1009 <a name="fnattrs">Function Attributes</a>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1010</div>
1011
1012<div class="doc_text">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1013
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1014<p>Function attributes are set to communicate additional information about a
1015 function. Function attributes are considered to be part of the function, not
1016 of the function type, so functions with different parameter attributes can
1017 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1018
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1019<p>Function attributes are simple keywords that follow the type specified. If
1020 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1021
1022<div class="doc_code">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1023<pre>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1024define void @f() noinline { ... }
1025define void @f() alwaysinline { ... }
1026define void @f() alwaysinline optsize { ... }
1027define void @f() optsize
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1028</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1029</div>
1030
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1031<dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1032 <dt><tt>alwaysinline</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1033 <dd>This attribute indicates that the inliner should attempt to inline this
1034 function into callers whenever possible, ignoring any active inlining size
1035 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1036
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1037 <dt><tt>noinline</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1038 <dd>This attribute indicates that the inliner should never inline this
1039 function in any situation. This attribute may not be used together with
1040 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1041
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1042 <dt><tt>optsize</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1043 <dd>This attribute suggests that optimization passes and code generator passes
1044 make choices that keep the code size of this function low, and otherwise
1045 do optimizations specifically to reduce code size.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1046
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1047 <dt><tt>noreturn</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1048 <dd>This function attribute indicates that the function never returns
1049 normally. This produces undefined behavior at runtime if the function
1050 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1051
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1052 <dt><tt>nounwind</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1053 <dd>This function attribute indicates that the function never returns with an
1054 unwind or exceptional control flow. If the function does unwind, its
1055 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1056
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1057 <dt><tt>readnone</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1058 <dd>This attribute indicates that the function computes its result (or decides
1059 to unwind an exception) based strictly on its arguments, without
1060 dereferencing any pointer arguments or otherwise accessing any mutable
1061 state (e.g. memory, control registers, etc) visible to caller functions.
1062 It does not write through any pointer arguments
1063 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1064 changes any state visible to callers. This means that it cannot unwind
1065 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1066 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1067
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1068 <dt><tt><a name="readonly">readonly</a></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1069 <dd>This attribute indicates that the function does not write through any
1070 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1071 arguments) or otherwise modify any state (e.g. memory, control registers,
1072 etc) visible to caller functions. It may dereference pointer arguments
1073 and read state that may be set in the caller. A readonly function always
1074 returns the same value (or unwinds an exception identically) when called
1075 with the same set of arguments and global state. It cannot unwind an
1076 exception by calling the <tt>C++</tt> exception throwing methods, but may
1077 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1078
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1079 <dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1080 <dd>This attribute indicates that the function should emit a stack smashing
1081 protector. It is in the form of a "canary"&mdash;a random value placed on
1082 the stack before the local variables that's checked upon return from the
1083 function to see if it has been overwritten. A heuristic is used to
1084 determine if a function needs stack protectors or not.<br>
1085<br>
1086 If a function that has an <tt>ssp</tt> attribute is inlined into a
1087 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1088 function will have an <tt>ssp</tt> attribute.</dd>
1089
1090 <dt><tt>sspreq</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1091 <dd>This attribute indicates that the function should <em>always</em> emit a
1092 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1093 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1094<br>
1095 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1096 function that doesn't have an <tt>sspreq</tt> attribute or which has
1097 an <tt>ssp</tt> attribute, then the resulting function will have
1098 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1099
1100 <dt><tt>noredzone</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1101 <dd>This attribute indicates that the code generator should not use a red
1102 zone, even if the target-specific ABI normally permits it.</dd>
1103
1104 <dt><tt>noimplicitfloat</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1105 <dd>This attributes disables implicit floating point instructions.</dd>
1106
1107 <dt><tt>naked</tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1108 <dd>This attribute disables prologue / epilogue emission for the function.
1109 This can have very system-specific consequences.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1110</dl>
1111
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1112</div>
1113
1114<!-- ======================================================================= -->
1115<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1116 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1117</div>
1118
1119<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1120
1121<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1122 the GCC "file scope inline asm" blocks. These blocks are internally
1123 concatenated by LLVM and treated as a single unit, but may be separated in
1124 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1125
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1126<div class="doc_code">
1127<pre>
1128module asm "inline asm code goes here"
1129module asm "more can go here"
1130</pre>
1131</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1132
1133<p>The strings can contain any character by escaping non-printable characters.
1134 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]1135 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1136
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1137<p>The inline asm code is simply printed to the machine code .s file when
1138 assembly code is generated.</p>
1139
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1140</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1141
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1142<!-- ======================================================================= -->
1143<div class="doc_subsection">
1144 <a name="datalayout">Data Layout</a>
1145</div>
1146
1147<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1148
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1149<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1150 data is to be laid out in memory. The syntax for the data layout is
1151 simply:</p>
1152
1153<div class="doc_code">
1154<pre>
1155target datalayout = "<i>layout specification</i>"
1156</pre>
1157</div>
1158
1159<p>The <i>layout specification</i> consists of a list of specifications
1160 separated by the minus sign character ('-'). Each specification starts with
1161 a letter and may include other information after the letter to define some
1162 aspect of the data layout. The specifications accepted are as follows:</p>
1163
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1164<dl>
1165 <dt><tt>E</tt></dt>
1166 <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]1167 bits with the most significance have the lowest address location.</dd>
1168
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1169 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1170 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1171 the bits with the least significance have the lowest address
1172 location.</dd>
1173
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1174 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1175 <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]1176 <i>preferred</i> alignments. All sizes are in bits. Specifying
1177 the <i>pref</i> alignment is optional. If omitted, the
1178 preceding <tt>:</tt> should be omitted too.</dd>
1179
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1180 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1181 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1182 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1183
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1184 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1185 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1186 <i>size</i>.</dd>
1187
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1188 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1189 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1190 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1191 (double).</dd>
1192
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1193 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1194 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1195 <i>size</i>.</dd>
1196
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1197 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1198 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1199 <i>size</i>.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1200</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1201
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1202<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1203 default set of specifications which are then (possibly) overriden by the
1204 specifications in the <tt>datalayout</tt> keyword. The default specifications
1205 are given in this list:</p>
1206
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1207<ul>
1208 <li><tt>E</tt> - big endian</li>
1209 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1210 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1211 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1212 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1213 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1214 <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]1215 alignment of 64-bits</li>
1216 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1217 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1218 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1219 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1220 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1221 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1222</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1223
1224<p>When LLVM is determining the alignment for a given type, it uses the
1225 following rules:</p>
1226
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1227<ol>
1228 <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]1229 specification is used.</li>
1230
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1231 <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]1232 smallest integer type that is larger than the bitwidth of the sought type
1233 is used. If none of the specifications are larger than the bitwidth then
1234 the the largest integer type is used. For example, given the default
1235 specifications above, the i7 type will use the alignment of i8 (next
1236 largest) while both i65 and i256 will use the alignment of i64 (largest
1237 specified).</li>
1238
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1239 <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]1240 largest vector type that is smaller than the sought vector type will be
1241 used as a fall back. This happens because &lt;128 x double&gt; can be
1242 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1243</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1244
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1245</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1246
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1247<!-- ======================================================================= -->
1248<div class="doc_subsection">
1249 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1250</div>
1251
1252<div class="doc_text">
1253
1254<p>Any memory access must be done though a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame^]1255with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1256is undefined. Pointer values are associated with address ranges
1257according to the following rules:</p>
1258
1259<ul>
1260 <li>A pointer value formed from a <tt>getelementptr</tt> instruction is
1261 associated with the addresses associated with the first operand of
1262 the <tt>getelementptr</tt>.</li>
1263 <li>An addresses of a global variable is associated with the address
1264 range of the variable's storage.</li>
1265 <li>The result value of an allocation instruction is associated with
1266 the address range of the allocated storage.</li>
1267 <li>A null pointer in the default address-space is associated with
1268 no addresses.</li>
1269 <li>A pointer value formed by an <tt>inttoptr</tt> is associated with
1270 all address ranges of all pointer values that contribute (directly
1271 or indirectly) to the computation of the pointer's value.</li>
1272 <li>The result value of a <tt>bitcast</tt> is associated with all
1273 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1274 <li>An integer constant other than zero or a pointer value returned
1275 from a function not defined within LLVM may be associated with address
1276 ranges allocated through mechanisms other than those provided by
1277 LLVM. Such ranges shall not overlap with any ranges of address
1278 allocated by mechanisms provided by LLVM.</li>
1279 </ul>
1280
1281<p>LLVM IR does not associate types with memory. The result type of a
1282<tt>load</tt> merely indicates the size and alignment of the memory from
1283which to load, as well as the interpretation of the value. The first
1284operand of a <tt>store</tt> similarly only indicates the size and
1285alignment of the store.</p>
1286
1287<p>Consequently, type-based alias analysis, aka TBAA, aka
1288<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1289LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1290additional information which specialized optimization passes may use
1291to implement type-based alias analysis.</p>
1292
1293</div>
1294
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1295<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1296<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1297<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1298
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1299<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1300
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1301<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1302 intermediate representation. Being typed enables a number of optimizations
1303 to be performed on the intermediate representation directly, without having
1304 to do extra analyses on the side before the transformation. A strong type
1305 system makes it easier to read the generated code and enables novel analyses
1306 and transformations that are not feasible to perform on normal three address
1307 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1308
1309</div>
1310
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1311<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1312<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1313Classifications</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1314
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1315<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1316
1317<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1318
1319<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1320 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1321 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1322 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1323 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1324 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1325 </tr>
1326 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1327 <td><a href="#t_floating">floating point</a></td>
1328 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1329 </tr>
1330 <tr>
1331 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1332 <td><a href="#t_integer">integer</a>,
1333 <a href="#t_floating">floating point</a>,
1334 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1335 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1336 <a href="#t_struct">structure</a>,
1337 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1338 <a href="#t_label">label</a>,
1339 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1340 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1341 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1342 <tr>
1343 <td><a href="#t_primitive">primitive</a></td>
1344 <td><a href="#t_label">label</a>,
1345 <a href="#t_void">void</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1346 <a href="#t_floating">floating point</a>,
1347 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1348 </tr>
1349 <tr>
1350 <td><a href="#t_derived">derived</a></td>
1351 <td><a href="#t_integer">integer</a>,
1352 <a href="#t_array">array</a>,
1353 <a href="#t_function">function</a>,
1354 <a href="#t_pointer">pointer</a>,
1355 <a href="#t_struct">structure</a>,
1356 <a href="#t_pstruct">packed structure</a>,
1357 <a href="#t_vector">vector</a>,
1358 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1359 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1360 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1361 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1362</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1363
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1364<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1365 important. Values of these types are the only ones which can be produced by
1366 instructions, passed as arguments, or used as operands to instructions.</p>
1367
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1368</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1369
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1370<!-- ======================================================================= -->
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1371<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1372
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1373<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1374
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1375<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1376 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1377
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1378</div>
1379
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1380<!-- _______________________________________________________________________ -->
1381<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1382
1383<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1384
1385<table>
1386 <tbody>
1387 <tr><th>Type</th><th>Description</th></tr>
1388 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1389 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1390 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1391 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1392 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1393 </tbody>
1394</table>
1395
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1396</div>
1397
1398<!-- _______________________________________________________________________ -->
1399<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1400
1401<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1402
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1403<h5>Overview:</h5>
1404<p>The void type does not represent any value and has no size.</p>
1405
1406<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1407<pre>
1408 void
1409</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1410
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1411</div>
1412
1413<!-- _______________________________________________________________________ -->
1414<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1415
1416<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1417
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1418<h5>Overview:</h5>
1419<p>The label type represents code labels.</p>
1420
1421<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1422<pre>
1423 label
1424</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1425
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1426</div>
1427
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1428<!-- _______________________________________________________________________ -->
1429<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1430
1431<div class="doc_text">
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1432
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1433<h5>Overview:</h5>
1434<p>The metadata type represents embedded metadata. The only derived type that
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1435 may contain metadata is <tt>metadata*</tt> or a function type that returns or
1436 takes metadata typed parameters, but not pointer to metadata types.</p>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1437
1438<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1439<pre>
1440 metadata
1441</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1442
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1443</div>
1444
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1445
1446<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1447<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1448
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1449<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1450
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1451<p>The real power in LLVM comes from the derived types in the system. This is
1452 what allows a programmer to represent arrays, functions, pointers, and other
1453 useful types. Note that these derived types may be recursive: For example,
1454 it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1455
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1456</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1457
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1458<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1459<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1460
1461<div class="doc_text">
1462
1463<h5>Overview:</h5>
1464<p>The integer type is a very simple derived type that simply specifies an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1465 arbitrary bit width for the integer type desired. Any bit width from 1 bit to
1466 2^23-1 (about 8 million) can be specified.</p>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1467
1468<h5>Syntax:</h5>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1469<pre>
1470 iN
1471</pre>
1472
1473<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1474 value.</p>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1475
1476<h5>Examples:</h5>
1477<table class="layout">
Nick Lewycky86c48642009-05-24 02:46:06 +0000[diff] [blame]1478 <tr class="layout">
1479 <td class="left"><tt>i1</tt></td>
1480 <td class="left">a single-bit integer.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1481 </tr>
Nick Lewycky86c48642009-05-24 02:46:06 +0000[diff] [blame]1482 <tr class="layout">
1483 <td class="left"><tt>i32</tt></td>
1484 <td class="left">a 32-bit integer.</td>
1485 </tr>
1486 <tr class="layout">
1487 <td class="left"><tt>i1942652</tt></td>
1488 <td class="left">a really big integer of over 1 million bits.</td>
1489 </tr>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1490</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1491
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1492<p>Note that the code generator does not yet support large integer types to be
1493 used as function return types. The specific limit on how large a return type
1494 the code generator can currently handle is target-dependent; currently it's
1495 often 64 bits for 32-bit targets and 128 bits for 64-bit targets.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1496
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1497</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1498
1499<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1500<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1501
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1502<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1503
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1504<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1505<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1506 sequentially in memory. The array type requires a size (number of elements)
1507 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1508
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1509<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1510<pre>
1511 [&lt;# elements&gt; x &lt;elementtype&gt;]
1512</pre>
1513
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1514<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1515 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1516
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1517<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1518<table class="layout">
1519 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1520 <td class="left"><tt>[40 x i32]</tt></td>
1521 <td class="left">Array of 40 32-bit integer values.</td>
1522 </tr>
1523 <tr class="layout">
1524 <td class="left"><tt>[41 x i32]</tt></td>
1525 <td class="left">Array of 41 32-bit integer values.</td>
1526 </tr>
1527 <tr class="layout">
1528 <td class="left"><tt>[4 x i8]</tt></td>
1529 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1530 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1531</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1532<p>Here are some examples of multidimensional arrays:</p>
1533<table class="layout">
1534 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1535 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1536 <td class="left">3x4 array of 32-bit integer values.</td>
1537 </tr>
1538 <tr class="layout">
1539 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1540 <td class="left">12x10 array of single precision floating point values.</td>
1541 </tr>
1542 <tr class="layout">
1543 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1544 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1545 </tr>
1546</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1547
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1548<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1549 length array. Normally, accesses past the end of an array are undefined in
1550 LLVM (e.g. it is illegal to access the 5th element of a 3 element array). As
1551 a special case, however, zero length arrays are recognized to be variable
1552 length. This allows implementation of 'pascal style arrays' with the LLVM
1553 type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1554
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1555<p>Note that the code generator does not yet support large aggregate types to be
1556 used as function return types. The specific limit on how large an aggregate
1557 return type the code generator can currently handle is target-dependent, and
1558 also dependent on the aggregate element types.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1559
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1560</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1561
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1562<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1563<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1564
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1565<div class="doc_text">
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1566
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1567<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1568<p>The function type can be thought of as a function signature. It consists of
1569 a return type and a list of formal parameter types. The return type of a
1570 function type is a scalar type, a void type, or a struct type. If the return
1571 type is a struct type then all struct elements must be of first class types,
1572 and the struct must have at least one element.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1573
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1574<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1575<pre>
1576 &lt;returntype list&gt; (&lt;parameter list&gt;)
1577</pre>
1578
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1579<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]1580 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1581 which indicates that the function takes a variable number of arguments.
1582 Variable argument functions can access their arguments with
1583 the <a href="#int_varargs">variable argument handling intrinsic</a>
1584 functions. '<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1585 <a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1586
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1587<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1588<table class="layout">
1589 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1590 <td class="left"><tt>i32 (i32)</tt></td>
1591 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1592 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1593 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1594 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1595 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1596 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1597 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1598 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1599 <tt>float</tt>.
1600 </td>
1601 </tr><tr class="layout">
1602 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1603 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1604 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1605 which returns an integer. This is the signature for <tt>printf</tt> in
1606 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1607 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1608 </tr><tr class="layout">
1609 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanb0a57aa2008-11-27 06:41:20 +0000[diff] [blame]1610 <td class="left">A function taking an <tt>i32</tt>, returning two
1611 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1612 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1613 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1614</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1615
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1616</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1617
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1618<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1619<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1620
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1621<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1622
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1623<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1624<p>The structure type is used to represent a collection of data members together
1625 in memory. The packing of the field types is defined to match the ABI of the
1626 underlying processor. The elements of a structure may be any type that has a
1627 size.</p>
1628
1629<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1630 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1631 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1632
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1633<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1634<pre>
1635 { &lt;type list&gt; }
1636</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1637
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1638<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1639<table class="layout">
1640 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1641 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1642 <td class="left">A triple of three <tt>i32</tt> values</td>
1643 </tr><tr class="layout">
1644 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1645 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1646 second element is a <a href="#t_pointer">pointer</a> to a
1647 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1648 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1649 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1650</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1651
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1652<p>Note that the code generator does not yet support large aggregate types to be
1653 used as function return types. The specific limit on how large an aggregate
1654 return type the code generator can currently handle is target-dependent, and
1655 also dependent on the aggregate element types.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1656
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1657</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1658
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1659<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1660<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1661</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1662
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1663<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1664
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1665<h5>Overview:</h5>
1666<p>The packed structure type is used to represent a collection of data members
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1667 together in memory. There is no padding between fields. Further, the
1668 alignment of a packed structure is 1 byte. The elements of a packed
1669 structure may be any type that has a size.</p>
1670
1671<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1672 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1673 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1674
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1675<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1676<pre>
1677 &lt; { &lt;type list&gt; } &gt;
1678</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1679
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1680<h5>Examples:</h5>
1681<table class="layout">
1682 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1683 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1684 <td class="left">A triple of three <tt>i32</tt> values</td>
1685 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1686 <td class="left">
1687<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1688 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1689 second element is a <a href="#t_pointer">pointer</a> to a
1690 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1691 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1692 </tr>
1693</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1694
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1695</div>
1696
1697<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1698<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1699
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1700<div class="doc_text">
1701
1702<h5>Overview:</h5>
1703<p>As in many languages, the pointer type represents a pointer or reference to
1704 another object, which must live in memory. Pointer types may have an optional
1705 address space attribute defining the target-specific numbered address space
1706 where the pointed-to object resides. The default address space is zero.</p>
1707
1708<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1709 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1710
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1711<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1712<pre>
1713 &lt;type&gt; *
1714</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1715
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1716<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1717<table class="layout">
1718 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1719 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1720 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1721 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1722 </tr>
1723 <tr class="layout">
1724 <td class="left"><tt>i32 (i32 *) *</tt></td>
1725 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1726 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1727 <tt>i32</tt>.</td>
1728 </tr>
1729 <tr class="layout">
1730 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1731 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1732 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1733 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1734</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1735
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1736</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1737
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1738<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1739<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1740
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1741<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1742
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1743<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1744<p>A vector type is a simple derived type that represents a vector of elements.
1745 Vector types are used when multiple primitive data are operated in parallel
1746 using a single instruction (SIMD). A vector type requires a size (number of
1747 elements) and an underlying primitive data type. Vectors must have a power
1748 of two length (1, 2, 4, 8, 16 ...). Vector types are considered
1749 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1750
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1751<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1752<pre>
1753 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1754</pre>
1755
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1756<p>The number of elements is a constant integer value; elementtype may be any
1757 integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1758
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1759<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1760<table class="layout">
1761 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1762 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1763 <td class="left">Vector of 4 32-bit integer values.</td>
1764 </tr>
1765 <tr class="layout">
1766 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1767 <td class="left">Vector of 8 32-bit floating-point values.</td>
1768 </tr>
1769 <tr class="layout">
1770 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1771 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1772 </tr>
1773</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1774
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1775<p>Note that the code generator does not yet support large vector types to be
1776 used as function return types. The specific limit on how large a vector
1777 return type codegen can currently handle is target-dependent; currently it's
1778 often a few times longer than a hardware vector register.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1779
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1780</div>
1781
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1782<!-- _______________________________________________________________________ -->
1783<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1784<div class="doc_text">
1785
1786<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1787<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1788 corresponds (for example) to the C notion of a forward declared structure
1789 type. In LLVM, opaque types can eventually be resolved to any type (not just
1790 a structure type).</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1791
1792<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1793<pre>
1794 opaque
1795</pre>
1796
1797<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1798<table class="layout">
1799 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1800 <td class="left"><tt>opaque</tt></td>
1801 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1802 </tr>
1803</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1804
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1805</div>
1806
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1807<!-- ======================================================================= -->
1808<div class="doc_subsection">
1809 <a name="t_uprefs">Type Up-references</a>
1810</div>
1811
1812<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1813
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1814<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1815<p>An "up reference" allows you to refer to a lexically enclosing type without
1816 requiring it to have a name. For instance, a structure declaration may
1817 contain a pointer to any of the types it is lexically a member of. Example
1818 of up references (with their equivalent as named type declarations)
1819 include:</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1820
1821<pre>
Chris Lattner3060f5b2009-02-09 10:00:56 +0000[diff] [blame]1822 { \2 * } %x = type { %x* }
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1823 { \2 }* %y = type { %y }*
1824 \1* %z = type %z*
1825</pre>
1826
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1827<p>An up reference is needed by the asmprinter for printing out cyclic types
1828 when there is no declared name for a type in the cycle. Because the
1829 asmprinter does not want to print out an infinite type string, it needs a
1830 syntax to handle recursive types that have no names (all names are optional
1831 in llvm IR).</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1832
1833<h5>Syntax:</h5>
1834<pre>
1835 \&lt;level&gt;
1836</pre>
1837
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1838<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]1839
1840<h5>Examples:</h5>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1841<table class="layout">
1842 <tr class="layout">
1843 <td class="left"><tt>\1*</tt></td>
1844 <td class="left">Self-referential pointer.</td>
1845 </tr>
1846 <tr class="layout">
1847 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1848 <td class="left">Recursive structure where the upref refers to the out-most
1849 structure.</td>
1850 </tr>
1851</table>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]1852
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1853</div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1854
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1855<!-- *********************************************************************** -->
1856<div class="doc_section"> <a name="constants">Constants</a> </div>
1857<!-- *********************************************************************** -->
1858
1859<div class="doc_text">
1860
1861<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1862 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1863
1864</div>
1865
1866<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1867<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1868
1869<div class="doc_text">
1870
1871<dl>
1872 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1873 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1874 constants of the <tt><a href="#t_primitive">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1875
1876 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1877 <dd>Standard integers (such as '4') are constants of
1878 the <a href="#t_integer">integer</a> type. Negative numbers may be used
1879 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1880
1881 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1882 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1883 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
1884 notation (see below). The assembler requires the exact decimal value of a
1885 floating-point constant. For example, the assembler accepts 1.25 but
1886 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1887 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1888
1889 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1890 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1891 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1892</dl>
1893
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1894<p>The one non-intuitive notation for constants is the hexadecimal form of
1895 floating point constants. For example, the form '<tt>double
1896 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
1897 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
1898 constants are required (and the only time that they are generated by the
1899 disassembler) is when a floating point constant must be emitted but it cannot
1900 be represented as a decimal floating point number in a reasonable number of
1901 digits. For example, NaN's, infinities, and other special values are
1902 represented in their IEEE hexadecimal format so that assembly and disassembly
1903 do not cause any bits to change in the constants.</p>
1904
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]1905<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1906 represented using the 16-digit form shown above (which matches the IEEE754
1907 representation for double); float values must, however, be exactly
1908 representable as IEE754 single precision. Hexadecimal format is always used
1909 for long double, and there are three forms of long double. The 80-bit format
1910 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
1911 The 128-bit format used by PowerPC (two adjacent doubles) is represented
1912 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
1913 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
1914 currently supported target uses this format. Long doubles will only work if
1915 they match the long double format on your target. All hexadecimal formats
1916 are big-endian (sign bit at the left).</p>
1917
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1918</div>
1919
1920<!-- ======================================================================= -->
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]1921<div class="doc_subsection">
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]1922<a name="aggregateconstants"></a> <!-- old anchor -->
1923<a name="complexconstants">Complex Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1924</div>
1925
1926<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1927
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]1928<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1929 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1930
1931<dl>
1932 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1933 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1934 type definitions (a comma separated list of elements, surrounded by braces
1935 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1936 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
1937 Structure constants must have <a href="#t_struct">structure type</a>, and
1938 the number and types of elements must match those specified by the
1939 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1940
1941 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1942 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1943 definitions (a comma separated list of elements, surrounded by square
1944 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
1945 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
1946 the number and types of elements must match those specified by the
1947 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1948
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1949 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1950 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1951 definitions (a comma separated list of elements, surrounded by
1952 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
1953 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
1954 have <a href="#t_vector">vector type</a>, and the number and types of
1955 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1956
1957 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1958 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1959 value to zero of <em>any</em> type, including scalar and aggregate types.
1960 This is often used to avoid having to print large zero initializers
1961 (e.g. for large arrays) and is always exactly equivalent to using explicit
1962 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]1963
1964 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]1965 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1966 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
1967 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
1968 be interpreted as part of the instruction stream, metadata is a place to
1969 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1970</dl>
1971
1972</div>
1973
1974<!-- ======================================================================= -->
1975<div class="doc_subsection">
1976 <a name="globalconstants">Global Variable and Function Addresses</a>
1977</div>
1978
1979<div class="doc_text">
1980
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1981<p>The addresses of <a href="#globalvars">global variables</a>
1982 and <a href="#functionstructure">functions</a> are always implicitly valid
1983 (link-time) constants. These constants are explicitly referenced when
1984 the <a href="#identifiers">identifier for the global</a> is used and always
1985 have <a href="#t_pointer">pointer</a> type. For example, the following is a
1986 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1987
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1988<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1989<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1990@X = global i32 17
1991@Y = global i32 42
1992@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1993</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1994</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1995
1996</div>
1997
1998<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1999<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2000<div class="doc_text">
2001
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2002<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has no
2003 specific value. Undefined values may be of any type and be used anywhere a
2004 constant is permitted.</p>
2005
2006<p>Undefined values indicate to the compiler that the program is well defined no
2007 matter what value is used, giving the compiler more freedom to optimize.</p>
2008
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2009</div>
2010
2011<!-- ======================================================================= -->
2012<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2013</div>
2014
2015<div class="doc_text">
2016
2017<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2018 to be used as constants. Constant expressions may be of
2019 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2020 operation that does not have side effects (e.g. load and call are not
2021 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2022
2023<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2024 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2025 <dd>Truncate a constant to another type. The bit size of CST must be larger
2026 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2027
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2028 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2029 <dd>Zero extend a constant to another type. The bit size of CST must be
2030 smaller or equal to the bit size of TYPE. Both types must be
2031 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2032
2033 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2034 <dd>Sign extend a constant to another type. The bit size of CST must be
2035 smaller or equal to the bit size of TYPE. Both types must be
2036 integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2037
2038 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2039 <dd>Truncate a floating point constant to another floating point type. The
2040 size of CST must be larger than the size of TYPE. Both types must be
2041 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2042
2043 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2044 <dd>Floating point extend a constant to another type. The size of CST must be
2045 smaller or equal to the size of TYPE. Both types must be floating
2046 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2047
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]2048 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2049 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2050 constant. TYPE must be a scalar or vector integer type. CST must be of
2051 scalar or vector floating point type. Both CST and TYPE must be scalars,
2052 or vectors of the same number of elements. If the value won't fit in the
2053 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2054
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2055 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2056 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2057 constant. TYPE must be a scalar or vector integer type. CST must be of
2058 scalar or vector floating point type. Both CST and TYPE must be scalars,
2059 or vectors of the same number of elements. If the value won't fit in the
2060 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2061
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2062 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2063 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2064 constant. TYPE must be a scalar or vector floating point type. CST must be
2065 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2066 vectors of the same number of elements. If the value won't fit in the
2067 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2068
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2069 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2070 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2071 constant. TYPE must be a scalar or vector floating point type. CST must be
2072 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2073 vectors of the same number of elements. If the value won't fit in the
2074 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2075
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2076 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2077 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2078 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2079 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2080 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2081
2082 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2083 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2084 type. CST must be of integer type. The CST value is zero extended,
2085 truncated, or unchanged to make it fit in a pointer size. This one is
2086 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2087
2088 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2089 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2090 are the same as those for the <a href="#i_bitcast">bitcast
2091 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2092
2093 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2094 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2095 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2096 instruction, the index list may have zero or more indexes, which are
2097 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2098
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2099 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2100 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2101
2102 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2103 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2104
2105 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2106 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2107
2108 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2109 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2110 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2111
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]2112 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2113 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2114 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2115
2116 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2117 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2118 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2119
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2120 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2121 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2122 be any of the <a href="#binaryops">binary</a>
2123 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2124 on operands are the same as those for the corresponding instruction
2125 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2126</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2127
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2128</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2129
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2130<!-- ======================================================================= -->
2131<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
2132</div>
2133
2134<div class="doc_text">
2135
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2136<p>Embedded metadata provides a way to attach arbitrary data to the instruction
2137 stream without affecting the behaviour of the program. There are two
2138 metadata primitives, strings and nodes. All metadata has the
2139 <tt>metadata</tt> type and is identified in syntax by a preceding exclamation
2140 point ('<tt>!</tt>').</p>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2141
2142<p>A metadata string is a string surrounded by double quotes. It can contain
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2143 any character by escaping non-printable characters with "\xx" where "xx" is
2144 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2145
2146<p>Metadata nodes are represented with notation similar to structure constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2147 (a comma separated list of elements, surrounded by braces and preceeded by an
2148 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2149 10}</tt>".</p>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2150
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2151<p>A metadata node will attempt to track changes to the values it holds. In the
2152 event that a value is deleted, it will be replaced with a typeless
2153 "<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewyckycb337992009-05-10 20:57:05 +0000[diff] [blame]2154
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2155<p>Optimizations may rely on metadata to provide additional information about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2156 the program that isn't available in the instructions, or that isn't easily
2157 computable. Similarly, the code generator may expect a certain metadata
2158 format to be used to express debugging information.</p>
2159
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2160</div>
2161
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2162<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2163<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2164<!-- *********************************************************************** -->
2165
2166<!-- ======================================================================= -->
2167<div class="doc_subsection">
2168<a name="inlineasm">Inline Assembler Expressions</a>
2169</div>
2170
2171<div class="doc_text">
2172
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2173<p>LLVM supports inline assembler expressions (as opposed
2174 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2175 a special value. This value represents the inline assembler as a string
2176 (containing the instructions to emit), a list of operand constraints (stored
2177 as a string), and a flag that indicates whether or not the inline asm
2178 expression has side effects. An example inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2179
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2180<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2181<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2182i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2183</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2184</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2185
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2186<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2187 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2188 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2189
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2190<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2191<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2192%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]2193</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2194</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2195
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2196<p>Inline asms with side effects not visible in the constraint list must be
2197 marked as having side effects. This is done through the use of the
2198 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2199
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2200<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2201<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2202call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2203</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2204</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2205
2206<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2207 documented here. Constraints on what can be done (e.g. duplication, moving,
2208 etc need to be documented). This is probably best done by reference to
2209 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2210
2211</div>
2212
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2213
2214<!-- *********************************************************************** -->
2215<div class="doc_section">
2216 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2217</div>
2218<!-- *********************************************************************** -->
2219
2220<p>LLVM has a number of "magic" global variables that contain data that affect
2221code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2222of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2223section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2224by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2225
2226<!-- ======================================================================= -->
2227<div class="doc_subsection">
2228<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2229</div>
2230
2231<div class="doc_text">
2232
2233<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2234href="#linkage_appending">appending linkage</a>. This array contains a list of
2235pointers to global variables and functions which may optionally have a pointer
2236cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2237
2238<pre>
2239 @X = global i8 4
2240 @Y = global i32 123
2241
2242 @llvm.used = appending global [2 x i8*] [
2243 i8* @X,
2244 i8* bitcast (i32* @Y to i8*)
2245 ], section "llvm.metadata"
2246</pre>
2247
2248<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2249compiler, assembler, and linker are required to treat the symbol as if there is
2250a reference to the global that it cannot see. For example, if a variable has
2251internal linkage and no references other than that from the <tt>@llvm.used</tt>
2252list, it cannot be deleted. This is commonly used to represent references from
2253inline asms and other things the compiler cannot "see", and corresponds to
2254"attribute((used))" in GNU C.</p>
2255
2256<p>On some targets, the code generator must emit a directive to the assembler or
2257object file to prevent the assembler and linker from molesting the symbol.</p>
2258
2259</div>
2260
2261<!-- ======================================================================= -->
2262<div class="doc_subsection">
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2263<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2264</div>
2265
2266<div class="doc_text">
2267
2268<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2269<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2270touching the symbol. On targets that support it, this allows an intelligent
2271linker to optimize references to the symbol without being impeded as it would be
2272by <tt>@llvm.used</tt>.</p>
2273
2274<p>This is a rare construct that should only be used in rare circumstances, and
2275should not be exposed to source languages.</p>
2276
2277</div>
2278
2279<!-- ======================================================================= -->
2280<div class="doc_subsection">
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2281<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2282</div>
2283
2284<div class="doc_text">
2285
2286<p>TODO: Describe this.</p>
2287
2288</div>
2289
2290<!-- ======================================================================= -->
2291<div class="doc_subsection">
2292<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2293</div>
2294
2295<div class="doc_text">
2296
2297<p>TODO: Describe this.</p>
2298
2299</div>
2300
2301
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2302<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2303<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2304<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2305
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2306<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2307
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2308<p>The LLVM instruction set consists of several different classifications of
2309 instructions: <a href="#terminators">terminator
2310 instructions</a>, <a href="#binaryops">binary instructions</a>,
2311 <a href="#bitwiseops">bitwise binary instructions</a>,
2312 <a href="#memoryops">memory instructions</a>, and
2313 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2314
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2315</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2316
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2317<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2318<div class="doc_subsection"> <a name="terminators">Terminator
2319Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2320
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2321<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2322
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2323<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2324 in a program ends with a "Terminator" instruction, which indicates which
2325 block should be executed after the current block is finished. These
2326 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2327 control flow, not values (the one exception being the
2328 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2329
2330<p>There are six different terminator instructions: the
2331 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2332 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2333 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
2334 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2335 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2336 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2337
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2338</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2339
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2340<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2341<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2342Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2343
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2344<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2345
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2346<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2347<pre>
2348 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]2349 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2350</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2351
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2352<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2353<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2354 a value) from a function back to the caller.</p>
2355
2356<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2357 value and then causes control flow, and one that just causes control flow to
2358 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2359
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2360<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2361<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2362 return value. The type of the return value must be a
2363 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2364
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2365<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2366 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2367 value or a return value with a type that does not match its type, or if it
2368 has a void return type and contains a '<tt>ret</tt>' instruction with a
2369 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2370
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2371<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2372<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2373 the calling function's context. If the caller is a
2374 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2375 instruction after the call. If the caller was an
2376 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2377 the beginning of the "normal" destination block. If the instruction returns
2378 a value, that value shall set the call or invoke instruction's return
2379 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2380
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2381<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2382<pre>
2383 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2384 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]2385 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]2386</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2387
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2388<p>Note that the code generator does not yet fully support large
2389 return values. The specific sizes that are currently supported are
2390 dependent on the target. For integers, on 32-bit targets the limit
2391 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2392 For aggregate types, the current limits are dependent on the element
2393 types; for example targets are often limited to 2 total integer
2394 elements and 2 total floating-point elements.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2395
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2396</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2397<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2398<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2399
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2400<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2401
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2402<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2403<pre>
2404 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]2405</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2406
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2407<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2408<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2409 different basic block in the current function. There are two forms of this
2410 instruction, corresponding to a conditional branch and an unconditional
2411 branch.</p>
2412
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2413<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2414<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2415 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2416 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2417 target.</p>
2418
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2419<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2420<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2421 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2422 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2423 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2424
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2425<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2426<pre>
2427Test:
2428 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2429 br i1 %cond, label %IfEqual, label %IfUnequal
2430IfEqual:
2431 <a href="#i_ret">ret</a> i32 1
2432IfUnequal:
2433 <a href="#i_ret">ret</a> i32 0
2434</pre>
2435
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2436</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2437
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2438<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2439<div class="doc_subsubsection">
2440 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2441</div>
2442
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2443<div class="doc_text">
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2444
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2445<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2446<pre>
2447 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2448</pre>
2449
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2450<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2451<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]2452 several different places. It is a generalization of the '<tt>br</tt>'
2453 instruction, allowing a branch to occur to one of many possible
2454 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2455
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2456<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2457<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2458 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2459 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2460 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2461
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2462<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2463<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2464 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2465 is searched for the given value. If the value is found, control flow is
2466 transfered to the corresponding destination; otherwise, control flow is
2467 transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2468
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2469<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2470<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2471 <tt>switch</tt> instruction, this instruction may be code generated in
2472 different ways. For example, it could be generated as a series of chained
2473 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2474
2475<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2476<pre>
2477 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2478 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2479 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2480
2481 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2482 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]2483
2484 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2485 switch i32 %val, label %otherwise [ i32 0, label %onzero
2486 i32 1, label %onone
2487 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2488</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2489
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2490</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2491
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2492<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2493<div class="doc_subsubsection">
2494 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2495</div>
2496
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2497<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2498
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2499<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2500<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2501 &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]2502 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2503</pre>
2504
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2505<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2506<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2507 function, with the possibility of control flow transfer to either the
2508 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2509 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2510 control flow will return to the "normal" label. If the callee (or any
2511 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2512 instruction, control is interrupted and continued at the dynamically nearest
2513 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2514
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2515<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2516<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2517
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2518<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2519 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2520 convention</a> the call should use. If none is specified, the call
2521 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2522
2523 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2524 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2525 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]2526
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2527 <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]2528 function value being invoked. In most cases, this is a direct function
2529 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2530 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2531
2532 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2533 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2534
2535 <li>'<tt>function args</tt>': argument list whose types match the function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2536 signature argument types. If the function signature indicates the
2537 function accepts a variable number of arguments, the extra arguments can
2538 be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2539
2540 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2541 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2542
2543 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2544 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2545
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]2546 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2547 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2548 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2549</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2550
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2551<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2552<p>This instruction is designed to operate as a standard
2553 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2554 primary difference is that it establishes an association with a label, which
2555 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2556
2557<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2558 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2559 exception. Additionally, this is important for implementation of
2560 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2561
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2562<p>For the purposes of the SSA form, the definition of the value returned by the
2563 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2564 block to the "normal" label. If the callee unwinds then no return value is
2565 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]2566
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2567<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]2568<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2569 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2570 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]2571 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2572 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2573</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2574
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2575</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2576
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2577<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2578
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2579<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2580Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2581
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2582<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2583
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2584<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2585<pre>
2586 unwind
2587</pre>
2588
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2589<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2590<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2591 at the first callee in the dynamic call stack which used
2592 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
2593 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2594
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]2595<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]2596<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2597 immediately halt. The dynamic call stack is then searched for the
2598 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
2599 Once found, execution continues at the "exceptional" destination block
2600 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
2601 instruction in the dynamic call chain, undefined behavior results.</p>
2602
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2603</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2604
2605<!-- _______________________________________________________________________ -->
2606
2607<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2608Instruction</a> </div>
2609
2610<div class="doc_text">
2611
2612<h5>Syntax:</h5>
2613<pre>
2614 unreachable
2615</pre>
2616
2617<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2618<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2619 instruction is used to inform the optimizer that a particular portion of the
2620 code is not reachable. This can be used to indicate that the code after a
2621 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2622
2623<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2624<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2625
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]2626</div>
2627
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2628<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2629<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2630
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2631<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2632
2633<p>Binary operators are used to do most of the computation in a program. They
2634 require two operands of the same type, execute an operation on them, and
2635 produce a single value. The operands might represent multiple data, as is
2636 the case with the <a href="#t_vector">vector</a> data type. The result value
2637 has the same type as its operands.</p>
2638
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2639<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2640
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2641</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2642
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2643<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2644<div class="doc_subsubsection">
2645 <a name="i_add">'<tt>add</tt>' Instruction</a>
2646</div>
2647
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2648<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2649
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2650<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2651<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2652 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2653 &lt;result&gt; = nuw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2654 &lt;result&gt; = nsw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2655 &lt;result&gt; = nuw nsw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2656</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2657
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2658<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2659<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2660
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2661<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2662<p>The two arguments to the '<tt>add</tt>' instruction must
2663 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2664 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2665
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2666<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2667<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2668
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2669<p>If the sum has unsigned overflow, the result returned is the mathematical
2670 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]2671
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2672<p>Because LLVM integers use a two's complement representation, this instruction
2673 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2674
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2675<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2676 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2677 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
2678 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2679
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2680<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2681<pre>
2682 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2683</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2684
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2685</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2686
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2687<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2688<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2689 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
2690</div>
2691
2692<div class="doc_text">
2693
2694<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2695<pre>
2696 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2697</pre>
2698
2699<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2700<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
2701
2702<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2703<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2704 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2705 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2706
2707<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2708<p>The value produced is the floating point sum of the two operands.</p>
2709
2710<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2711<pre>
2712 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
2713</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2714
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2715</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2716
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2717<!-- _______________________________________________________________________ -->
2718<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2719 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2720</div>
2721
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2722<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2723
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2724<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2725<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2726 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2727 &lt;result&gt; = nuw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2728 &lt;result&gt; = nsw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2729 &lt;result&gt; = nuw nsw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2730</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2731
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2732<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2733<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2734 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2735
2736<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2737 '<tt>neg</tt>' instruction present in most other intermediate
2738 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2739
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2740<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2741<p>The two arguments to the '<tt>sub</tt>' instruction must
2742 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2743 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2744
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2745<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2746<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2747
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2748<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2749 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
2750 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2751
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2752<p>Because LLVM integers use a two's complement representation, this instruction
2753 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2754
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2755<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2756 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2757 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
2758 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2759
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2760<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2761<pre>
2762 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2763 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2764</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2765
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2766</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2767
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2768<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2769<div class="doc_subsubsection">
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2770 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
2771</div>
2772
2773<div class="doc_text">
2774
2775<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2776<pre>
2777 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2778</pre>
2779
2780<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2781<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2782 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2783
2784<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2785 '<tt>fneg</tt>' instruction present in most other intermediate
2786 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2787
2788<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2789<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2790 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2791 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2792
2793<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2794<p>The value produced is the floating point difference of the two operands.</p>
2795
2796<h5>Example:</h5>
2797<pre>
2798 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
2799 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
2800</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2801
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2802</div>
2803
2804<!-- _______________________________________________________________________ -->
2805<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2806 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2807</div>
2808
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2809<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2810
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2811<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2812<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2813 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2814 &lt;result&gt; = nuw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2815 &lt;result&gt; = nsw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2816 &lt;result&gt; = nuw nsw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2817</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2818
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2819<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2820<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2821
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2822<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2823<p>The two arguments to the '<tt>mul</tt>' instruction must
2824 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2825 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2826
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2827<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2828<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2829
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2830<p>If the result of the multiplication has unsigned overflow, the result
2831 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
2832 width of the result.</p>
2833
2834<p>Because LLVM integers use a two's complement representation, and the result
2835 is the same width as the operands, this instruction returns the correct
2836 result for both signed and unsigned integers. If a full product
2837 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
2838 be sign-extended or zero-extended as appropriate to the width of the full
2839 product.</p>
2840
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]2841<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2842 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2843 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
2844 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2845
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2846<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2847<pre>
2848 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2849</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2850
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2851</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2852
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2853<!-- _______________________________________________________________________ -->
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2854<div class="doc_subsubsection">
2855 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
2856</div>
2857
2858<div class="doc_text">
2859
2860<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2861<pre>
2862 &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]2863</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2864
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2865<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2866<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2867
2868<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2869<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2870 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2871 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2872
2873<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2874<p>The value produced is the floating point product of the two operands.</p>
2875
2876<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2877<pre>
2878 &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]2879</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2880
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]2881</div>
2882
2883<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2884<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2885</a></div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2886
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2887<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2888
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2889<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2890<pre>
2891 &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]2892</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2893
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2894<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2895<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2896
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2897<h5>Arguments:</h5>
2898<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2899 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2900 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2901
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2902<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2903<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2904
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2905<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2906 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2907
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2908<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2909
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2910<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2911<pre>
2912 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2913</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2914
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2915</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2916
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2917<!-- _______________________________________________________________________ -->
2918<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2919</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2920
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2921<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2922
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2923<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2924<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2925 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2926 &lt;result&gt; = exact sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2927</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2928
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2929<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2930<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2931
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2932<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2933<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2934 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2935 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2936
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2937<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2938<p>The value produced is the signed integer quotient of the two operands rounded
2939 towards zero.</p>
2940
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2941<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2942 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2943
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]2944<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2945 undefined behavior; this is a rare case, but can occur, for example, by doing
2946 a 32-bit division of -2147483648 by -1.</p>
2947
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]2948<p>If the <tt>exact</tt> keyword is present, the result value of the
2949 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
2950 would occur.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]2951
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2952<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2953<pre>
2954 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2955</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2956
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2957</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2958
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2959<!-- _______________________________________________________________________ -->
2960<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2961Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2962
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2963<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2964
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2965<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2966<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]2967 &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]2968</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2969
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2970<h5>Overview:</h5>
2971<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2972
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2973<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2974<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2975 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2976 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2977
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2978<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2979<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2980
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2981<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2982<pre>
2983 &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]2984</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2985
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2986</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]2987
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2988<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2989<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2990</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2991
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2992<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2993
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2994<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2995<pre>
2996 &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]2997</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2998
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2999<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3000<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3001 division of its two arguments.</p>
3002
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3003<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3004<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3005 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3006 values. Both arguments must have identical types.</p>
3007
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3008<h5>Semantics:</h5>
3009<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3010 This instruction always performs an unsigned division to get the
3011 remainder.</p>
3012
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3013<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3014 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3015
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3016<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3017
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3018<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3019<pre>
3020 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3021</pre>
3022
3023</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3024
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3025<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3026<div class="doc_subsubsection">
3027 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3028</div>
3029
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3030<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3031
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3032<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3033<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3034 &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]3035</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3036
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3037<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3038<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3039 division of its two operands. This instruction can also take
3040 <a href="#t_vector">vector</a> versions of the values in which case the
3041 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3042
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3043<h5>Arguments:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3044<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3045 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3046 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3047
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3048<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3049<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3050 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3051 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3052 a value. For more information about the difference,
3053 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3054 Math Forum</a>. For a table of how this is implemented in various languages,
3055 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3056 Wikipedia: modulo operation</a>.</p>
3057
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3058<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3059 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3060
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3061<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3062 Overflow also leads to undefined behavior; this is a rare case, but can
3063 occur, for example, by taking the remainder of a 32-bit division of
3064 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3065 lets srem be implemented using instructions that return both the result of
3066 the division and the remainder.)</p>
3067
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3068<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3069<pre>
3070 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3071</pre>
3072
3073</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3074
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3075<!-- _______________________________________________________________________ -->
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3076<div class="doc_subsubsection">
3077 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3078
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3079<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3080
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3081<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3082<pre>
3083 &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]3084</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3085
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3086<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3087<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3088 its two operands.</p>
3089
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3090<h5>Arguments:</h5>
3091<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3092 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3093 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3094
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3095<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3096<p>This instruction returns the <i>remainder</i> of a division. The remainder
3097 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3098
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3099<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3100<pre>
3101 &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]3102</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3103
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3104</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3105
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3106<!-- ======================================================================= -->
3107<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3108Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3109
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3110<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3111
3112<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3113 program. They are generally very efficient instructions and can commonly be
3114 strength reduced from other instructions. They require two operands of the
3115 same type, execute an operation on them, and produce a single value. The
3116 resulting value is the same type as its operands.</p>
3117
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3118</div>
3119
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3120<!-- _______________________________________________________________________ -->
3121<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3122Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3123
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3124<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3125
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3126<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3127<pre>
3128 &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]3129</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3130
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3131<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3132<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3133 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3134
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3135<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3136<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3137 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3138 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3139
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3140<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3141<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3142 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3143 is (statically or dynamically) negative or equal to or larger than the number
3144 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3145 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3146 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3147
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3148<h5>Example:</h5>
3149<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3150 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3151 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3152 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3153 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3154 &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]3155</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3156
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3157</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3158
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3159<!-- _______________________________________________________________________ -->
3160<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3161Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3162
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3163<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3164
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3165<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3166<pre>
3167 &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]3168</pre>
3169
3170<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3171<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3172 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3173
3174<h5>Arguments:</h5>
3175<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3176 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3177 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3178
3179<h5>Semantics:</h5>
3180<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3181 significant bits of the result will be filled with zero bits after the shift.
3182 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3183 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3184 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3185 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3186
3187<h5>Example:</h5>
3188<pre>
3189 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3190 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3191 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3192 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3193 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3194 &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]3195</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3196
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3197</div>
3198
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3199<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3200<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3201Instruction</a> </div>
3202<div class="doc_text">
3203
3204<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3205<pre>
3206 &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]3207</pre>
3208
3209<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3210<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3211 operand shifted to the right a specified number of bits with sign
3212 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3213
3214<h5>Arguments:</h5>
3215<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3216 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3217 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3218
3219<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3220<p>This instruction always performs an arithmetic shift right operation, The
3221 most significant bits of the result will be filled with the sign bit
3222 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3223 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3224 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3225 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3226
3227<h5>Example:</h5>
3228<pre>
3229 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3230 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3231 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3232 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3233 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3234 &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]3235</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3236
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3237</div>
3238
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3239<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3240<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3241Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3242
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3243<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3244
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3245<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3246<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3247 &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]3248</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3249
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3250<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3251<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3252 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3253
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3254<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3255<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3256 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3257 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3258
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3259<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3260<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3261
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3262<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3263 <tbody>
3264 <tr>
3265 <td>In0</td>
3266 <td>In1</td>
3267 <td>Out</td>
3268 </tr>
3269 <tr>
3270 <td>0</td>
3271 <td>0</td>
3272 <td>0</td>
3273 </tr>
3274 <tr>
3275 <td>0</td>
3276 <td>1</td>
3277 <td>0</td>
3278 </tr>
3279 <tr>
3280 <td>1</td>
3281 <td>0</td>
3282 <td>0</td>
3283 </tr>
3284 <tr>
3285 <td>1</td>
3286 <td>1</td>
3287 <td>1</td>
3288 </tr>
3289 </tbody>
3290</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3291
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3292<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3293<pre>
3294 &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]3295 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3296 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3297</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3298</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3299<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3300<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3301
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3302<div class="doc_text">
3303
3304<h5>Syntax:</h5>
3305<pre>
3306 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3307</pre>
3308
3309<h5>Overview:</h5>
3310<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3311 two operands.</p>
3312
3313<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3314<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3315 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3316 values. Both arguments must have identical types.</p>
3317
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3318<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3319<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3320
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3321<table border="1" cellspacing="0" cellpadding="4">
3322 <tbody>
3323 <tr>
3324 <td>In0</td>
3325 <td>In1</td>
3326 <td>Out</td>
3327 </tr>
3328 <tr>
3329 <td>0</td>
3330 <td>0</td>
3331 <td>0</td>
3332 </tr>
3333 <tr>
3334 <td>0</td>
3335 <td>1</td>
3336 <td>1</td>
3337 </tr>
3338 <tr>
3339 <td>1</td>
3340 <td>0</td>
3341 <td>1</td>
3342 </tr>
3343 <tr>
3344 <td>1</td>
3345 <td>1</td>
3346 <td>1</td>
3347 </tr>
3348 </tbody>
3349</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3350
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3351<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3352<pre>
3353 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3354 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3355 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3356</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3357
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3358</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3359
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3360<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3361<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3362Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3363
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3364<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3365
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3366<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3367<pre>
3368 &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]3369</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3370
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3371<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3372<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3373 its two operands. The <tt>xor</tt> is used to implement the "one's
3374 complement" operation, which is the "~" operator in C.</p>
3375
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3376<h5>Arguments:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3377<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3378 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3379 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3380
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3381<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3382<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3383
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3384<table border="1" cellspacing="0" cellpadding="4">
3385 <tbody>
3386 <tr>
3387 <td>In0</td>
3388 <td>In1</td>
3389 <td>Out</td>
3390 </tr>
3391 <tr>
3392 <td>0</td>
3393 <td>0</td>
3394 <td>0</td>
3395 </tr>
3396 <tr>
3397 <td>0</td>
3398 <td>1</td>
3399 <td>1</td>
3400 </tr>
3401 <tr>
3402 <td>1</td>
3403 <td>0</td>
3404 <td>1</td>
3405 </tr>
3406 <tr>
3407 <td>1</td>
3408 <td>1</td>
3409 <td>0</td>
3410 </tr>
3411 </tbody>
3412</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3413
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3414<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3415<pre>
3416 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3417 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3418 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3419 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3420</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3421
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3422</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3423
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3424<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3425<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3426 <a name="vectorops">Vector Operations</a>
3427</div>
3428
3429<div class="doc_text">
3430
3431<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3432 target-independent manner. These instructions cover the element-access and
3433 vector-specific operations needed to process vectors effectively. While LLVM
3434 does directly support these vector operations, many sophisticated algorithms
3435 will want to use target-specific intrinsics to take full advantage of a
3436 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3437
3438</div>
3439
3440<!-- _______________________________________________________________________ -->
3441<div class="doc_subsubsection">
3442 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3443</div>
3444
3445<div class="doc_text">
3446
3447<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3448<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3449 &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]3450</pre>
3451
3452<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3453<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3454 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3455
3456
3457<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3458<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3459 of <a href="#t_vector">vector</a> type. The second operand is an index
3460 indicating the position from which to extract the element. The index may be
3461 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3462
3463<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3464<p>The result is a scalar of the same type as the element type of
3465 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3466 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3467 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3468
3469<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3470<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3471 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3472</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3473
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3474</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3475
3476<!-- _______________________________________________________________________ -->
3477<div class="doc_subsubsection">
3478 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3479</div>
3480
3481<div class="doc_text">
3482
3483<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3484<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]3485 &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]3486</pre>
3487
3488<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3489<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3490 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3491
3492<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3493<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3494 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3495 whose type must equal the element type of the first operand. The third
3496 operand is an index indicating the position at which to insert the value.
3497 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3498
3499<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3500<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3501 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3502 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3503 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3504
3505<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3506<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3507 %result = 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]3508</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3509
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3510</div>
3511
3512<!-- _______________________________________________________________________ -->
3513<div class="doc_subsubsection">
3514 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3515</div>
3516
3517<div class="doc_text">
3518
3519<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3520<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3521 &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]3522</pre>
3523
3524<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3525<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3526 from two input vectors, returning a vector with the same element type as the
3527 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3528
3529<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3530<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3531 with types that match each other. The third argument is a shuffle mask whose
3532 element type is always 'i32'. The result of the instruction is a vector
3533 whose length is the same as the shuffle mask and whose element type is the
3534 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3535
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3536<p>The shuffle mask operand is required to be a constant vector with either
3537 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3538
3539<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3540<p>The elements of the two input vectors are numbered from left to right across
3541 both of the vectors. The shuffle mask operand specifies, for each element of
3542 the result vector, which element of the two input vectors the result element
3543 gets. The element selector may be undef (meaning "don't care") and the
3544 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3545
3546<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3547<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3548 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3549 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3550 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3551 &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.
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]3552 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3553 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3554 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3555 &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]3556</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3557
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3558</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]3559
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]3560<!-- ======================================================================= -->
3561<div class="doc_subsection">
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3562 <a name="aggregateops">Aggregate Operations</a>
3563</div>
3564
3565<div class="doc_text">
3566
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3567<p>LLVM supports several instructions for working with aggregate values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3568
3569</div>
3570
3571<!-- _______________________________________________________________________ -->
3572<div class="doc_subsubsection">
3573 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3574</div>
3575
3576<div class="doc_text">
3577
3578<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3579<pre>
3580 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3581</pre>
3582
3583<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3584<p>The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3585 or array element from an aggregate value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3586
3587<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3588<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
3589 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3590 operands are constant indices to specify which value to extract in a similar
3591 manner as indices in a
3592 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3593
3594<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3595<p>The result is the value at the position in the aggregate specified by the
3596 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3597
3598<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3599<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3600 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3601</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3602
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3603</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3604
3605<!-- _______________________________________________________________________ -->
3606<div class="doc_subsubsection">
3607 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3608</div>
3609
3610<div class="doc_text">
3611
3612<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3613<pre>
Dan Gohman81a0c0b2008-05-31 00:58:22 +0000[diff] [blame]3614 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;val&gt;, &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3615</pre>
3616
3617<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3618<p>The '<tt>insertvalue</tt>' instruction inserts a value into a struct field or
3619 array element in an aggregate.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3620
3621
3622<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3623<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
3624 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3625 second operand is a first-class value to insert. The following operands are
3626 constant indices indicating the position at which to insert the value in a
3627 similar manner as indices in a
3628 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
3629 value to insert must have the same type as the value identified by the
3630 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3631
3632<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3633<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
3634 that of <tt>val</tt> except that the value at the position specified by the
3635 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3636
3637<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3638<pre>
Dan Gohman52bb2db2008-06-23 15:26:37 +0000[diff] [blame]3639 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3640</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3641
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]3642</div>
3643
3644
3645<!-- ======================================================================= -->
3646<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3647 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3648</div>
3649
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3650<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3651
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3652<p>A key design point of an SSA-based representation is how it represents
3653 memory. In LLVM, no memory locations are in SSA form, which makes things
3654 very simple. This section describes how to read, write, allocate, and free
3655 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3656
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3657</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3658
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3659<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3660<div class="doc_subsubsection">
3661 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3662</div>
3663
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3664<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3665
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3666<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3667<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3668 &lt;result&gt; = malloc &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]3669</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3670
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3671<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3672<p>The '<tt>malloc</tt>' instruction allocates memory from the system heap and
3673 returns a pointer to it. The object is always allocated in the generic
3674 address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3675
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3676<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3677<p>The '<tt>malloc</tt>' instruction allocates
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3678 <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory from the operating
3679 system and returns a pointer of the appropriate type to the program. If
3680 "NumElements" is specified, it is the number of elements allocated, otherwise
3681 "NumElements" is defaulted to be one. If a constant alignment is specified,
3682 the value result of the allocation is guaranteed to be aligned to at least
3683 that boundary. If not specified, or if zero, the target can choose to align
3684 the allocation on any convenient boundary compatible with the type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3685
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3686<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3687
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3688<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3689<p>Memory is allocated using the system "<tt>malloc</tt>" function, and a
3690 pointer is returned. The result of a zero byte allocation is undefined. The
3691 result is null if there is insufficient memory available.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3692
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3693<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3694<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3695 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3696
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3697 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3698 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3699 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3700 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3701 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3702</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3703
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3704<p>Note that the code generator does not yet respect the alignment value.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3705
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3706</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3707
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3708<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3709<div class="doc_subsubsection">
3710 <a name="i_free">'<tt>free</tt>' Instruction</a>
3711</div>
3712
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3713<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3714
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3715<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3716<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3717 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3718</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3719
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3720<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3721<p>The '<tt>free</tt>' instruction returns memory back to the unused memory heap
3722 to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3723
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3724<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3725<p>'<tt>value</tt>' shall be a pointer value that points to a value that was
3726 allocated with the '<tt><a href="#i_malloc">malloc</a></tt>' instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3727
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3728<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3729<p>Access to the memory pointed to by the pointer is no longer defined after
3730 this instruction executes. If the pointer is null, the operation is a
3731 noop.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3732
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3733<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3734<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3735 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3736 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3737</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3738
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3739</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3740
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3741<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3742<div class="doc_subsubsection">
3743 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3744</div>
3745
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3746<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3747
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3748<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3749<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3750 &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]3751</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3752
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3753<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3754<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3755 currently executing function, to be automatically released when this function
3756 returns to its caller. The object is always allocated in the generic address
3757 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3758
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3759<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3760<p>The '<tt>alloca</tt>' instruction
3761 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
3762 runtime stack, returning a pointer of the appropriate type to the program.
3763 If "NumElements" is specified, it is the number of elements allocated,
3764 otherwise "NumElements" is defaulted to be one. If a constant alignment is
3765 specified, the value result of the allocation is guaranteed to be aligned to
3766 at least that boundary. If not specified, or if zero, the target can choose
3767 to align the allocation on any convenient boundary compatible with the
3768 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3769
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3770<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3771
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3772<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]3773<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3774 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
3775 memory is automatically released when the function returns. The
3776 '<tt>alloca</tt>' instruction is commonly used to represent automatic
3777 variables that must have an address available. When the function returns
3778 (either with the <tt><a href="#i_ret">ret</a></tt>
3779 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
3780 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3781
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3782<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3783<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]3784 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3785 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3786 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3787 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3788</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3789
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3790</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]3791
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3792<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3793<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3794Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3795
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3796<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3797
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3798<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3799<pre>
3800 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3801 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3802</pre>
3803
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3804<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3805<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3806
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3807<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3808<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
3809 from which to load. The pointer must point to
3810 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
3811 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
3812 number or order of execution of this <tt>load</tt> with other
3813 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3814 instructions. </p>
3815
3816<p>The optional constant "align" argument specifies the alignment of the
3817 operation (that is, the alignment of the memory address). A value of 0 or an
3818 omitted "align" argument means that the operation has the preferential
3819 alignment for the target. It is the responsibility of the code emitter to
3820 ensure that the alignment information is correct. Overestimating the
3821 alignment results in an undefined behavior. Underestimating the alignment may
3822 produce less efficient code. An alignment of 1 is always safe.</p>
3823
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3824<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3825<p>The location of memory pointed to is loaded. If the value being loaded is of
3826 scalar type then the number of bytes read does not exceed the minimum number
3827 of bytes needed to hold all bits of the type. For example, loading an
3828 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
3829 <tt>i20</tt> with a size that is not an integral number of bytes, the result
3830 is undefined if the value was not originally written using a store of the
3831 same type.</p>
3832
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3833<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3834<pre>
3835 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
3836 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3837 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3838</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3839
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3840</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3841
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3842<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3843<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3844Instruction</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3845
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]3846<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3847
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3848<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3849<pre>
3850 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]3851 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]3852</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3853
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3854<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3855<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3856
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3857<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3858<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
3859 and an address at which to store it. The type of the
3860 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
3861 the <a href="#t_firstclass">first class</a> type of the
3862 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
3863 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
3864 or order of execution of this <tt>store</tt> with other
3865 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3866 instructions.</p>
3867
3868<p>The optional constant "align" argument specifies the alignment of the
3869 operation (that is, the alignment of the memory address). A value of 0 or an
3870 omitted "align" argument means that the operation has the preferential
3871 alignment for the target. It is the responsibility of the code emitter to
3872 ensure that the alignment information is correct. Overestimating the
3873 alignment results in an undefined behavior. Underestimating the alignment may
3874 produce less efficient code. An alignment of 1 is always safe.</p>
3875
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3876<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3877<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
3878 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
3879 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
3880 does not exceed the minimum number of bytes needed to hold all bits of the
3881 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
3882 writing a value of a type like <tt>i20</tt> with a size that is not an
3883 integral number of bytes, it is unspecified what happens to the extra bits
3884 that do not belong to the type, but they will typically be overwritten.</p>
3885
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3886<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3887<pre>
3888 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]3889 store i32 3, i32* %ptr <i>; yields {void}</i>
3890 %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]3891</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3892
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]3893</div>
3894
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]3895<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3896<div class="doc_subsubsection">
3897 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3898</div>
3899
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3900<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3901
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3902<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3903<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3904 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3905</pre>
3906
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3907<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3908<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
3909 subelement of an aggregate data structure. It performs address calculation
3910 only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3911
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3912<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3913<p>The first argument is always a pointer, and forms the basis of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3914 calculation. The remaining arguments are indices, that indicate which of the
3915 elements of the aggregate object are indexed. The interpretation of each
3916 index is dependent on the type being indexed into. The first index always
3917 indexes the pointer value given as the first argument, the second index
3918 indexes a value of the type pointed to (not necessarily the value directly
3919 pointed to, since the first index can be non-zero), etc. The first type
3920 indexed into must be a pointer value, subsequent types can be arrays, vectors
3921 and structs. Note that subsequent types being indexed into can never be
3922 pointers, since that would require loading the pointer before continuing
3923 calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3924
3925<p>The type of each index argument depends on the type it is indexing into.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3926 When indexing into a (packed) structure, only <tt>i32</tt> integer
3927 <b>constants</b> are allowed. When indexing into an array, pointer or
3928 vector, integers of any width are allowed (also non-constants).</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3929
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3930<p>For example, let's consider a C code fragment and how it gets compiled to
3931 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3932
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3933<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3934<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3935struct RT {
3936 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3937 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3938 char C;
3939};
3940struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3941 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3942 double Y;
3943 struct RT Z;
3944};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3945
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]3946int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3947 return &amp;s[1].Z.B[5][13];
3948}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3949</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3950</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3951
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3952<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3953
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3954<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3955<pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]3956%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3957%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3958
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]3959define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3960entry:
3961 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3962 ret i32* %reg
3963}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3964</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3965</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3966
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3967<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3968<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]3969 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
3970 }</tt>' type, a structure. The second index indexes into the third element
3971 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3972 i8 }</tt>' type, another structure. The third index indexes into the second
3973 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
3974 array. The two dimensions of the array are subscripted into, yielding an
3975 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
3976 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3977
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3978<p>Note that it is perfectly legal to index partially through a structure,
3979 returning a pointer to an inner element. Because of this, the LLVM code for
3980 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3981
3982<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]3983 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3984 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3985 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3986 %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]3987 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3988 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3989 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3990 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3991</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]3992
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3993<p>The getelementptr instruction is often confusing. For some more insight into
3994 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]3995
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3996<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]3997<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3998 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]3999 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4000 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4001 %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]4002 <i>; yields i8*:eptr</i>
4003 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]4004 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]4005 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4006</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4007
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4008</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4009
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4010<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4011<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4012</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4013
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4014<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4015
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4016<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4017 which all take a single operand and a type. They perform various bit
4018 conversions on the operand.</p>
4019
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4020</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4021
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4022<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4023<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4024 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4025</div>
4026<div class="doc_text">
4027
4028<h5>Syntax:</h5>
4029<pre>
4030 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4031</pre>
4032
4033<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4034<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4035 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4036
4037<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4038<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4039 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4040 size and type of the result, which must be
4041 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4042 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4043 allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4044
4045<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4046<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4047 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4048 source size must be larger than the destination size, <tt>trunc</tt> cannot
4049 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4050
4051<h5>Example:</h5>
4052<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4053 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4054 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4055 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4056</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4057
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4058</div>
4059
4060<!-- _______________________________________________________________________ -->
4061<div class="doc_subsubsection">
4062 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4063</div>
4064<div class="doc_text">
4065
4066<h5>Syntax:</h5>
4067<pre>
4068 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4069</pre>
4070
4071<h5>Overview:</h5>
4072<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4073 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4074
4075
4076<h5>Arguments:</h5>
4077<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]4078 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4079 also be of <a href="#t_integer">integer</a> type. The bit size of the
4080 <tt>value</tt> must be smaller than the bit size of the destination type,
4081 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4082
4083<h5>Semantics:</h5>
4084<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]4085 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4086
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]4087<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]4088
4089<h5>Example:</h5>
4090<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4091 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4092 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4093</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4094
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4095</div>
4096
4097<!-- _______________________________________________________________________ -->
4098<div class="doc_subsubsection">
4099 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4100</div>
4101<div class="doc_text">
4102
4103<h5>Syntax:</h5>
4104<pre>
4105 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4106</pre>
4107
4108<h5>Overview:</h5>
4109<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4110
4111<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4112<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
4113 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4114 also be of <a href="#t_integer">integer</a> type. The bit size of the
4115 <tt>value</tt> must be smaller than the bit size of the destination type,
4116 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4117
4118<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4119<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4120 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4121 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4122
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4123<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]4124
4125<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4126<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4127 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4128 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4129</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4130
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4131</div>
4132
4133<!-- _______________________________________________________________________ -->
4134<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4135 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4136</div>
4137
4138<div class="doc_text">
4139
4140<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4141<pre>
4142 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4143</pre>
4144
4145<h5>Overview:</h5>
4146<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4147 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4148
4149<h5>Arguments:</h5>
4150<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4151 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4152 to cast it to. The size of <tt>value</tt> must be larger than the size of
4153 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
4154 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4155
4156<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4157<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
4158 <a href="#t_floating">floating point</a> type to a smaller
4159 <a href="#t_floating">floating point</a> type. If the value cannot fit
4160 within the destination type, <tt>ty2</tt>, then the results are
4161 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4162
4163<h5>Example:</h5>
4164<pre>
4165 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4166 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4167</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4168
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4169</div>
4170
4171<!-- _______________________________________________________________________ -->
4172<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4173 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4174</div>
4175<div class="doc_text">
4176
4177<h5>Syntax:</h5>
4178<pre>
4179 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4180</pre>
4181
4182<h5>Overview:</h5>
4183<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]4184 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4185
4186<h5>Arguments:</h5>
4187<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4188 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4189 a <a href="#t_floating">floating point</a> type to cast it to. The source
4190 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4191
4192<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4193<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4194 <a href="#t_floating">floating point</a> type to a larger
4195 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4196 used to make a <i>no-op cast</i> because it always changes bits. Use
4197 <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]4198
4199<h5>Example:</h5>
4200<pre>
4201 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4202 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4203</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4204
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4205</div>
4206
4207<!-- _______________________________________________________________________ -->
4208<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]4209 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4210</div>
4211<div class="doc_text">
4212
4213<h5>Syntax:</h5>
4214<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4215 &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]4216</pre>
4217
4218<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4219<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4220 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4221
4222<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4223<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4224 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4225 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4226 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4227 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4228
4229<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4230<p>The '<tt>fptoui</tt>' instruction converts its
4231 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4232 towards zero) unsigned integer value. If the value cannot fit
4233 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4234
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4235<h5>Example:</h5>
4236<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4237 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4238 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4239 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4240</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4241
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4242</div>
4243
4244<!-- _______________________________________________________________________ -->
4245<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4246 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4247</div>
4248<div class="doc_text">
4249
4250<h5>Syntax:</h5>
4251<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4252 &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]4253</pre>
4254
4255<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4256<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4257 <a href="#t_floating">floating point</a> <tt>value</tt> to
4258 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4259
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4260<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4261<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4262 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4263 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4264 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4265 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4266
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4267<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4268<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4269 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4270 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4271 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4272
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4273<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4274<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4275 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4276 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4277 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4278</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4279
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4280</div>
4281
4282<!-- _______________________________________________________________________ -->
4283<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4284 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4285</div>
4286<div class="doc_text">
4287
4288<h5>Syntax:</h5>
4289<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4290 &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]4291</pre>
4292
4293<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4294<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4295 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4296
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4297<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4298<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]4299 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4300 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4301 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4302 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4303
4304<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4305<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4306 integer quantity and converts it to the corresponding floating point
4307 value. If the value cannot fit in the floating point value, the results are
4308 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4309
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4310<h5>Example:</h5>
4311<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4312 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4313 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4314</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4315
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4316</div>
4317
4318<!-- _______________________________________________________________________ -->
4319<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4320 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4321</div>
4322<div class="doc_text">
4323
4324<h5>Syntax:</h5>
4325<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4326 &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]4327</pre>
4328
4329<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4330<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4331 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4332
4333<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4334<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]4335 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4336 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4337 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4338 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4339
4340<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4341<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4342 quantity and converts it to the corresponding floating point value. If the
4343 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4344
4345<h5>Example:</h5>
4346<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4347 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4348 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4349</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4350
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4351</div>
4352
4353<!-- _______________________________________________________________________ -->
4354<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4355 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4356</div>
4357<div class="doc_text">
4358
4359<h5>Syntax:</h5>
4360<pre>
4361 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4362</pre>
4363
4364<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4365<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4366 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4367
4368<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4369<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4370 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4371 <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]4372
4373<h5>Semantics:</h5>
4374<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4375 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4376 truncating or zero extending that value to the size of the integer type. If
4377 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4378 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4379 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4380 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4381
4382<h5>Example:</h5>
4383<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4384 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4385 %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]4386</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4387
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4388</div>
4389
4390<!-- _______________________________________________________________________ -->
4391<div class="doc_subsubsection">
4392 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4393</div>
4394<div class="doc_text">
4395
4396<h5>Syntax:</h5>
4397<pre>
4398 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4399</pre>
4400
4401<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4402<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4403 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4404
4405<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]4406<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4407 value to cast, and a type to cast it to, which must be a
4408 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4409
4410<h5>Semantics:</h5>
4411<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4412 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4413 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4414 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4415 than the size of a pointer then a zero extension is done. If they are the
4416 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4417
4418<h5>Example:</h5>
4419<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4420 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4421 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4422 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4423</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4424
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]4425</div>
4426
4427<!-- _______________________________________________________________________ -->
4428<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4429 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4430</div>
4431<div class="doc_text">
4432
4433<h5>Syntax:</h5>
4434<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4435 &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]4436</pre>
4437
4438<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4439<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4440 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4441
4442<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4443<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4444 non-aggregate first class value, and a type to cast it to, which must also be
4445 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4446 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4447 identical. If the source type is a pointer, the destination type must also be
4448 a pointer. This instruction supports bitwise conversion of vectors to
4449 integers and to vectors of other types (as long as they have the same
4450 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4451
4452<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]4453<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4454 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4455 this conversion. The conversion is done as if the <tt>value</tt> had been
4456 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4457 be converted to other pointer types with this instruction. To convert
4458 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4459 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4460
4461<h5>Example:</h5>
4462<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4463 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4464 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4465 %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]4466</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4467
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4468</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4469
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4470<!-- ======================================================================= -->
4471<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4472
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4473<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4474
4475<p>The instructions in this category are the "miscellaneous" instructions, which
4476 defy better classification.</p>
4477
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4478</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4479
4480<!-- _______________________________________________________________________ -->
4481<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4482</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4483
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4484<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4485
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4486<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4487<pre>
4488 &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]4489</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4490
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4491<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4492<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4493 boolean values based on comparison of its two integer, integer vector, or
4494 pointer operands.</p>
4495
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4496<h5>Arguments:</h5>
4497<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4498 the condition code indicating the kind of comparison to perform. It is not a
4499 value, just a keyword. The possible condition code are:</p>
4500
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4501<ol>
4502 <li><tt>eq</tt>: equal</li>
4503 <li><tt>ne</tt>: not equal </li>
4504 <li><tt>ugt</tt>: unsigned greater than</li>
4505 <li><tt>uge</tt>: unsigned greater or equal</li>
4506 <li><tt>ult</tt>: unsigned less than</li>
4507 <li><tt>ule</tt>: unsigned less or equal</li>
4508 <li><tt>sgt</tt>: signed greater than</li>
4509 <li><tt>sge</tt>: signed greater or equal</li>
4510 <li><tt>slt</tt>: signed less than</li>
4511 <li><tt>sle</tt>: signed less or equal</li>
4512</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4513
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]4514<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4515 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4516 typed. They must also be identical types.</p>
4517
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4518<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4519<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4520 condition code given as <tt>cond</tt>. The comparison performed always yields
4521 either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt>
4522 result, as follows:</p>
4523
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4524<ol>
4525 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4526 <tt>false</tt> otherwise. No sign interpretation is necessary or
4527 performed.</li>
4528
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4529 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4530 <tt>false</tt> otherwise. No sign interpretation is necessary or
4531 performed.</li>
4532
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4533 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4534 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4535
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4536 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4537 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4538 to <tt>op2</tt>.</li>
4539
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4540 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4541 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4542
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4543 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4544 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4545
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4546 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4547 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4548
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4549 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4550 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4551 to <tt>op2</tt>.</li>
4552
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4553 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4554 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4555
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4556 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4557 <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]4558</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4559
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4560<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4561 values are compared as if they were integers.</p>
4562
4563<p>If the operands are integer vectors, then they are compared element by
4564 element. The result is an <tt>i1</tt> vector with the same number of elements
4565 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4566
4567<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4568<pre>
4569 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4570 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4571 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4572 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4573 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4574 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4575</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4576
4577<p>Note that the code generator does not yet support vector types with
4578 the <tt>icmp</tt> instruction.</p>
4579
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4580</div>
4581
4582<!-- _______________________________________________________________________ -->
4583<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4584</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4585
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4586<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4587
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4588<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4589<pre>
4590 &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]4591</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4592
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4593<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4594<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4595 values based on comparison of its operands.</p>
4596
4597<p>If the operands are floating point scalars, then the result type is a boolean
4598(<a href="#t_primitive"><tt>i1</tt></a>).</p>
4599
4600<p>If the operands are floating point vectors, then the result type is a vector
4601 of boolean with the same number of elements as the operands being
4602 compared.</p>
4603
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4604<h5>Arguments:</h5>
4605<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4606 the condition code indicating the kind of comparison to perform. It is not a
4607 value, just a keyword. The possible condition code are:</p>
4608
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4609<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4610 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4611 <li><tt>oeq</tt>: ordered and equal</li>
4612 <li><tt>ogt</tt>: ordered and greater than </li>
4613 <li><tt>oge</tt>: ordered and greater than or equal</li>
4614 <li><tt>olt</tt>: ordered and less than </li>
4615 <li><tt>ole</tt>: ordered and less than or equal</li>
4616 <li><tt>one</tt>: ordered and not equal</li>
4617 <li><tt>ord</tt>: ordered (no nans)</li>
4618 <li><tt>ueq</tt>: unordered or equal</li>
4619 <li><tt>ugt</tt>: unordered or greater than </li>
4620 <li><tt>uge</tt>: unordered or greater than or equal</li>
4621 <li><tt>ult</tt>: unordered or less than </li>
4622 <li><tt>ule</tt>: unordered or less than or equal</li>
4623 <li><tt>une</tt>: unordered or not equal</li>
4624 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4625 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4626</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4627
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4628<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4629 <i>unordered</i> means that either operand may be a QNAN.</p>
4630
4631<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
4632 a <a href="#t_floating">floating point</a> type or
4633 a <a href="#t_vector">vector</a> of floating point type. They must have
4634 identical types.</p>
4635
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4636<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4637<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4638 according to the condition code given as <tt>cond</tt>. If the operands are
4639 vectors, then the vectors are compared element by element. Each comparison
4640 performed always yields an <a href="#t_primitive">i1</a> result, as
4641 follows:</p>
4642
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4643<ol>
4644 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4645
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4646 <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]4647 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4648
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4649 <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]4650 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
4651
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4652 <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]4653 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4654
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4655 <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]4656 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4657
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4658 <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]4659 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4660
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4661 <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]4662 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4663
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4664 <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]4665
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4666 <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]4667 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4668
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4669 <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]4670 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4671
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4672 <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]4673 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4674
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4675 <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]4676 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4677
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4678 <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]4679 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4680
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4681 <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]4682 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4683
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]4684 <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]4685
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4686 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4687</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4688
4689<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4690<pre>
4691 &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]4692 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4693 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4694 &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]4695</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4696
4697<p>Note that the code generator does not yet support vector types with
4698 the <tt>fcmp</tt> instruction.</p>
4699
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]4700</div>
4701
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4702<!-- _______________________________________________________________________ -->
Nate Begemanac80ade2008-05-12 19:01:56 +0000[diff] [blame]4703<div class="doc_subsubsection">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4704 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4705</div>
4706
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4707<div class="doc_text">
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4708
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4709<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4710<pre>
4711 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
4712</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4713
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4714<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4715<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
4716 SSA graph representing the function.</p>
4717
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4718<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4719<p>The type of the incoming values is specified with the first type field. After
4720 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
4721 one pair for each predecessor basic block of the current block. Only values
4722 of <a href="#t_firstclass">first class</a> type may be used as the value
4723 arguments to the PHI node. Only labels may be used as the label
4724 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4725
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4726<p>There must be no non-phi instructions between the start of a basic block and
4727 the PHI instructions: i.e. PHI instructions must be first in a basic
4728 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4729
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4730<p>For the purposes of the SSA form, the use of each incoming value is deemed to
4731 occur on the edge from the corresponding predecessor block to the current
4732 block (but after any definition of an '<tt>invoke</tt>' instruction's return
4733 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]4734
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4735<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4736<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4737 specified by the pair corresponding to the predecessor basic block that
4738 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4739
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4740<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4741<pre>
4742Loop: ; Infinite loop that counts from 0 on up...
4743 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4744 %nextindvar = add i32 %indvar, 1
4745 br label %Loop
4746</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4747
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4748</div>
4749
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4750<!-- _______________________________________________________________________ -->
4751<div class="doc_subsubsection">
4752 <a name="i_select">'<tt>select</tt>' Instruction</a>
4753</div>
4754
4755<div class="doc_text">
4756
4757<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4758<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]4759 &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>
4760
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4761 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4762</pre>
4763
4764<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4765<p>The '<tt>select</tt>' instruction is used to choose one value based on a
4766 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4767
4768
4769<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4770<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
4771 values indicating the condition, and two values of the
4772 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
4773 vectors and the condition is a scalar, then entire vectors are selected, not
4774 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4775
4776<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4777<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
4778 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4779
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4780<p>If the condition is a vector of i1, then the value arguments must be vectors
4781 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4782
4783<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4784<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4785 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4786</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]4787
4788<p>Note that the code generator does not yet support conditions
4789 with vector type.</p>
4790
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4791</div>
4792
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]4793<!-- _______________________________________________________________________ -->
4794<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4795 <a name="i_call">'<tt>call</tt>' Instruction</a>
4796</div>
4797
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4798<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4799
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4800<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4801<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]4802 &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]4803</pre>
4804
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4805<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4806<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4807
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4808<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4809<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4810
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4811<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4812 <li>The optional "tail" marker indicates whether the callee function accesses
4813 any allocas or varargs in the caller. If the "tail" marker is present,
4814 the function call is eligible for tail call optimization. Note that calls
4815 may be marked "tail" even if they do not occur before
4816 a <a href="#i_ret"><tt>ret</tt></a> instruction.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4817
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4818 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
4819 convention</a> the call should use. If none is specified, the call
4820 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4821
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4822 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4823 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
4824 '<tt>inreg</tt>' attributes are valid here.</li>
4825
4826 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
4827 type of the return value. Functions that return no value are marked
4828 <tt><a href="#t_void">void</a></tt>.</li>
4829
4830 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
4831 being invoked. The argument types must match the types implied by this
4832 signature. This type can be omitted if the function is not varargs and if
4833 the function type does not return a pointer to a function.</li>
4834
4835 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4836 be invoked. In most cases, this is a direct function invocation, but
4837 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
4838 to function value.</li>
4839
4840 <li>'<tt>function args</tt>': argument list whose types match the function
4841 signature argument types. All arguments must be of
4842 <a href="#t_firstclass">first class</a> type. If the function signature
4843 indicates the function accepts a variable number of arguments, the extra
4844 arguments can be specified.</li>
4845
4846 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
4847 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4848 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4849</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4850
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4851<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4852<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
4853 a specified function, with its incoming arguments bound to the specified
4854 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
4855 function, control flow continues with the instruction after the function
4856 call, and the return value of the function is bound to the result
4857 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4858
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4859<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4860<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]4861 %retval = call i32 @test(i32 %argc)
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]4862 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4863 %X = tail call i32 @foo() <i>; yields i32</i>
4864 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4865 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]4866
4867 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]4868 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]4869 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4870 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]4871 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]4872 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]4873</pre>
4874
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4875</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4876
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4877<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4878<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]4879 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4880</div>
4881
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4882<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4883
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4884<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4885<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4886 &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]4887</pre>
4888
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4889<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]4890<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4891 the "variable argument" area of a function call. It is used to implement the
4892 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4893
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4894<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4895<p>This instruction takes a <tt>va_list*</tt> value and the type of the
4896 argument. It returns a value of the specified argument type and increments
4897 the <tt>va_list</tt> to point to the next argument. The actual type
4898 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4899
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4900<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4901<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
4902 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
4903 to the next argument. For more information, see the variable argument
4904 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4905
4906<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]4907 take a variable number of arguments, for example, the <tt>vfprintf</tt>
4908 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4909
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4910<p><tt>va_arg</tt> is an LLVM instruction instead of
4911 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
4912 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4913
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]4914<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]4915<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4916
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4917<p>Note that the code generator does not yet fully support va_arg on many
4918 targets. Also, it does not currently support va_arg with aggregate types on
4919 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]4920
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4921</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4922
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4923<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4924<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4925<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4926
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4927<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4928
4929<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4930 well known names and semantics and are required to follow certain
4931 restrictions. Overall, these intrinsics represent an extension mechanism for
4932 the LLVM language that does not require changing all of the transformations
4933 in LLVM when adding to the language (or the bitcode reader/writer, the
4934 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4935
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4936<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4937 prefix is reserved in LLVM for intrinsic names; thus, function names may not
4938 begin with this prefix. Intrinsic functions must always be external
4939 functions: you cannot define the body of intrinsic functions. Intrinsic
4940 functions may only be used in call or invoke instructions: it is illegal to
4941 take the address of an intrinsic function. Additionally, because intrinsic
4942 functions are part of the LLVM language, it is required if any are added that
4943 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4944
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4945<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
4946 family of functions that perform the same operation but on different data
4947 types. Because LLVM can represent over 8 million different integer types,
4948 overloading is used commonly to allow an intrinsic function to operate on any
4949 integer type. One or more of the argument types or the result type can be
4950 overloaded to accept any integer type. Argument types may also be defined as
4951 exactly matching a previous argument's type or the result type. This allows
4952 an intrinsic function which accepts multiple arguments, but needs all of them
4953 to be of the same type, to only be overloaded with respect to a single
4954 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4955
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4956<p>Overloaded intrinsics will have the names of its overloaded argument types
4957 encoded into its function name, each preceded by a period. Only those types
4958 which are overloaded result in a name suffix. Arguments whose type is matched
4959 against another type do not. For example, the <tt>llvm.ctpop</tt> function
4960 can take an integer of any width and returns an integer of exactly the same
4961 integer width. This leads to a family of functions such as
4962 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
4963 %val)</tt>. Only one type, the return type, is overloaded, and only one type
4964 suffix is required. Because the argument's type is matched against the return
4965 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4966
4967<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4968 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4969
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4970</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4971
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]4972<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4973<div class="doc_subsection">
4974 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4975</div>
4976
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4977<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4978
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4979<p>Variable argument support is defined in LLVM with
4980 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
4981 intrinsic functions. These functions are related to the similarly named
4982 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4983
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4984<p>All of these functions operate on arguments that use a target-specific value
4985 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
4986 not define what this type is, so all transformations should be prepared to
4987 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4988
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]4989<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]4990 instruction and the variable argument handling intrinsic functions are
4991 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4992
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4993<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4994<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4995define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4996 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]4997 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]4998 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]4999 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5000
5001 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5002 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5003
5004 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5005 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5006 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5007 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5008 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5009
5010 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5011 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5012 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5013}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5014
5015declare void @llvm.va_start(i8*)
5016declare void @llvm.va_copy(i8*, i8*)
5017declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5018</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5019</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5020
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]5021</div>
5022
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5023<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5024<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5025 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5026</div>
5027
5028
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5029<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5030
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5031<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5032<pre>
5033 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5034</pre>
5035
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5036<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5037<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5038 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]5039
5040<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5041<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]5042
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5043<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5044<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]5045 macro available in C. In a target-dependent way, it initializes
5046 the <tt>va_list</tt> element to which the argument points, so that the next
5047 call to <tt>va_arg</tt> will produce the first variable argument passed to
5048 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5049 need to know the last argument of the function as the compiler can figure
5050 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5051
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5052</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5053
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5054<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5055<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5056 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5057</div>
5058
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5059<div class="doc_text">
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5060
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5061<h5>Syntax:</h5>
5062<pre>
5063 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5064</pre>
5065
5066<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5067<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5068 which has been initialized previously
5069 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5070 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5071
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5072<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5073<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]5074
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5075<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5076<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]5077 macro available in C. In a target-dependent way, it destroys
5078 the <tt>va_list</tt> element to which the argument points. Calls
5079 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5080 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5081 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5082
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5083</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5084
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5085<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5086<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5087 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5088</div>
5089
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5090<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5091
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5092<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5093<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5094 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5095</pre>
5096
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5097<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5098<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5099 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5100
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5101<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5102<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]5103 The second argument is a pointer to a <tt>va_list</tt> element to copy
5104 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5105
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5106<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5107<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]5108 macro available in C. In a target-dependent way, it copies the
5109 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5110 element. This intrinsic is necessary because
5111 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5112 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5113
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5114</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5115
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5116<!-- ======================================================================= -->
5117<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5118 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5119</div>
5120
5121<div class="doc_text">
5122
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5123<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5124Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5125intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5126roots on the stack</a>, as well as garbage collector implementations that
5127require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5128barriers. Front-ends for type-safe garbage collected languages should generate
5129these intrinsics to make use of the LLVM garbage collectors. For more details,
5130see <a href="GarbageCollection.html">Accurate Garbage Collection with
5131LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5132
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5133<p>The garbage collection intrinsics only operate on objects in the generic
5134 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5135
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5136</div>
5137
5138<!-- _______________________________________________________________________ -->
5139<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5140 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5141</div>
5142
5143<div class="doc_text">
5144
5145<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5146<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5147 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5148</pre>
5149
5150<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]5151<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]5152 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5153
5154<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5155<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5156 root pointer. The second pointer (which must be either a constant or a
5157 global value address) contains the meta-data to be associated with the
5158 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5159
5160<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]5161<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]5162 location. At compile-time, the code generator generates information to allow
5163 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5164 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5165 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5166
5167</div>
5168
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5169<!-- _______________________________________________________________________ -->
5170<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5171 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5172</div>
5173
5174<div class="doc_text">
5175
5176<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5177<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5178 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5179</pre>
5180
5181<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5182<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5183 locations, allowing garbage collector implementations that require read
5184 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5185
5186<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5187<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]5188 allocated from the garbage collector. The first object is a pointer to the
5189 start of the referenced object, if needed by the language runtime (otherwise
5190 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5191
5192<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5193<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5194 instruction, but may be replaced with substantially more complex code by the
5195 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5196 may only be used in a function which <a href="#gc">specifies a GC
5197 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5198
5199</div>
5200
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5201<!-- _______________________________________________________________________ -->
5202<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5203 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5204</div>
5205
5206<div class="doc_text">
5207
5208<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5209<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5210 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5211</pre>
5212
5213<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5214<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5215 locations, allowing garbage collector implementations that require write
5216 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5217
5218<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5219<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]5220 object to store it to, and the third is the address of the field of Obj to
5221 store to. If the runtime does not require a pointer to the object, Obj may
5222 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5223
5224<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5225<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5226 instruction, but may be replaced with substantially more complex code by the
5227 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5228 may only be used in a function which <a href="#gc">specifies a GC
5229 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5230
5231</div>
5232
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5233<!-- ======================================================================= -->
5234<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5235 <a name="int_codegen">Code Generator Intrinsics</a>
5236</div>
5237
5238<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5239
5240<p>These intrinsics are provided by LLVM to expose special features that may
5241 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5242
5243</div>
5244
5245<!-- _______________________________________________________________________ -->
5246<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5247 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5248</div>
5249
5250<div class="doc_text">
5251
5252<h5>Syntax:</h5>
5253<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5254 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5255</pre>
5256
5257<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5258<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5259 target-specific value indicating the return address of the current function
5260 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5261
5262<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5263<p>The argument to this intrinsic indicates which function to return the address
5264 for. Zero indicates the calling function, one indicates its caller, etc.
5265 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5266
5267<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5268<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5269 indicating the return address of the specified call frame, or zero if it
5270 cannot be identified. The value returned by this intrinsic is likely to be
5271 incorrect or 0 for arguments other than zero, so it should only be used for
5272 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5273
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5274<p>Note that calling this intrinsic does not prevent function inlining or other
5275 aggressive transformations, so the value returned may not be that of the
5276 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5277
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5278</div>
5279
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5280<!-- _______________________________________________________________________ -->
5281<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5282 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5283</div>
5284
5285<div class="doc_text">
5286
5287<h5>Syntax:</h5>
5288<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5289 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5290</pre>
5291
5292<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5293<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5294 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5295
5296<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5297<p>The argument to this intrinsic indicates which function to return the frame
5298 pointer for. Zero indicates the calling function, one indicates its caller,
5299 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5300
5301<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5302<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5303 indicating the frame address of the specified call frame, or zero if it
5304 cannot be identified. The value returned by this intrinsic is likely to be
5305 incorrect or 0 for arguments other than zero, so it should only be used for
5306 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5307
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5308<p>Note that calling this intrinsic does not prevent function inlining or other
5309 aggressive transformations, so the value returned may not be that of the
5310 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5311
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5312</div>
5313
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5314<!-- _______________________________________________________________________ -->
5315<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5316 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5317</div>
5318
5319<div class="doc_text">
5320
5321<h5>Syntax:</h5>
5322<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5323 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5324</pre>
5325
5326<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5327<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5328 of the function stack, for use
5329 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5330 useful for implementing language features like scoped automatic variable
5331 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5332
5333<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5334<p>This intrinsic returns a opaque pointer value that can be passed
5335 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5336 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5337 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5338 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5339 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5340 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5341
5342</div>
5343
5344<!-- _______________________________________________________________________ -->
5345<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5346 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5347</div>
5348
5349<div class="doc_text">
5350
5351<h5>Syntax:</h5>
5352<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5353 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5354</pre>
5355
5356<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5357<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5358 the function stack to the state it was in when the
5359 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5360 executed. This is useful for implementing language features like scoped
5361 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5362
5363<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5364<p>See the description
5365 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5366
5367</div>
5368
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]5369<!-- _______________________________________________________________________ -->
5370<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5371 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5372</div>
5373
5374<div class="doc_text">
5375
5376<h5>Syntax:</h5>
5377<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5378 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]5379</pre>
5380
5381<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5382<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5383 insert a prefetch instruction if supported; otherwise, it is a noop.
5384 Prefetches have no effect on the behavior of the program but can change its
5385 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5386
5387<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5388<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5389 specifier determining if the fetch should be for a read (0) or write (1),
5390 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5391 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5392 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5393
5394<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5395<p>This intrinsic does not modify the behavior of the program. In particular,
5396 prefetches cannot trap and do not produce a value. On targets that support
5397 this intrinsic, the prefetch can provide hints to the processor cache for
5398 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]5399
5400</div>
5401
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5402<!-- _______________________________________________________________________ -->
5403<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5404 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5405</div>
5406
5407<div class="doc_text">
5408
5409<h5>Syntax:</h5>
5410<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5411 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5412</pre>
5413
5414<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5415<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5416 Counter (PC) in a region of code to simulators and other tools. The method
5417 is target specific, but it is expected that the marker will use exported
5418 symbols to transmit the PC of the marker. The marker makes no guarantees
5419 that it will remain with any specific instruction after optimizations. It is
5420 possible that the presence of a marker will inhibit optimizations. The
5421 intended use is to be inserted after optimizations to allow correlations of
5422 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5423
5424<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5425<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5426
5427<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5428<p>This intrinsic does not modify the behavior of the program. Backends that do
5429 not support this intrinisic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]5430
5431</div>
5432
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5433<!-- _______________________________________________________________________ -->
5434<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5435 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5436</div>
5437
5438<div class="doc_text">
5439
5440<h5>Syntax:</h5>
5441<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5442 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5443</pre>
5444
5445<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5446<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5447 counter register (or similar low latency, high accuracy clocks) on those
5448 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5449 should map to RPCC. As the backing counters overflow quickly (on the order
5450 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5451
5452<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5453<p>When directly supported, reading the cycle counter should not modify any
5454 memory. Implementations are allowed to either return a application specific
5455 value or a system wide value. On backends without support, this is lowered
5456 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]5457
5458</div>
5459
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5460<!-- ======================================================================= -->
5461<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5462 <a name="int_libc">Standard C Library Intrinsics</a>
5463</div>
5464
5465<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5466
5467<p>LLVM provides intrinsics for a few important standard C library functions.
5468 These intrinsics allow source-language front-ends to pass information about
5469 the alignment of the pointer arguments to the code generator, providing
5470 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5471
5472</div>
5473
5474<!-- _______________________________________________________________________ -->
5475<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5476 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5477</div>
5478
5479<div class="doc_text">
5480
5481<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5482<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
5483 integer bit width. Not all targets support all bit widths however.</p>
5484
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5485<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5486 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5487 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5488 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5489 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5490 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5491 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5492 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5493 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5494</pre>
5495
5496<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5497<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5498 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5499
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5500<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5501 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5502
5503<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5504<p>The first argument is a pointer to the destination, the second is a pointer
5505 to the source. The third argument is an integer argument specifying the
5506 number of bytes to copy, and the fourth argument is the alignment of the
5507 source and destination locations.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5508
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5509<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5510 then the caller guarantees that both the source and destination pointers are
5511 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5512
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5513<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5514<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5515 source location to the destination location, which are not allowed to
5516 overlap. It copies "len" bytes of memory over. If the argument is known to
5517 be aligned to some boundary, this can be specified as the fourth argument,
5518 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5519
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5520</div>
5521
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5522<!-- _______________________________________________________________________ -->
5523<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5524 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5525</div>
5526
5527<div class="doc_text">
5528
5529<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5530<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]5531 width. Not all targets support all bit widths however.</p>
5532
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5533<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5534 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5535 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5536 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5537 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5538 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5539 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5540 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5541 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5542</pre>
5543
5544<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5545<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5546 source location to the destination location. It is similar to the
5547 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5548 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5549
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5550<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5551 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5552
5553<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5554<p>The first argument is a pointer to the destination, the second is a pointer
5555 to the source. The third argument is an integer argument specifying the
5556 number of bytes to copy, and the fourth argument is the alignment of the
5557 source and destination locations.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5558
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5559<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5560 then the caller guarantees that the source and destination pointers are
5561 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]5562
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5563<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5564<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5565 source location to the destination location, which may overlap. It copies
5566 "len" bytes of memory over. If the argument is known to be aligned to some
5567 boundary, this can be specified as the fourth argument, otherwise it should
5568 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5569
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]5570</div>
5571
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5572<!-- _______________________________________________________________________ -->
5573<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5574 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5575</div>
5576
5577<div class="doc_text">
5578
5579<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5580<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]5581 width. Not all targets support all bit widths however.</p>
5582
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5583<pre>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5584 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5585 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]5586 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5587 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5588 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5589 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5590 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5591 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5592</pre>
5593
5594<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5595<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
5596 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5597
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5598<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
5599 intrinsic does not return a value, and takes an extra alignment argument.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5600
5601<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5602<p>The first argument is a pointer to the destination to fill, the second is the
5603 byte value to fill it with, the third argument is an integer argument
5604 specifying the number of bytes to fill, and the fourth argument is the known
5605 alignment of destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5606
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5607<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5608 then the caller guarantees that the destination pointer is aligned to that
5609 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5610
5611<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5612<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
5613 at the destination location. If the argument is known to be aligned to some
5614 boundary, this can be specified as the fourth argument, otherwise it should
5615 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5616
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5617</div>
5618
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5619<!-- _______________________________________________________________________ -->
5620<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5621 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5622</div>
5623
5624<div class="doc_text">
5625
5626<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5627<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
5628 floating point or vector of floating point type. Not all targets support all
5629 types however.</p>
5630
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5631<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5632 declare float @llvm.sqrt.f32(float %Val)
5633 declare double @llvm.sqrt.f64(double %Val)
5634 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5635 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5636 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5637</pre>
5638
5639<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5640<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
5641 returning the same value as the libm '<tt>sqrt</tt>' functions would.
5642 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
5643 behavior for negative numbers other than -0.0 (which allows for better
5644 optimization, because there is no need to worry about errno being
5645 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]5646
5647<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5648<p>The argument and return value are floating point numbers of the same
5649 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5650
5651<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5652<p>This function returns the sqrt of the specified operand if it is a
5653 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5654
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]5655</div>
5656
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5657<!-- _______________________________________________________________________ -->
5658<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5659 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5660</div>
5661
5662<div class="doc_text">
5663
5664<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5665<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
5666 floating point or vector of floating point type. Not all targets support all
5667 types however.</p>
5668
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5669<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]5670 declare float @llvm.powi.f32(float %Val, i32 %power)
5671 declare double @llvm.powi.f64(double %Val, i32 %power)
5672 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5673 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5674 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5675</pre>
5676
5677<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5678<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5679 specified (positive or negative) power. The order of evaluation of
5680 multiplications is not defined. When a vector of floating point type is
5681 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5682
5683<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5684<p>The second argument is an integer power, and the first is a value to raise to
5685 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5686
5687<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5688<p>This function returns the first value raised to the second power with an
5689 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5690
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]5691</div>
5692
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5693<!-- _______________________________________________________________________ -->
5694<div class="doc_subsubsection">
5695 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5696</div>
5697
5698<div class="doc_text">
5699
5700<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5701<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5702 floating point or vector of floating point type. Not all targets support all
5703 types however.</p>
5704
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5705<pre>
5706 declare float @llvm.sin.f32(float %Val)
5707 declare double @llvm.sin.f64(double %Val)
5708 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5709 declare fp128 @llvm.sin.f128(fp128 %Val)
5710 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5711</pre>
5712
5713<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5714<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5715
5716<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5717<p>The argument and return value are floating point numbers of the same
5718 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5719
5720<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5721<p>This function returns the sine of the specified operand, returning the same
5722 values as the libm <tt>sin</tt> functions would, and handles error conditions
5723 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5724
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5725</div>
5726
5727<!-- _______________________________________________________________________ -->
5728<div class="doc_subsubsection">
5729 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5730</div>
5731
5732<div class="doc_text">
5733
5734<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5735<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5736 floating point or vector of floating point type. Not all targets support all
5737 types however.</p>
5738
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5739<pre>
5740 declare float @llvm.cos.f32(float %Val)
5741 declare double @llvm.cos.f64(double %Val)
5742 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5743 declare fp128 @llvm.cos.f128(fp128 %Val)
5744 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5745</pre>
5746
5747<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5748<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5749
5750<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5751<p>The argument and return value are floating point numbers of the same
5752 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5753
5754<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5755<p>This function returns the cosine of the specified operand, returning the same
5756 values as the libm <tt>cos</tt> functions would, and handles error conditions
5757 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5758
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5759</div>
5760
5761<!-- _______________________________________________________________________ -->
5762<div class="doc_subsubsection">
5763 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5764</div>
5765
5766<div class="doc_text">
5767
5768<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5769<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5770 floating point or vector of floating point type. Not all targets support all
5771 types however.</p>
5772
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5773<pre>
5774 declare float @llvm.pow.f32(float %Val, float %Power)
5775 declare double @llvm.pow.f64(double %Val, double %Power)
5776 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5777 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5778 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5779</pre>
5780
5781<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5782<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5783 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5784
5785<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5786<p>The second argument is a floating point power, and the first is a value to
5787 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5788
5789<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5790<p>This function returns the first value raised to the second power, returning
5791 the same values as the libm <tt>pow</tt> functions would, and handles error
5792 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5793
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]5794</div>
5795
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5796<!-- ======================================================================= -->
5797<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5798 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5799</div>
5800
5801<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5802
5803<p>LLVM provides intrinsics for a few important bit manipulation operations.
5804 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5805
5806</div>
5807
5808<!-- _______________________________________________________________________ -->
5809<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5810 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5811</div>
5812
5813<div class="doc_text">
5814
5815<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5816<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5817 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
5818
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5819<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5820 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5821 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5822 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5823</pre>
5824
5825<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5826<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
5827 values with an even number of bytes (positive multiple of 16 bits). These
5828 are useful for performing operations on data that is not in the target's
5829 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5830
5831<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5832<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
5833 and low byte of the input i16 swapped. Similarly,
5834 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
5835 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
5836 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
5837 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
5838 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
5839 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]5840
5841</div>
5842
5843<!-- _______________________________________________________________________ -->
5844<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]5845 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5846</div>
5847
5848<div class="doc_text">
5849
5850<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5851<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]5852 width. Not all targets support all bit widths however.</p>
5853
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5854<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5855 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5856 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5857 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5858 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5859 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5860</pre>
5861
5862<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5863<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
5864 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5865
5866<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5867<p>The only argument is the value to be counted. The argument may be of any
5868 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5869
5870<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5871<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]5872
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5873</div>
5874
5875<!-- _______________________________________________________________________ -->
5876<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5877 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5878</div>
5879
5880<div class="doc_text">
5881
5882<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5883<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
5884 integer bit width. Not all targets support all bit widths however.</p>
5885
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5886<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5887 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5888 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5889 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5890 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5891 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5892</pre>
5893
5894<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5895<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5896 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5897
5898<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5899<p>The only argument is the value to be counted. The argument may be of any
5900 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5901
5902<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5903<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
5904 zeros in a variable. If the src == 0 then the result is the size in bits of
5905 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5906
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]5907</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]5908
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5909<!-- _______________________________________________________________________ -->
5910<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]5911 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5912</div>
5913
5914<div class="doc_text">
5915
5916<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5917<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
5918 integer bit width. Not all targets support all bit widths however.</p>
5919
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5920<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5921 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5922 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5923 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]5924 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5925 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5926</pre>
5927
5928<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5929<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5930 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5931
5932<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5933<p>The only argument is the value to be counted. The argument may be of any
5934 integer type. The return type must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5935
5936<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5937<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
5938 zeros in a variable. If the src == 0 then the result is the size in bits of
5939 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5940
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]5941</div>
5942
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5943<!-- ======================================================================= -->
5944<div class="doc_subsection">
5945 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
5946</div>
5947
5948<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5949
5950<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5951
5952</div>
5953
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5954<!-- _______________________________________________________________________ -->
5955<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]5956 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5957</div>
5958
5959<div class="doc_text">
5960
5961<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5962<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]5963 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5964
5965<pre>
5966 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
5967 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5968 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
5969</pre>
5970
5971<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5972<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5973 a signed addition of the two arguments, and indicate whether an overflow
5974 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5975
5976<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5977<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]5978 be of integer types of any bit width, but they must have the same bit
5979 width. The second element of the result structure must be of
5980 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
5981 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5982
5983<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5984<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5985 a signed addition of the two variables. They return a structure &mdash; the
5986 first element of which is the signed summation, and the second element of
5987 which is a bit specifying if the signed summation resulted in an
5988 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]5989
5990<h5>Examples:</h5>
5991<pre>
5992 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5993 %sum = extractvalue {i32, i1} %res, 0
5994 %obit = extractvalue {i32, i1} %res, 1
5995 br i1 %obit, label %overflow, label %normal
5996</pre>
5997
5998</div>
5999
6000<!-- _______________________________________________________________________ -->
6001<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6002 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6003</div>
6004
6005<div class="doc_text">
6006
6007<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6008<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]6009 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6010
6011<pre>
6012 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6013 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6014 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6015</pre>
6016
6017<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6018<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6019 an unsigned addition of the two arguments, and indicate whether a carry
6020 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6021
6022<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6023<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]6024 be of integer types of any bit width, but they must have the same bit
6025 width. The second element of the result structure must be of
6026 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6027 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6028
6029<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6030<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6031 an unsigned addition of the two arguments. They return a structure &mdash;
6032 the first element of which is the sum, and the second element of which is a
6033 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6034
6035<h5>Examples:</h5>
6036<pre>
6037 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6038 %sum = extractvalue {i32, i1} %res, 0
6039 %obit = extractvalue {i32, i1} %res, 1
6040 br i1 %obit, label %carry, label %normal
6041</pre>
6042
6043</div>
6044
6045<!-- _______________________________________________________________________ -->
6046<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6047 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6048</div>
6049
6050<div class="doc_text">
6051
6052<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6053<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]6054 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6055
6056<pre>
6057 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6058 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6059 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6060</pre>
6061
6062<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6063<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6064 a signed subtraction of the two arguments, and indicate whether an overflow
6065 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6066
6067<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6068<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]6069 be of integer types of any bit width, but they must have the same bit
6070 width. The second element of the result structure must be of
6071 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6072 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6073
6074<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6075<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6076 a signed subtraction of the two arguments. They return a structure &mdash;
6077 the first element of which is the subtraction, and the second element of
6078 which is a bit specifying if the signed subtraction resulted in an
6079 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6080
6081<h5>Examples:</h5>
6082<pre>
6083 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6084 %sum = extractvalue {i32, i1} %res, 0
6085 %obit = extractvalue {i32, i1} %res, 1
6086 br i1 %obit, label %overflow, label %normal
6087</pre>
6088
6089</div>
6090
6091<!-- _______________________________________________________________________ -->
6092<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6093 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6094</div>
6095
6096<div class="doc_text">
6097
6098<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6099<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]6100 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6101
6102<pre>
6103 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6104 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6105 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6106</pre>
6107
6108<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6109<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6110 an unsigned subtraction of the two arguments, and indicate whether an
6111 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6112
6113<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6114<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]6115 be of integer types of any bit width, but they must have the same bit
6116 width. The second element of the result structure must be of
6117 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6118 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6119
6120<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6121<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6122 an unsigned subtraction of the two arguments. They return a structure &mdash;
6123 the first element of which is the subtraction, and the second element of
6124 which is a bit specifying if the unsigned subtraction resulted in an
6125 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6126
6127<h5>Examples:</h5>
6128<pre>
6129 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6130 %sum = extractvalue {i32, i1} %res, 0
6131 %obit = extractvalue {i32, i1} %res, 1
6132 br i1 %obit, label %overflow, label %normal
6133</pre>
6134
6135</div>
6136
6137<!-- _______________________________________________________________________ -->
6138<div class="doc_subsubsection">
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6139 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6140</div>
6141
6142<div class="doc_text">
6143
6144<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6145<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]6146 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6147
6148<pre>
6149 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6150 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6151 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6152</pre>
6153
6154<h5>Overview:</h5>
6155
6156<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6157 a signed multiplication of the two arguments, and indicate whether an
6158 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6159
6160<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6161<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]6162 be of integer types of any bit width, but they must have the same bit
6163 width. The second element of the result structure must be of
6164 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6165 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6166
6167<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6168<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6169 a signed multiplication of the two arguments. They return a structure &mdash;
6170 the first element of which is the multiplication, and the second element of
6171 which is a bit specifying if the signed multiplication resulted in an
6172 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6173
6174<h5>Examples:</h5>
6175<pre>
6176 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6177 %sum = extractvalue {i32, i1} %res, 0
6178 %obit = extractvalue {i32, i1} %res, 1
6179 br i1 %obit, label %overflow, label %normal
6180</pre>
6181
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6182</div>
6183
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6184<!-- _______________________________________________________________________ -->
6185<div class="doc_subsubsection">
6186 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6187</div>
6188
6189<div class="doc_text">
6190
6191<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6192<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]6193 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6194
6195<pre>
6196 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6197 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6198 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6199</pre>
6200
6201<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6202<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6203 a unsigned multiplication of the two arguments, and indicate whether an
6204 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6205
6206<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6207<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]6208 be of integer types of any bit width, but they must have the same bit
6209 width. The second element of the result structure must be of
6210 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6211 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6212
6213<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6214<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6215 an unsigned multiplication of the two arguments. They return a structure
6216 &mdash; the first element of which is the multiplication, and the second
6217 element of which is a bit specifying if the unsigned multiplication resulted
6218 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6219
6220<h5>Examples:</h5>
6221<pre>
6222 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6223 %sum = extractvalue {i32, i1} %res, 0
6224 %obit = extractvalue {i32, i1} %res, 1
6225 br i1 %obit, label %overflow, label %normal
6226</pre>
6227
6228</div>
6229
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6230<!-- ======================================================================= -->
6231<div class="doc_subsection">
6232 <a name="int_debugger">Debugger Intrinsics</a>
6233</div>
6234
6235<div class="doc_text">
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6236
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6237<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6238 prefix), are described in
6239 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6240 Level Debugging</a> document.</p>
6241
6242</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6243
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6244<!-- ======================================================================= -->
6245<div class="doc_subsection">
6246 <a name="int_eh">Exception Handling Intrinsics</a>
6247</div>
6248
6249<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6250
6251<p>The LLVM exception handling intrinsics (which all start with
6252 <tt>llvm.eh.</tt> prefix), are described in
6253 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6254 Handling</a> document.</p>
6255
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6256</div>
6257
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6258<!-- ======================================================================= -->
6259<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6260 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6261</div>
6262
6263<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6264
6265<p>This intrinsic makes it possible to excise one parameter, marked with
6266 the <tt>nest</tt> attribute, from a function. The result is a callable
6267 function pointer lacking the nest parameter - the caller does not need to
6268 provide a value for it. Instead, the value to use is stored in advance in a
6269 "trampoline", a block of memory usually allocated on the stack, which also
6270 contains code to splice the nest value into the argument list. This is used
6271 to implement the GCC nested function address extension.</p>
6272
6273<p>For example, if the function is
6274 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6275 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6276 follows:</p>
6277
6278<div class="doc_code">
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6279<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]6280 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6281 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6282 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6283 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6284</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6285</div>
6286
6287<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6288 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6289
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6290</div>
6291
6292<!-- _______________________________________________________________________ -->
6293<div class="doc_subsubsection">
6294 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6295</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6296
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6297<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6298
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6299<h5>Syntax:</h5>
6300<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6301 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]6302</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6303
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6304<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6305<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6306 function pointer suitable for executing it.</p>
6307
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6308<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6309<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6310 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6311 sufficiently aligned block of memory; this memory is written to by the
6312 intrinsic. Note that the size and the alignment are target-specific - LLVM
6313 currently provides no portable way of determining them, so a front-end that
6314 generates this intrinsic needs to have some target-specific knowledge.
6315 The <tt>func</tt> argument must hold a function bitcast to
6316 an <tt>i8*</tt>.</p>
6317
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6318<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6319<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6320 dependent code, turning it into a function. A pointer to this function is
6321 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6322 function pointer type</a> before being called. The new function's signature
6323 is the same as that of <tt>func</tt> with any arguments marked with
6324 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6325 is allowed, and it must be of pointer type. Calling the new function is
6326 equivalent to calling <tt>func</tt> with the same argument list, but
6327 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6328 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6329 by <tt>tramp</tt> is modified, then the effect of any later call to the
6330 returned function pointer is undefined.</p>
6331
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]6332</div>
6333
6334<!-- ======================================================================= -->
6335<div class="doc_subsection">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6336 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6337</div>
6338
6339<div class="doc_text">
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6340
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6341<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6342 hardware constructs for atomic operations and memory synchronization. This
6343 provides an interface to the hardware, not an interface to the programmer. It
6344 is aimed at a low enough level to allow any programming models or APIs
6345 (Application Programming Interfaces) which need atomic behaviors to map
6346 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6347 hardware provides a "universal IR" for source languages, it also provides a
6348 starting point for developing a "universal" atomic operation and
6349 synchronization IR.</p>
6350
6351<p>These do <em>not</em> form an API such as high-level threading libraries,
6352 software transaction memory systems, atomic primitives, and intrinsic
6353 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6354 application libraries. The hardware interface provided by LLVM should allow
6355 a clean implementation of all of these APIs and parallel programming models.
6356 No one model or paradigm should be selected above others unless the hardware
6357 itself ubiquitously does so.</p>
6358
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6359</div>
6360
6361<!-- _______________________________________________________________________ -->
6362<div class="doc_subsubsection">
6363 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6364</div>
6365<div class="doc_text">
6366<h5>Syntax:</h5>
6367<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6368 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]6369</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6370
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6371<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6372<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6373 specific pairs of memory access types.</p>
6374
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6375<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6376<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6377 The first four arguments enables a specific barrier as listed below. The
6378 fith argument specifies that the barrier applies to io or device or uncached
6379 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6380
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6381<ul>
6382 <li><tt>ll</tt>: load-load barrier</li>
6383 <li><tt>ls</tt>: load-store barrier</li>
6384 <li><tt>sl</tt>: store-load barrier</li>
6385 <li><tt>ss</tt>: store-store barrier</li>
6386 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6387</ul>
6388
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6389<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6390<p>This intrinsic causes the system to enforce some ordering constraints upon
6391 the loads and stores of the program. This barrier does not
6392 indicate <em>when</em> any events will occur, it only enforces
6393 an <em>order</em> in which they occur. For any of the specified pairs of load
6394 and store operations (f.ex. load-load, or store-load), all of the first
6395 operations preceding the barrier will complete before any of the second
6396 operations succeeding the barrier begin. Specifically the semantics for each
6397 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6398
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6399<ul>
6400 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6401 after the barrier begins.</li>
6402 <li><tt>ls</tt>: All loads before the barrier must complete before any
6403 store after the barrier begins.</li>
6404 <li><tt>ss</tt>: All stores before the barrier must complete before any
6405 store after the barrier begins.</li>
6406 <li><tt>sl</tt>: All stores before the barrier must complete before any
6407 load after the barrier begins.</li>
6408</ul>
6409
6410<p>These semantics are applied with a logical "and" behavior when more than one
6411 is enabled in a single memory barrier intrinsic.</p>
6412
6413<p>Backends may implement stronger barriers than those requested when they do
6414 not support as fine grained a barrier as requested. Some architectures do
6415 not need all types of barriers and on such architectures, these become
6416 noops.</p>
6417
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6418<h5>Example:</h5>
6419<pre>
6420%ptr = malloc i32
6421 store i32 4, %ptr
6422
6423%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6424 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6425 <i>; guarantee the above finishes</i>
6426 store i32 8, %ptr <i>; before this begins</i>
6427</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6428
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6429</div>
6430
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6431<!-- _______________________________________________________________________ -->
6432<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6433 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6434</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6435
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6436<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6437
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6438<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6439<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6440 any integer bit width and for different address spaces. Not all targets
6441 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6442
6443<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6444 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6445 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6446 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6447 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]6448</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6449
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6450<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6451<p>This loads a value in memory and compares it to a given value. If they are
6452 equal, it stores a new value into the memory.</p>
6453
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6454<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6455<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6456 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6457 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6458 this integer type. While any bit width integer may be used, targets may only
6459 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6460
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6461<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6462<p>This entire intrinsic must be executed atomically. It first loads the value
6463 in memory pointed to by <tt>ptr</tt> and compares it with the
6464 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6465 memory. The loaded value is yielded in all cases. This provides the
6466 equivalent of an atomic compare-and-swap operation within the SSA
6467 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6468
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6469<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6470<pre>
6471%ptr = malloc i32
6472 store i32 4, %ptr
6473
6474%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6475%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6476 <i>; yields {i32}:result1 = 4</i>
6477%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6478%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6479
6480%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6481%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6482 <i>; yields {i32}:result2 = 8</i>
6483%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6484
6485%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6486</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6487
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6488</div>
6489
6490<!-- _______________________________________________________________________ -->
6491<div class="doc_subsubsection">
6492 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6493</div>
6494<div class="doc_text">
6495<h5>Syntax:</h5>
6496
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6497<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6498 integer bit width. Not all targets support all bit widths however.</p>
6499
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6500<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6501 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6502 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6503 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6504 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]6505</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6506
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6507<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6508<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6509 the value from memory. It then stores the value in <tt>val</tt> in the memory
6510 at <tt>ptr</tt>.</p>
6511
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6512<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6513<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
6514 the <tt>val</tt> argument and the result must be integers of the same bit
6515 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6516 integer type. The targets may only lower integer representations they
6517 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6518
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6519<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6520<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6521 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6522 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6523
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6524<h5>Examples:</h5>
6525<pre>
6526%ptr = malloc i32
6527 store i32 4, %ptr
6528
6529%val1 = add i32 4, 4
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6530%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6531 <i>; yields {i32}:result1 = 4</i>
6532%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6533%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6534
6535%val2 = add i32 1, 1
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6536%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6537 <i>; yields {i32}:result2 = 8</i>
6538
6539%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6540%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6541</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6542
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6543</div>
6544
6545<!-- _______________________________________________________________________ -->
6546<div class="doc_subsubsection">
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6547 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6548
6549</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6550
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6551<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6552
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6553<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6554<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
6555 any integer bit width. Not all targets support all bit widths however.</p>
6556
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6557<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6558 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6559 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6560 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6561 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]6562</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6563
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6564<h5>Overview:</h5>
6565<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
6566 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6567
6568<h5>Arguments:</h5>
6569<p>The intrinsic takes two arguments, the first a pointer to an integer value
6570 and the second an integer value. The result is also an integer value. These
6571 integer types can have any bit width, but they must all have the same bit
6572 width. The targets may only lower integer representations they support.</p>
6573
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6574<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6575<p>This intrinsic does a series of operations atomically. It first loads the
6576 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6577 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]6578
6579<h5>Examples:</h5>
6580<pre>
6581%ptr = malloc i32
6582 store i32 4, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6583%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6584 <i>; yields {i32}:result1 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6585%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6586 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6587%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6588 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6589%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6590</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6591
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]6592</div>
6593
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6594<!-- _______________________________________________________________________ -->
6595<div class="doc_subsubsection">
6596 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6597
6598</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6599
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6600<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6601
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6602<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6603<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
6604 any integer bit width and for different address spaces. Not all targets
6605 support all bit widths however.</p>
6606
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6607<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6608 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6609 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6610 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6611 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]6612</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6613
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6614<h5>Overview:</h5>
6615<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6616 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6617
6618<h5>Arguments:</h5>
6619<p>The intrinsic takes two arguments, the first a pointer to an integer value
6620 and the second an integer value. The result is also an integer value. These
6621 integer types can have any bit width, but they must all have the same bit
6622 width. The targets may only lower integer representations they support.</p>
6623
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6624<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6625<p>This intrinsic does a series of operations atomically. It first loads the
6626 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6627 result to <tt>ptr</tt>. It yields the original value stored
6628 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6629
6630<h5>Examples:</h5>
6631<pre>
6632%ptr = malloc i32
6633 store i32 8, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6634%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6635 <i>; yields {i32}:result1 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6636%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6637 <i>; yields {i32}:result2 = 4</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6638%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6639 <i>; yields {i32}:result3 = 2</i>
6640%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6641</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6642
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6643</div>
6644
6645<!-- _______________________________________________________________________ -->
6646<div class="doc_subsubsection">
6647 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6648 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6649 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6650 <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]6651</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6652
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6653<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6654
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6655<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6656<p>These are overloaded intrinsics. You can
6657 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
6658 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
6659 bit width and for different address spaces. Not all targets support all bit
6660 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6661
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6662<pre>
6663 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6664 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6665 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6666 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]6667</pre>
6668
6669<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6670 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6671 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6672 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6673 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]6674</pre>
6675
6676<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6677 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6678 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6679 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6680 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]6681</pre>
6682
6683<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6684 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6685 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6686 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6687 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]6688</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6689
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6690<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6691<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6692 the value stored in memory at <tt>ptr</tt>. It yields the original value
6693 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6694
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6695<h5>Arguments:</h5>
6696<p>These intrinsics take two arguments, the first a pointer to an integer value
6697 and the second an integer value. The result is also an integer value. These
6698 integer types can have any bit width, but they must all have the same bit
6699 width. The targets may only lower integer representations they support.</p>
6700
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6701<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6702<p>These intrinsics does a series of operations atomically. They first load the
6703 value stored at <tt>ptr</tt>. They then do the bitwise
6704 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
6705 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6706
6707<h5>Examples:</h5>
6708<pre>
6709%ptr = malloc i32
6710 store i32 0x0F0F, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6711%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6712 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6713%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6714 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6715%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6716 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6717%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6718 <i>; yields {i32}:result3 = FF</i>
6719%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6720</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6721
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6722</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6723
6724<!-- _______________________________________________________________________ -->
6725<div class="doc_subsubsection">
6726 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6727 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6728 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6729 <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]6730</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6731
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6732<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6733
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6734<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6735<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6736 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
6737 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6738 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6739
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6740<pre>
6741 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6742 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6743 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6744 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]6745</pre>
6746
6747<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6748 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6749 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6750 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6751 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]6752</pre>
6753
6754<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6755 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6756 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6757 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6758 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]6759</pre>
6760
6761<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6762 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6763 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6764 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6765 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]6766</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6767
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6768<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6769<p>These intrinsics takes the signed or unsigned minimum or maximum of
6770 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6771 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6772
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6773<h5>Arguments:</h5>
6774<p>These intrinsics take two arguments, the first a pointer to an integer value
6775 and the second an integer value. The result is also an integer value. These
6776 integer types can have any bit width, but they must all have the same bit
6777 width. The targets may only lower integer representations they support.</p>
6778
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6779<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6780<p>These intrinsics does a series of operations atomically. They first load the
6781 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
6782 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
6783 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6784
6785<h5>Examples:</h5>
6786<pre>
6787%ptr = malloc i32
6788 store i32 7, %ptr
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6789%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6790 <i>; yields {i32}:result0 = 7</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6791%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6792 <i>; yields {i32}:result1 = -2</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6793%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6794 <i>; yields {i32}:result2 = 8</i>
Mon P Wange3b3a722008-07-30 04:36:53 +0000[diff] [blame]6795%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6796 <i>; yields {i32}:result3 = 8</i>
6797%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6798</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6799
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]6800</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]6801
6802<!-- ======================================================================= -->
6803<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6804 <a name="int_general">General Intrinsics</a>
6805</div>
6806
6807<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6808
6809<p>This class of intrinsics is designed to be generic and has no specific
6810 purpose.</p>
6811
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6812</div>
6813
6814<!-- _______________________________________________________________________ -->
6815<div class="doc_subsubsection">
6816 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6817</div>
6818
6819<div class="doc_text">
6820
6821<h5>Syntax:</h5>
6822<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]6823 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]6824</pre>
6825
6826<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6827<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6828
6829<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6830<p>The first argument is a pointer to a value, the second is a pointer to a
6831 global string, the third is a pointer to a global string which is the source
6832 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6833
6834<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6835<p>This intrinsic allows annotation of local variables with arbitrary strings.
6836 This can be useful for special purpose optimizations that want to look for
6837 these annotations. These have no other defined use, they are ignored by code
6838 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6839
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]6840</div>
6841
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6842<!-- _______________________________________________________________________ -->
6843<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]6844 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6845</div>
6846
6847<div class="doc_text">
6848
6849<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6850<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6851 any integer bit width.</p>
6852
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6853<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]6854 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6855 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6856 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6857 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6858 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]6859</pre>
6860
6861<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6862<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6863
6864<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6865<p>The first argument is an integer value (result of some expression), the
6866 second is a pointer to a global string, the third is a pointer to a global
6867 string which is the source file name, and the last argument is the line
6868 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6869
6870<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6871<p>This intrinsic allows annotations to be put on arbitrary expressions with
6872 arbitrary strings. This can be useful for special purpose optimizations that
6873 want to look for these annotations. These have no other defined use, they
6874 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6875
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]6876</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]6877
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6878<!-- _______________________________________________________________________ -->
6879<div class="doc_subsubsection">
6880 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6881</div>
6882
6883<div class="doc_text">
6884
6885<h5>Syntax:</h5>
6886<pre>
6887 declare void @llvm.trap()
6888</pre>
6889
6890<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6891<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6892
6893<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6894<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6895
6896<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6897<p>This intrinsics is lowered to the target dependent trap instruction. If the
6898 target does not have a trap instruction, this intrinsic will be lowered to
6899 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6900
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]6901</div>
6902
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6903<!-- _______________________________________________________________________ -->
6904<div class="doc_subsubsection">
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]6905 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6906</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6907
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6908<div class="doc_text">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6909
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6910<h5>Syntax:</h5>
6911<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6912 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6913</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6914
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6915<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6916<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
6917 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
6918 ensure that it is placed on the stack before local variables.</p>
6919
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6920<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6921<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
6922 arguments. The first argument is the value loaded from the stack
6923 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
6924 that has enough space to hold the value of the guard.</p>
6925
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6926<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6927<p>This intrinsic causes the prologue/epilogue inserter to force the position of
6928 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6929 stack. This is to ensure that if a local variable on the stack is
6930 overwritten, it will destroy the value of the guard. When the function exits,
6931 the guard on the stack is checked against the original guard. If they're
6932 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
6933 function.</p>
6934
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]6935</div>
6936
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6937<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]6938<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6939<address>
6940 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6941 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6942 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]6943 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]6944
6945 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]6946 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]6947 Last modified: $Date$
6948</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]6949
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6950</body>
6951</html>