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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 284d992777d6364962037eb71082547507275765 / . / 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.">
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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>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a></li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]24 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]25 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]26 <li><a href="#functionstructure">Functions</a></li>
Anton Korobeynikovc6c98af2007-04-29 18:02:48 +0000[diff] [blame]27 <li><a href="#aliasstructure">Aliases</a>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]28 <li><a href="#paramattrs">Parameter Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]29 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]30 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]31 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]32 </ol>
33 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]34 <li><a href="#typesystem">Type System</a>
35 <ol>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]36 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]37 <ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]38 <li><a href="#t_classifications">Type Classifications</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]39 </ol>
40 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]41 <li><a href="#t_derived">Derived Types</a>
42 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]43 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]44 <li><a href="#t_function">Function Type</a></li>
45 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]46 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]47 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]48 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]49 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]50 </ol>
51 </li>
52 </ol>
53 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]54 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]55 <ol>
56 <li><a href="#simpleconstants">Simple Constants</a>
57 <li><a href="#aggregateconstants">Aggregate Constants</a>
58 <li><a href="#globalconstants">Global Variable and Function Addresses</a>
59 <li><a href="#undefvalues">Undefined Values</a>
60 <li><a href="#constantexprs">Constant Expressions</a>
61 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]62 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]63 <li><a href="#othervalues">Other Values</a>
64 <ol>
65 <li><a href="#inlineasm">Inline Assembler Expressions</a>
66 </ol>
67 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]68 <li><a href="#instref">Instruction Reference</a>
69 <ol>
70 <li><a href="#terminators">Terminator Instructions</a>
71 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]72 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
73 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]74 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
75 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]76 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]77 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]78 </ol>
79 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]80 <li><a href="#binaryops">Binary Operations</a>
81 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]82 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
83 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
84 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]85 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
86 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
87 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]88 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
89 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
90 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]91 </ol>
92 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]93 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
94 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]95 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
96 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
97 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]98 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]99 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]100 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]101 </ol>
102 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]103 <li><a href="#vectorops">Vector Operations</a>
104 <ol>
105 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
106 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
107 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]108 </ol>
109 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]110 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]111 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]112 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
113 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
114 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]115 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
116 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
117 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]118 </ol>
119 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]120 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]121 <ol>
122 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
123 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
124 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
125 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
126 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]127 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
128 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
129 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
130 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]131 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
132 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]133 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]134 </ol>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]135 <li><a href="#otherops">Other Operations</a>
136 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]137 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
138 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]139 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]140 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]141 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]142 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]143 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]144 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]145 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]146 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]147 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]148 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]149 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
150 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]151 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
152 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
153 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]154 </ol>
155 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]156 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
157 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]158 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
159 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
160 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]161 </ol>
162 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]163 <li><a href="#int_codegen">Code Generator Intrinsics</a>
164 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]165 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
166 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
167 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
168 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
169 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
170 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
171 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]172 </ol>
173 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]174 <li><a href="#int_libc">Standard C Library Intrinsics</a>
175 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]176 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
177 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
178 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
179 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
180 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]181 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
182 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
183 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]184 </ol>
185 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]186 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]187 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]188 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]189 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
190 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
191 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]192 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
193 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]194 </ol>
195 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]196 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]197 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]198 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]199 <ol>
200 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]201 </ol>
202 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]203 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]204 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]205 <li><a href="#int_var_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]206 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]207 </ol>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]208 <ol>
209 <li><a href="#int_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]210 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]211 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]212 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]213 </ol>
214 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]215</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]216
217<div class="doc_author">
218 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
219 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]220</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]221
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]222<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]223<div class="doc_section"> <a name="abstract">Abstract </a></div>
224<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]225
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]226<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]227<p>This document is a reference manual for the LLVM assembly language.
228LLVM is an SSA based representation that provides type safety,
229low-level operations, flexibility, and the capability of representing
230'all' high-level languages cleanly. It is the common code
231representation used throughout all phases of the LLVM compilation
232strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]233</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]234
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]235<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]236<div class="doc_section"> <a name="introduction">Introduction</a> </div>
237<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]238
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]239<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]240
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]241<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]242different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]243representation (suitable for fast loading by a Just-In-Time compiler),
244and as a human readable assembly language representation. This allows
245LLVM to provide a powerful intermediate representation for efficient
246compiler transformations and analysis, while providing a natural means
247to debug and visualize the transformations. The three different forms
248of LLVM are all equivalent. This document describes the human readable
249representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]250
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]251<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]252while being expressive, typed, and extensible at the same time. It
253aims to be a "universal IR" of sorts, by being at a low enough level
254that high-level ideas may be cleanly mapped to it (similar to how
255microprocessors are "universal IR's", allowing many source languages to
256be mapped to them). By providing type information, LLVM can be used as
257the target of optimizations: for example, through pointer analysis, it
258can be proven that a C automatic variable is never accessed outside of
259the current function... allowing it to be promoted to a simple SSA
260value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]261
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]262</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]263
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]264<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]265<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]266
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]267<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]268
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]269<p>It is important to note that this document describes 'well formed'
270LLVM assembly language. There is a difference between what the parser
271accepts and what is considered 'well formed'. For example, the
272following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]273
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]274<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]275<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]276%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]277</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]278</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]279
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]280<p>...because the definition of <tt>%x</tt> does not dominate all of
281its uses. The LLVM infrastructure provides a verification pass that may
282be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]283automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]284the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]285by the verifier pass indicate bugs in transformation passes or input to
286the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]287</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]288
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]289<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]290
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]291<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]292<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]293<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]294
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]295<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]296
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]297 <p>LLVM identifiers come in two basic types: global and local. Global
298 identifiers (functions, global variables) begin with the @ character. Local
299 identifiers (register names, types) begin with the % character. Additionally,
300 there are three different formats for identifiers, for different purposes:
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]301
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]302<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]303 <li>Named values are represented as a string of characters with their prefix.
304 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
305 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]306 Identifiers which require other characters in their names can be surrounded
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]307 with quotes. In this way, anything except a <tt>&quot;</tt> character can
308 be used in a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]309
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]310 <li>Unnamed values are represented as an unsigned numeric value with their
311 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]312
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]313 <li>Constants, which are described in a <a href="#constants">section about
314 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]315</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]316
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]317<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]318don't need to worry about name clashes with reserved words, and the set of
319reserved words may be expanded in the future without penalty. Additionally,
320unnamed identifiers allow a compiler to quickly come up with a temporary
321variable without having to avoid symbol table conflicts.</p>
322
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]323<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]324languages. There are keywords for different opcodes
325('<tt><a href="#i_add">add</a></tt>',
326 '<tt><a href="#i_bitcast">bitcast</a></tt>',
327 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]328href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]329and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]330none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]331
332<p>Here is an example of LLVM code to multiply the integer variable
333'<tt>%X</tt>' by 8:</p>
334
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]335<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]336
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]337<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]338<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]339%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]340</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]341</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]342
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]343<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]344
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]345<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]346<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]347%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]348</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]349</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]350
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]351<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]352
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]353<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]354<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]355<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
356<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
357%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]358</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]359</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]360
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]361<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
362important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]363
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]364<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]365
366 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
367 line.</li>
368
369 <li>Unnamed temporaries are created when the result of a computation is not
370 assigned to a named value.</li>
371
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]372 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]373
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]374</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]375
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]376<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]377demonstrating instructions, we will follow an instruction with a comment that
378defines the type and name of value produced. Comments are shown in italic
379text.</p>
380
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]381</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]382
383<!-- *********************************************************************** -->
384<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
385<!-- *********************************************************************** -->
386
387<!-- ======================================================================= -->
388<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
389</div>
390
391<div class="doc_text">
392
393<p>LLVM programs are composed of "Module"s, each of which is a
394translation unit of the input programs. Each module consists of
395functions, global variables, and symbol table entries. Modules may be
396combined together with the LLVM linker, which merges function (and
397global variable) definitions, resolves forward declarations, and merges
398symbol table entries. Here is an example of the "hello world" module:</p>
399
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]400<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]401<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]402<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
403 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]404
405<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]406<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]407
408<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]409define i32 @main() { <i>; i32()* </i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]410 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]411 %cast210 = <a
Chris Lattner6c0955b2007-06-12 17:01:15 +0000[diff] [blame]412 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]413
414 <i>; Call puts function to write out the string to stdout...</i>
415 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]416 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]417 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]418 href="#i_ret">ret</a> i32 0<br>}<br>
419</pre>
420</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]421
422<p>This example is made up of a <a href="#globalvars">global variable</a>
423named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
424function, and a <a href="#functionstructure">function definition</a>
425for "<tt>main</tt>".</p>
426
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]427<p>In general, a module is made up of a list of global values,
428where both functions and global variables are global values. Global values are
429represented by a pointer to a memory location (in this case, a pointer to an
430array of char, and a pointer to a function), and have one of the following <a
431href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]432
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]433</div>
434
435<!-- ======================================================================= -->
436<div class="doc_subsection">
437 <a name="linkage">Linkage Types</a>
438</div>
439
440<div class="doc_text">
441
442<p>
443All Global Variables and Functions have one of the following types of linkage:
444</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]445
446<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]447
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]448 <dt><tt><b><a name="linkage_internal">internal</a></b></tt> </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]449
450 <dd>Global values with internal linkage are only directly accessible by
451 objects in the current module. In particular, linking code into a module with
452 an internal global value may cause the internal to be renamed as necessary to
453 avoid collisions. Because the symbol is internal to the module, all
454 references can be updated. This corresponds to the notion of the
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]455 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]456 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]457
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]458 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]459
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]460 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
461 the same name when linkage occurs. This is typically used to implement
462 inline functions, templates, or other code which must be generated in each
463 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
464 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]465 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]466
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]467 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]468
469 <dd>"<tt>weak</tt>" linkage is exactly the same as <tt>linkonce</tt> linkage,
470 except that unreferenced <tt>weak</tt> globals may not be discarded. This is
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]471 used for globals that may be emitted in multiple translation units, but that
472 are not guaranteed to be emitted into every translation unit that uses them.
473 One example of this are common globals in C, such as "<tt>int X;</tt>" at
474 global scope.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]475 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]476
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]477 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]478
479 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
480 pointer to array type. When two global variables with appending linkage are
481 linked together, the two global arrays are appended together. This is the
482 LLVM, typesafe, equivalent of having the system linker append together
483 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]484 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]485
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]486 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
487 <dd>The semantics of this linkage follow the ELF model: the symbol is weak
488 until linked, if not linked, the symbol becomes null instead of being an
489 undefined reference.
490 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]491
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]492 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]493
494 <dd>If none of the above identifiers are used, the global is externally
495 visible, meaning that it participates in linkage and can be used to resolve
496 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]497 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]498</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]499
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]500 <p>
501 The next two types of linkage are targeted for Microsoft Windows platform
502 only. They are designed to support importing (exporting) symbols from (to)
503 DLLs.
504 </p>
505
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]506 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]507 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
508
509 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
510 or variable via a global pointer to a pointer that is set up by the DLL
511 exporting the symbol. On Microsoft Windows targets, the pointer name is
512 formed by combining <code>_imp__</code> and the function or variable name.
513 </dd>
514
515 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
516
517 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
518 pointer to a pointer in a DLL, so that it can be referenced with the
519 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
520 name is formed by combining <code>_imp__</code> and the function or variable
521 name.
522 </dd>
523
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]524</dl>
525
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]526<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]527variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
528variable and was linked with this one, one of the two would be renamed,
529preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
530external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]531outside of the current module.</p>
532<p>It is illegal for a function <i>declaration</i>
533to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]534or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]535<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
536linkages.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]537</div>
538
539<!-- ======================================================================= -->
540<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]541 <a name="callingconv">Calling Conventions</a>
542</div>
543
544<div class="doc_text">
545
546<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
547and <a href="#i_invoke">invokes</a> can all have an optional calling convention
548specified for the call. The calling convention of any pair of dynamic
549caller/callee must match, or the behavior of the program is undefined. The
550following calling conventions are supported by LLVM, and more may be added in
551the future:</p>
552
553<dl>
554 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
555
556 <dd>This calling convention (the default if no other calling convention is
557 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]558 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]559 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]560 </dd>
561
562 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
563
564 <dd>This calling convention attempts to make calls as fast as possible
565 (e.g. by passing things in registers). This calling convention allows the
566 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner8cdc5bc2005-05-06 23:08:23 +0000[diff] [blame]567 without having to conform to an externally specified ABI. Implementations of
568 this convention should allow arbitrary tail call optimization to be supported.
569 This calling convention does not support varargs and requires the prototype of
570 all callees to exactly match the prototype of the function definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]571 </dd>
572
573 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
574
575 <dd>This calling convention attempts to make code in the caller as efficient
576 as possible under the assumption that the call is not commonly executed. As
577 such, these calls often preserve all registers so that the call does not break
578 any live ranges in the caller side. This calling convention does not support
579 varargs and requires the prototype of all callees to exactly match the
580 prototype of the function definition.
581 </dd>
582
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]583 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]584
585 <dd>Any calling convention may be specified by number, allowing
586 target-specific calling conventions to be used. Target specific calling
587 conventions start at 64.
588 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]589</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]590
591<p>More calling conventions can be added/defined on an as-needed basis, to
592support pascal conventions or any other well-known target-independent
593convention.</p>
594
595</div>
596
597<!-- ======================================================================= -->
598<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]599 <a name="visibility">Visibility Styles</a>
600</div>
601
602<div class="doc_text">
603
604<p>
605All Global Variables and Functions have one of the following visibility styles:
606</p>
607
608<dl>
609 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
610
611 <dd>On ELF, default visibility means that the declaration is visible to other
612 modules and, in shared libraries, means that the declared entity may be
613 overridden. On Darwin, default visibility means that the declaration is
614 visible to other modules. Default visibility corresponds to "external
615 linkage" in the language.
616 </dd>
617
618 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
619
620 <dd>Two declarations of an object with hidden visibility refer to the same
621 object if they are in the same shared object. Usually, hidden visibility
622 indicates that the symbol will not be placed into the dynamic symbol table,
623 so no other module (executable or shared library) can reference it
624 directly.
625 </dd>
626
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]627 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
628
629 <dd>On ELF, protected visibility indicates that the symbol will be placed in
630 the dynamic symbol table, but that references within the defining module will
631 bind to the local symbol. That is, the symbol cannot be overridden by another
632 module.
633 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]634</dl>
635
636</div>
637
638<!-- ======================================================================= -->
639<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]640 <a name="globalvars">Global Variables</a>
641</div>
642
643<div class="doc_text">
644
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]645<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]646instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]647an explicit section to be placed in, and may have an optional explicit alignment
648specified. A variable may be defined as "thread_local", which means that it
649will not be shared by threads (each thread will have a separated copy of the
650variable). A variable may be defined as a global "constant," which indicates
651that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]652optimization, allowing the global data to be placed in the read-only section of
653an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]654cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]655
656<p>
657LLVM explicitly allows <em>declarations</em> of global variables to be marked
658constant, even if the final definition of the global is not. This capability
659can be used to enable slightly better optimization of the program, but requires
660the language definition to guarantee that optimizations based on the
661'constantness' are valid for the translation units that do not include the
662definition.
663</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]664
665<p>As SSA values, global variables define pointer values that are in
666scope (i.e. they dominate) all basic blocks in the program. Global
667variables always define a pointer to their "content" type because they
668describe a region of memory, and all memory objects in LLVM are
669accessed through pointers.</p>
670
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame^]671<p>A global variable may be declared to reside in a target-specifc numbered
672address space. For targets that support them, address spaces may affect how
673optimizations are performed and/or what target instructions are used to access
674the variable. The default address space is zero.</p>
675
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]676<p>LLVM allows an explicit section to be specified for globals. If the target
677supports it, it will emit globals to the section specified.</p>
678
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]679<p>An explicit alignment may be specified for a global. If not present, or if
680the alignment is set to zero, the alignment of the global is set by the target
681to whatever it feels convenient. If an explicit alignment is specified, the
682global is forced to have at least that much alignment. All alignments must be
683a power of 2.</p>
684
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame^]685<p>For example, the following defines a global in a numbered address space with
686an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]687
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]688<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]689<pre>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame^]690@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]691</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]692</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]693
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]694</div>
695
696
697<!-- ======================================================================= -->
698<div class="doc_subsection">
699 <a name="functionstructure">Functions</a>
700</div>
701
702<div class="doc_text">
703
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]704<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
705an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]706<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]707<a href="#callingconv">calling convention</a>, a return type, an optional
708<a href="#paramattrs">parameter attribute</a> for the return type, a function
709name, a (possibly empty) argument list (each with optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]710<a href="#paramattrs">parameter attributes</a>), an optional section, an
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]711optional alignment, an optional <a href="#gc">garbage collector name</a>, an
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]712opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]713
714LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
715optional <a href="#linkage">linkage type</a>, an optional
716<a href="#visibility">visibility style</a>, an optional
717<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]718<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]719name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]720<a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]721
722<p>A function definition contains a list of basic blocks, forming the CFG for
723the function. Each basic block may optionally start with a label (giving the
724basic block a symbol table entry), contains a list of instructions, and ends
725with a <a href="#terminators">terminator</a> instruction (such as a branch or
726function return).</p>
727
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]728<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]729executed on entrance to the function, and it is not allowed to have predecessor
730basic blocks (i.e. there can not be any branches to the entry block of a
731function). Because the block can have no predecessors, it also cannot have any
732<a href="#i_phi">PHI nodes</a>.</p>
733
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]734<p>LLVM allows an explicit section to be specified for functions. If the target
735supports it, it will emit functions to the section specified.</p>
736
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]737<p>An explicit alignment may be specified for a function. If not present, or if
738the alignment is set to zero, the alignment of the function is set by the target
739to whatever it feels convenient. If an explicit alignment is specified, the
740function is forced to have at least that much alignment. All alignments must be
741a power of 2.</p>
742
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]743</div>
744
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]745
746<!-- ======================================================================= -->
747<div class="doc_subsection">
748 <a name="aliasstructure">Aliases</a>
749</div>
750<div class="doc_text">
751 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikova80e1182007-04-28 13:45:00 +0000[diff] [blame]752 function or global variable or bitcast of global value). Aliases may have an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]753 optional <a href="#linkage">linkage type</a>, and an
754 optional <a href="#visibility">visibility style</a>.</p>
755
756 <h5>Syntax:</h5>
757
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]758<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]759<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]760@&lt;Name&gt; = [Linkage] [Visibility] alias &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]761</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]762</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]763
764</div>
765
766
767
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]768<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]769<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
770<div class="doc_text">
771 <p>The return type and each parameter of a function type may have a set of
772 <i>parameter attributes</i> associated with them. Parameter attributes are
773 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]774 a function. Parameter attributes are considered to be part of the function,
775 not of the function type, so functions with different parameter attributes
776 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]777
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]778 <p>Parameter attributes are simple keywords that follow the type specified. If
779 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]780 example:</p>
781
782<div class="doc_code">
783<pre>
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]784declare i32 @printf(i8* noalias , ...) nounwind
785declare i32 @atoi(i8*) nounwind readonly
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]786</pre>
787</div>
788
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]789 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
790 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]791
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]792 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]793 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]794 <dt><tt>zeroext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]795 <dd>This indicates that the parameter should be zero extended just before
796 a call to this function.</dd>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]797 <dt><tt>signext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]798 <dd>This indicates that the parameter should be sign extended just before
799 a call to this function.</dd>
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]800 <dt><tt>inreg</tt></dt>
801 <dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000[diff] [blame]802 possible) during assembling function call. Support for this attribute is
803 target-specific</dd>
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]804 <dt><tt>sret</tt></dt>
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000[diff] [blame]805 <dd>This indicates that the parameter specifies the address of a structure
Reid Spencer67606122007-03-22 02:02:11 +0000[diff] [blame]806 that is the return value of the function in the source program.</dd>
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]807 <dt><tt>noalias</tt></dt>
808 <dd>This indicates that the parameter not alias any other object or any
809 other "noalias" objects during the function call.
Reid Spencer2dc52012007-03-22 02:18:56 +0000[diff] [blame]810 <dt><tt>noreturn</tt></dt>
811 <dd>This function attribute indicates that the function never returns. This
812 indicates to LLVM that every call to this function should be treated as if
813 an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Reid Spencer67606122007-03-22 02:02:11 +0000[diff] [blame]814 <dt><tt>nounwind</tt></dt>
815 <dd>This function attribute indicates that the function type does not use
816 the unwind instruction and does not allow stack unwinding to propagate
817 through it.</dd>
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]818 <dt><tt>nest</tt></dt>
819 <dd>This indicates that the parameter can be excised using the
820 <a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sandsed4a2f12007-11-22 20:23:04 +0000[diff] [blame]821 <dt><tt>readonly</tt></dt>
Duncan Sandsf04d5842007-11-14 21:14:02 +0000[diff] [blame]822 <dd>This function attribute indicates that the function has no side-effects
Duncan Sandsed4a2f12007-11-22 20:23:04 +0000[diff] [blame]823 except for producing a return value or throwing an exception. The value
824 returned must only depend on the function arguments and/or global variables.
825 It may use values obtained by dereferencing pointers.</dd>
826 <dt><tt>readnone</tt></dt>
827 <dd>A <tt>readnone</tt> function has the same restrictions as a <tt>readonly</tt>
Duncan Sandsf04d5842007-11-14 21:14:02 +0000[diff] [blame]828 function, but in addition it is not allowed to dereference any pointer arguments
829 or global variables.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]830 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]831
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]832</div>
833
834<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]835<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]836 <a name="gc">Garbage Collector Names</a>
837</div>
838
839<div class="doc_text">
840<p>Each function may specify a garbage collector name, which is simply a
841string.</p>
842
843<div class="doc_code"><pre
844>define void @f() gc "name" { ...</pre></div>
845
846<p>The compiler declares the supported values of <i>name</i>. Specifying a
847collector which will cause the compiler to alter its output in order to support
848the named garbage collection algorithm.</p>
849</div>
850
851<!-- ======================================================================= -->
852<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]853 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]854</div>
855
856<div class="doc_text">
857<p>
858Modules may contain "module-level inline asm" blocks, which corresponds to the
859GCC "file scope inline asm" blocks. These blocks are internally concatenated by
860LLVM and treated as a single unit, but may be separated in the .ll file if
861desired. The syntax is very simple:
862</p>
863
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]864<div class="doc_code">
865<pre>
866module asm "inline asm code goes here"
867module asm "more can go here"
868</pre>
869</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]870
871<p>The strings can contain any character by escaping non-printable characters.
872 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
873 for the number.
874</p>
875
876<p>
877 The inline asm code is simply printed to the machine code .s file when
878 assembly code is generated.
879</p>
880</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]881
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]882<!-- ======================================================================= -->
883<div class="doc_subsection">
884 <a name="datalayout">Data Layout</a>
885</div>
886
887<div class="doc_text">
888<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]889data is to be laid out in memory. The syntax for the data layout is simply:</p>
890<pre> target datalayout = "<i>layout specification</i>"</pre>
891<p>The <i>layout specification</i> consists of a list of specifications
892separated by the minus sign character ('-'). Each specification starts with a
893letter and may include other information after the letter to define some
894aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]895<dl>
896 <dt><tt>E</tt></dt>
897 <dd>Specifies that the target lays out data in big-endian form. That is, the
898 bits with the most significance have the lowest address location.</dd>
899 <dt><tt>e</tt></dt>
900 <dd>Specifies that hte target lays out data in little-endian form. That is,
901 the bits with the least significance have the lowest address location.</dd>
902 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
903 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
904 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
905 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
906 too.</dd>
907 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
908 <dd>This specifies the alignment for an integer type of a given bit
909 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
910 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
911 <dd>This specifies the alignment for a vector type of a given bit
912 <i>size</i>.</dd>
913 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
914 <dd>This specifies the alignment for a floating point type of a given bit
915 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
916 (double).</dd>
917 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
918 <dd>This specifies the alignment for an aggregate type of a given bit
919 <i>size</i>.</dd>
920</dl>
921<p>When constructing the data layout for a given target, LLVM starts with a
922default set of specifications which are then (possibly) overriden by the
923specifications in the <tt>datalayout</tt> keyword. The default specifications
924are given in this list:</p>
925<ul>
926 <li><tt>E</tt> - big endian</li>
927 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
928 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
929 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
930 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
931 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
932 <li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
933 alignment of 64-bits</li>
934 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
935 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
936 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
937 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
938 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
939</ul>
940<p>When llvm is determining the alignment for a given type, it uses the
941following rules:
942<ol>
943 <li>If the type sought is an exact match for one of the specifications, that
944 specification is used.</li>
945 <li>If no match is found, and the type sought is an integer type, then the
946 smallest integer type that is larger than the bitwidth of the sought type is
947 used. If none of the specifications are larger than the bitwidth then the the
948 largest integer type is used. For example, given the default specifications
949 above, the i7 type will use the alignment of i8 (next largest) while both
950 i65 and i256 will use the alignment of i64 (largest specified).</li>
951 <li>If no match is found, and the type sought is a vector type, then the
952 largest vector type that is smaller than the sought vector type will be used
953 as a fall back. This happens because <128 x double> can be implemented in
954 terms of 64 <2 x double>, for example.</li>
955</ol>
956</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]957
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]958<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]959<div class="doc_section"> <a name="typesystem">Type System</a> </div>
960<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]961
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]962<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]963
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]964<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]965intermediate representation. Being typed enables a number of
966optimizations to be performed on the IR directly, without having to do
967extra analyses on the side before the transformation. A strong type
968system makes it easier to read the generated code and enables novel
969analyses and transformations that are not feasible to perform on normal
970three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]971
972</div>
973
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]974<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]975<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]976<div class="doc_text">
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]977<p>The primitive types are the fundamental building blocks of the LLVM
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]978system. The current set of primitive types is as follows:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]979
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]980<table class="layout">
981 <tr class="layout">
982 <td class="left">
983 <table>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]984 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]985 <tr><th>Type</th><th>Description</th></tr>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]986 <tr><td><tt><a name="t_void">void</a></tt></td><td>No value</td></tr>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]987 <tr><td><tt>label</tt></td><td>Branch destination</td></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]988 </tbody>
989 </table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]990 </td>
991 <td class="right">
992 <table>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]993 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]994 <tr><th>Type</th><th>Description</th></tr>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]995 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]996 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]997 </tbody>
998 </table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]999 </td>
1000 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1001</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1002</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1003
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1004<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1005<div class="doc_subsubsection"> <a name="t_classifications">Type
1006Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1007<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1008<p>These different primitive types fall into a few useful
1009classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1010
1011<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1012 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1013 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1014 <tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1015 <td><a name="t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1016 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1017 </tr>
1018 <tr>
1019 <td><a name="t_floating">floating point</a></td>
1020 <td><tt>float, double</tt></td>
1021 </tr>
1022 <tr>
1023 <td><a name="t_firstclass">first class</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1024 <td><tt>i1, ..., float, double, <br/>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1025 <a href="#t_pointer">pointer</a>,<a href="#t_vector">vector</a></tt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1026 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1027 </tr>
1028 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1029</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1030
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1031<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1032most important. Values of these types are the only ones which can be
1033produced by instructions, passed as arguments, or used as operands to
1034instructions. This means that all structures and arrays must be
1035manipulated either by pointer or by component.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1036</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1037
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1038<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1039<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1040
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1041<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1042
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1043<p>The real power in LLVM comes from the derived types in the system.
1044This is what allows a programmer to represent arrays, functions,
1045pointers, and other useful types. Note that these derived types may be
1046recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1047
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1048</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1049
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1050<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1051<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1052
1053<div class="doc_text">
1054
1055<h5>Overview:</h5>
1056<p>The integer type is a very simple derived type that simply specifies an
1057arbitrary bit width for the integer type desired. Any bit width from 1 bit to
10582^23-1 (about 8 million) can be specified.</p>
1059
1060<h5>Syntax:</h5>
1061
1062<pre>
1063 iN
1064</pre>
1065
1066<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1067value.</p>
1068
1069<h5>Examples:</h5>
1070<table class="layout">
1071 <tr class="layout">
1072 <td class="left">
1073 <tt>i1</tt><br/>
1074 <tt>i4</tt><br/>
1075 <tt>i8</tt><br/>
1076 <tt>i16</tt><br/>
1077 <tt>i32</tt><br/>
1078 <tt>i42</tt><br/>
1079 <tt>i64</tt><br/>
1080 <tt>i1942652</tt><br/>
1081 </td>
1082 <td class="left">
1083 A boolean integer of 1 bit<br/>
1084 A nibble sized integer of 4 bits.<br/>
1085 A byte sized integer of 8 bits.<br/>
1086 A half word sized integer of 16 bits.<br/>
1087 A word sized integer of 32 bits.<br/>
1088 An integer whose bit width is the answer. <br/>
1089 A double word sized integer of 64 bits.<br/>
1090 A really big integer of over 1 million bits.<br/>
1091 </td>
1092 </tr>
1093</table>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1094</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1095
1096<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1097<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1098
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1099<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1100
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1101<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1102
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1103<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1104sequentially in memory. The array type requires a size (number of
1105elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1106
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1107<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1108
1109<pre>
1110 [&lt;# elements&gt; x &lt;elementtype&gt;]
1111</pre>
1112
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1113<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1114be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1115
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1116<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1117<table class="layout">
1118 <tr class="layout">
1119 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1120 <tt>[40 x i32 ]</tt><br/>
1121 <tt>[41 x i32 ]</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1122 <tt>[40 x i8]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1123 </td>
1124 <td class="left">
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1125 Array of 40 32-bit integer values.<br/>
1126 Array of 41 32-bit integer values.<br/>
1127 Array of 40 8-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1128 </td>
1129 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1130</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1131<p>Here are some examples of multidimensional arrays:</p>
1132<table class="layout">
1133 <tr class="layout">
1134 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1135 <tt>[3 x [4 x i32]]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1136 <tt>[12 x [10 x float]]</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1137 <tt>[2 x [3 x [4 x i16]]]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1138 </td>
1139 <td class="left">
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1140 3x4 array of 32-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1141 12x10 array of single precision floating point values.<br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1142 2x3x4 array of 16-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1143 </td>
1144 </tr>
1145</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1146
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1147<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1148length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1149LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1150As a special case, however, zero length arrays are recognized to be variable
1151length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1152type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1153
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1154</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1155
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1156<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1157<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1158<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1159<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1160<p>The function type can be thought of as a function signature. It
1161consists of a return type and a list of formal parameter types.
John Criswell009900b2003-11-25 21:45:46 +0000[diff] [blame]1162Function types are usually used to build virtual function tables
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1163(which are structures of pointers to functions), for indirect function
1164calls, and when defining a function.</p>
John Criswell009900b2003-11-25 21:45:46 +0000[diff] [blame]1165<p>
1166The return type of a function type cannot be an aggregate type.
1167</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1168<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1169<pre> &lt;returntype&gt; (&lt;parameter list&gt;)<br></pre>
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1170<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Misha Brukmanc24b7582004-08-12 20:16:08 +0000[diff] [blame]1171specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1172which indicates that the function takes a variable number of arguments.
1173Variable argument functions can access their arguments with the <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1174 href="#int_varargs">variable argument handling intrinsic</a> functions.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1175<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1176<table class="layout">
1177 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1178 <td class="left"><tt>i32 (i32)</tt></td>
1179 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1180 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1181 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1182 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1183 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1184 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1185 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1186 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1187 <tt>float</tt>.
1188 </td>
1189 </tr><tr class="layout">
1190 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1191 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1192 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1193 which returns an integer. This is the signature for <tt>printf</tt> in
1194 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1195 </td>
1196 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1197</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1198
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1199</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1200<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1201<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1202<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1203<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1204<p>The structure type is used to represent a collection of data members
1205together in memory. The packing of the field types is defined to match
1206the ABI of the underlying processor. The elements of a structure may
1207be any type that has a size.</p>
1208<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1209and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1210field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1211instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1212<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1213<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1214<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1215<table class="layout">
1216 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1217 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1218 <td class="left">A triple of three <tt>i32</tt> values</td>
1219 </tr><tr class="layout">
1220 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1221 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1222 second element is a <a href="#t_pointer">pointer</a> to a
1223 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1224 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1225 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1226</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1227</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1228
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1229<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1230<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1231</div>
1232<div class="doc_text">
1233<h5>Overview:</h5>
1234<p>The packed structure type is used to represent a collection of data members
1235together in memory. There is no padding between fields. Further, the alignment
1236of a packed structure is 1 byte. The elements of a packed structure may
1237be any type that has a size.</p>
1238<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1239and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1240field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1241instruction.</p>
1242<h5>Syntax:</h5>
1243<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1244<h5>Examples:</h5>
1245<table class="layout">
1246 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1247 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1248 <td class="left">A triple of three <tt>i32</tt> values</td>
1249 </tr><tr class="layout">
1250 <td class="left"><tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}&nbsp;&gt;</tt></td>
1251 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1252 second element is a <a href="#t_pointer">pointer</a> to a
1253 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1254 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1255 </tr>
1256</table>
1257</div>
1258
1259<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1260<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1261<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1262<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1263<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame^]1264reference to another object, which must live in memory. Pointer types may have
1265an optional address space attribute defining the target-specific numbered
1266address space where the pointed-to object resides. The default address space is
1267zero.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1268<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1269<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1270<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1271<table class="layout">
1272 <tr class="layout">
1273 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1274 <tt>[4x i32]*</tt><br/>
1275 <tt>i32 (i32 *) *</tt><br/>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame^]1276 <tt>i32 addrspace(5)*</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1277 </td>
1278 <td class="left">
1279 A <a href="#t_pointer">pointer</a> to <a href="#t_array">array</a> of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1280 four <tt>i32</tt> values<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1281 A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1282 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
1283 <tt>i32</tt>.<br/>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame^]1284 A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value that resides
1285 in address space 5.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1286 </td>
1287 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1288</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1289</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1290
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1291<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1292<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1293<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1294
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1295<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1296
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1297<p>A vector type is a simple derived type that represents a vector
1298of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1299are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1300A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1301elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1302of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1303considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1304
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1305<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1306
1307<pre>
1308 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1309</pre>
1310
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1311<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1312be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1313
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1314<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1315
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1316<table class="layout">
1317 <tr class="layout">
1318 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1319 <tt>&lt;4 x i32&gt;</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1320 <tt>&lt;8 x float&gt;</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1321 <tt>&lt;2 x i64&gt;</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1322 </td>
1323 <td class="left">
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1324 Vector of 4 32-bit integer values.<br/>
1325 Vector of 8 floating-point values.<br/>
1326 Vector of 2 64-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1327 </td>
1328 </tr>
1329</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1330</div>
1331
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1332<!-- _______________________________________________________________________ -->
1333<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1334<div class="doc_text">
1335
1336<h5>Overview:</h5>
1337
1338<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1339corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1340In LLVM, opaque types can eventually be resolved to any type (not just a
1341structure type).</p>
1342
1343<h5>Syntax:</h5>
1344
1345<pre>
1346 opaque
1347</pre>
1348
1349<h5>Examples:</h5>
1350
1351<table class="layout">
1352 <tr class="layout">
1353 <td class="left">
1354 <tt>opaque</tt>
1355 </td>
1356 <td class="left">
1357 An opaque type.<br/>
1358 </td>
1359 </tr>
1360</table>
1361</div>
1362
1363
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1364<!-- *********************************************************************** -->
1365<div class="doc_section"> <a name="constants">Constants</a> </div>
1366<!-- *********************************************************************** -->
1367
1368<div class="doc_text">
1369
1370<p>LLVM has several different basic types of constants. This section describes
1371them all and their syntax.</p>
1372
1373</div>
1374
1375<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1376<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1377
1378<div class="doc_text">
1379
1380<dl>
1381 <dt><b>Boolean constants</b></dt>
1382
1383 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1384 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1385 </dd>
1386
1387 <dt><b>Integer constants</b></dt>
1388
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1389 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1390 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1391 integer types.
1392 </dd>
1393
1394 <dt><b>Floating point constants</b></dt>
1395
1396 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1397 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1398 notation (see below). Floating point constants must have a <a
1399 href="#t_floating">floating point</a> type. </dd>
1400
1401 <dt><b>Null pointer constants</b></dt>
1402
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1403 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1404 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1405
1406</dl>
1407
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1408<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1409of floating point constants. For example, the form '<tt>double
14100x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
14114.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1412(and the only time that they are generated by the disassembler) is when a
1413floating point constant must be emitted but it cannot be represented as a
1414decimal floating point number. For example, NaN's, infinities, and other
1415special values are represented in their IEEE hexadecimal format so that
1416assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1417
1418</div>
1419
1420<!-- ======================================================================= -->
1421<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1422</div>
1423
1424<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1425<p>Aggregate constants arise from aggregation of simple constants
1426and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1427
1428<dl>
1429 <dt><b>Structure constants</b></dt>
1430
1431 <dd>Structure constants are represented with notation similar to structure
1432 type definitions (a comma separated list of elements, surrounded by braces
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1433 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* %G }</tt>",
Chris Lattner3e63a9d2007-07-13 20:01:46 +0000[diff] [blame]1434 where "<tt>%G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1435 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1436 types of elements must match those specified by the type.
1437 </dd>
1438
1439 <dt><b>Array constants</b></dt>
1440
1441 <dd>Array constants are represented with notation similar to array type
1442 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1443 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1444 constants must have <a href="#t_array">array type</a>, and the number and
1445 types of elements must match those specified by the type.
1446 </dd>
1447
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1448 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1449
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1450 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1451 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1452 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32 42,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1453 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1454 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1455 match those specified by the type.
1456 </dd>
1457
1458 <dt><b>Zero initialization</b></dt>
1459
1460 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1461 value to zero of <em>any</em> type, including scalar and aggregate types.
1462 This is often used to avoid having to print large zero initializers (e.g. for
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1463 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1464 initializers.
1465 </dd>
1466</dl>
1467
1468</div>
1469
1470<!-- ======================================================================= -->
1471<div class="doc_subsection">
1472 <a name="globalconstants">Global Variable and Function Addresses</a>
1473</div>
1474
1475<div class="doc_text">
1476
1477<p>The addresses of <a href="#globalvars">global variables</a> and <a
1478href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1479constants. These constants are explicitly referenced when the <a
1480href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1481href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1482file:</p>
1483
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1484<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1485<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1486@X = global i32 17
1487@Y = global i32 42
1488@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1489</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1490</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1491
1492</div>
1493
1494<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1495<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1496<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1497 <p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1498 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1499 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1500
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1501 <p>Undefined values indicate to the compiler that the program is well defined
1502 no matter what value is used, giving the compiler more freedom to optimize.
1503 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1504</div>
1505
1506<!-- ======================================================================= -->
1507<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1508</div>
1509
1510<div class="doc_text">
1511
1512<p>Constant expressions are used to allow expressions involving other constants
1513to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1514href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1515that does not have side effects (e.g. load and call are not supported). The
1516following is the syntax for constant expressions:</p>
1517
1518<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1519 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1520 <dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1521 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1522
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1523 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1524 <dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1525 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1526
1527 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1528 <dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1529 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1530
1531 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1532 <dd>Truncate a floating point constant to another floating point type. The
1533 size of CST must be larger than the size of TYPE. Both types must be
1534 floating point.</dd>
1535
1536 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1537 <dd>Floating point extend a constant to another type. The size of CST must be
1538 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1539
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1540 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1541 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1542 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1543 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1544 of the same number of elements. If the value won't fit in the integer type,
1545 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1546
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1547 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1548 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1549 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1550 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1551 of the same number of elements. If the value won't fit in the integer type,
1552 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1553
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1554 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1555 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1556 constant. TYPE must be a scalar or vector floating point type. CST must be of
1557 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1558 of the same number of elements. If the value won't fit in the floating point
1559 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1560
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1561 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1562 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1563 constant. TYPE must be a scalar or vector floating point type. CST must be of
1564 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1565 of the same number of elements. If the value won't fit in the floating point
1566 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1567
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1568 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1569 <dd>Convert a pointer typed constant to the corresponding integer constant
1570 TYPE must be an integer type. CST must be of pointer type. The CST value is
1571 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1572
1573 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1574 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1575 pointer type. CST must be of integer type. The CST value is zero extended,
1576 truncated, or unchanged to make it fit in a pointer size. This one is
1577 <i>really</i> dangerous!</dd>
1578
1579 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1580 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1581 identical (same number of bits). The conversion is done as if the CST value
1582 was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1583 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1584 vector types to any other type, as long as they have the same bit width. For
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1585 pointers it is only valid to cast to another pointer type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1586 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1587
1588 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1589
1590 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1591 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1592 instruction, the index list may have zero or more indexes, which are required
1593 to make sense for the type of "CSTPTR".</dd>
1594
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1595 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1596
1597 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1598 constants.</dd>
1599
1600 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1601 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1602
1603 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1604 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1605
1606 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1607
1608 <dd>Perform the <a href="#i_extractelement">extractelement
1609 operation</a> on constants.
1610
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1611 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1612
1613 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1614 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1615
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1616
1617 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1618
1619 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1620 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1621
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1622 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1623
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1624 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1625 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1626 binary</a> operations. The constraints on operands are the same as those for
1627 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1628 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1629</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1630</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1631
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1632<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1633<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1634<!-- *********************************************************************** -->
1635
1636<!-- ======================================================================= -->
1637<div class="doc_subsection">
1638<a name="inlineasm">Inline Assembler Expressions</a>
1639</div>
1640
1641<div class="doc_text">
1642
1643<p>
1644LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1645Module-Level Inline Assembly</a>) through the use of a special value. This
1646value represents the inline assembler as a string (containing the instructions
1647to emit), a list of operand constraints (stored as a string), and a flag that
1648indicates whether or not the inline asm expression has side effects. An example
1649inline assembler expression is:
1650</p>
1651
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1652<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1653<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1654i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1655</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1656</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1657
1658<p>
1659Inline assembler expressions may <b>only</b> be used as the callee operand of
1660a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1661</p>
1662
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1663<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1664<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1665%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]1666</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1667</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1668
1669<p>
1670Inline asms with side effects not visible in the constraint list must be marked
1671as having side effects. This is done through the use of the
1672'<tt>sideeffect</tt>' keyword, like so:
1673</p>
1674
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1675<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1676<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1677call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1678</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1679</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1680
1681<p>TODO: The format of the asm and constraints string still need to be
1682documented here. Constraints on what can be done (e.g. duplication, moving, etc
1683need to be documented).
1684</p>
1685
1686</div>
1687
1688<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1689<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1690<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1691
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1692<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1693
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1694<p>The LLVM instruction set consists of several different
1695classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1696instructions</a>, <a href="#binaryops">binary instructions</a>,
1697<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1698 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1699instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1700
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1701</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1702
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1703<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1704<div class="doc_subsection"> <a name="terminators">Terminator
1705Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1706
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1707<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1708
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1709<p>As mentioned <a href="#functionstructure">previously</a>, every
1710basic block in a program ends with a "Terminator" instruction, which
1711indicates which block should be executed after the current block is
1712finished. These terminator instructions typically yield a '<tt>void</tt>'
1713value: they produce control flow, not values (the one exception being
1714the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1715<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1716 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1717instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1718the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1719 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1720 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1721
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1722</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1723
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1724<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1725<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1726Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1727<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1728<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1729<pre> 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]1730 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1731</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1732<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1733<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1734value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]1735<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1736returns a value and then causes control flow, and one that just causes
1737control flow to occur.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1738<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1739<p>The '<tt>ret</tt>' instruction may return any '<a
1740 href="#t_firstclass">first class</a>' type. Notice that a function is
1741not <a href="#wellformed">well formed</a> if there exists a '<tt>ret</tt>'
1742instruction inside of the function that returns a value that does not
1743match the return type of the function.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1744<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1745<p>When the '<tt>ret</tt>' instruction is executed, control flow
1746returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]1747 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1748the instruction after the call. If the caller was an "<a
1749 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1750at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1751returns a value, that value shall set the call or invoke instruction's
1752return value.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1753<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1754<pre> ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1755 ret void <i>; Return from a void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1756</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1757</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1758<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1759<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1760<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1761<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1762<pre> 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]1763</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1764<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1765<p>The '<tt>br</tt>' instruction is used to cause control flow to
1766transfer to a different basic block in the current function. There are
1767two forms of this instruction, corresponding to a conditional branch
1768and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1769<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1770<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1771single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1772unconditional form of the '<tt>br</tt>' instruction takes a single
1773'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1774<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1775<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1776argument is evaluated. If the value is <tt>true</tt>, control flows
1777to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1778control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1779<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1780<pre>Test:<br> %cond = <a href="#i_icmp">icmp</a> eq, i32 %a, %b<br> br i1 %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1781 href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1782</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1783<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1784<div class="doc_subsubsection">
1785 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1786</div>
1787
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1788<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1789<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1790
1791<pre>
1792 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1793</pre>
1794
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1795<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1796
1797<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1798several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1799instruction, allowing a branch to occur to one of many possible
1800destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1801
1802
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1803<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1804
1805<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1806comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1807an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1808table is not allowed to contain duplicate constant entries.</p>
1809
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1810<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1811
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1812<p>The <tt>switch</tt> instruction specifies a table of values and
1813destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1814table is searched for the given value. If the value is found, control flow is
1815transfered to the corresponding destination; otherwise, control flow is
1816transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1817
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1818<h5>Implementation:</h5>
1819
1820<p>Depending on properties of the target machine and the particular
1821<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1822ways. For example, it could be generated as a series of chained conditional
1823branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1824
1825<h5>Example:</h5>
1826
1827<pre>
1828 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1829 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1830 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1831
1832 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1833 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1834
1835 <i>; Implement a jump table:</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1836 switch i32 %val, label %otherwise [ i32 0, label %onzero
1837 i32 1, label %onone
1838 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1839</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1840</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1841
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1842<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1843<div class="doc_subsubsection">
1844 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
1845</div>
1846
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1847<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1848
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1849<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1850
1851<pre>
1852 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] &lt;ptr to function ty&gt; %&lt;function ptr val&gt;(&lt;function args&gt;)
Chris Lattner76b8a332006-05-14 18:23:06 +0000[diff] [blame]1853 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1854</pre>
1855
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]1856<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1857
1858<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
1859function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1860'<tt>normal</tt>' label or the
1861'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1862"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
1863"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1864href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
1865continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1866
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1867<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1868
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1869<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1870
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1871<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1872 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]1873 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1874 convention</a> the call should use. If none is specified, the call defaults
1875 to using C calling conventions.
1876 </li>
1877 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
1878 function value being invoked. In most cases, this is a direct function
1879 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
1880 an arbitrary pointer to function value.
1881 </li>
1882
1883 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
1884 function to be invoked. </li>
1885
1886 <li>'<tt>function args</tt>': argument list whose types match the function
1887 signature argument types. If the function signature indicates the function
1888 accepts a variable number of arguments, the extra arguments can be
1889 specified. </li>
1890
1891 <li>'<tt>normal label</tt>': the label reached when the called function
1892 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
1893
1894 <li>'<tt>exception label</tt>': the label reached when a callee returns with
1895 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
1896
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1897</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1898
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1899<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1900
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1901<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1902href="#i_call">call</a></tt>' instruction in most regards. The primary
1903difference is that it establishes an association with a label, which is used by
1904the runtime library to unwind the stack.</p>
1905
1906<p>This instruction is used in languages with destructors to ensure that proper
1907cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
1908exception. Additionally, this is important for implementation of
1909'<tt>catch</tt>' clauses in high-level languages that support them.</p>
1910
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1911<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1912<pre>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1913 %retval = invoke i32 %Test(i32 15) to label %Continue
1914 unwind label %TestCleanup <i>; {i32}:retval set</i>
1915 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Test(i32 15) to label %Continue
1916 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1917</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1918</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1919
1920
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1921<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1922
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1923<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
1924Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1925
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1926<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1927
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1928<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1929<pre>
1930 unwind
1931</pre>
1932
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1933<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1934
1935<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
1936at the first callee in the dynamic call stack which used an <a
1937href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
1938primarily used to implement exception handling.</p>
1939
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1940<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1941
1942<p>The '<tt>unwind</tt>' intrinsic causes execution of the current function to
1943immediately halt. The dynamic call stack is then searched for the first <a
1944href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
1945execution continues at the "exceptional" destination block specified by the
1946<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
1947dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1948</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1949
1950<!-- _______________________________________________________________________ -->
1951
1952<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
1953Instruction</a> </div>
1954
1955<div class="doc_text">
1956
1957<h5>Syntax:</h5>
1958<pre>
1959 unreachable
1960</pre>
1961
1962<h5>Overview:</h5>
1963
1964<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
1965instruction is used to inform the optimizer that a particular portion of the
1966code is not reachable. This can be used to indicate that the code after a
1967no-return function cannot be reached, and other facts.</p>
1968
1969<h5>Semantics:</h5>
1970
1971<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
1972</div>
1973
1974
1975
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1976<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1977<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1978<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1979<p>Binary operators are used to do most of the computation in a
1980program. They require two operands, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1981produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1982multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1983The result value of a binary operator is not
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1984necessarily the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1985<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1986</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1987<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1988<div class="doc_subsubsection"> <a name="i_add">'<tt>add</tt>'
1989Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1990<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1991<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1992<pre> &lt;result&gt; = add &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1993</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1994<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1995<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1996<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1997<p>The two arguments to the '<tt>add</tt>' instruction must be either <a
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1998 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a> values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1999 This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2000Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2001<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2002<p>The value produced is the integer or floating point sum of the two
2003operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2004<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2005<pre> &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2006</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2007</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2008<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2009<div class="doc_subsubsection"> <a name="i_sub">'<tt>sub</tt>'
2010Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2011<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2012<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2013<pre> &lt;result&gt; = sub &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2014</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2015<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2016<p>The '<tt>sub</tt>' instruction returns the difference of its two
2017operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2018<p>Note that the '<tt>sub</tt>' instruction is used to represent the '<tt>neg</tt>'
2019instruction present in most other intermediate representations.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2020<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2021<p>The two arguments to the '<tt>sub</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2022 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2023values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2024This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2025Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2026<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2027<p>The value produced is the integer or floating point difference of
2028the two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2029<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2030<pre>
2031 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2032 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2033</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2034</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2035<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2036<div class="doc_subsubsection"> <a name="i_mul">'<tt>mul</tt>'
2037Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2038<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2039<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2040<pre> &lt;result&gt; = mul &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2041</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2042<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2043<p>The '<tt>mul</tt>' instruction returns the product of its two
2044operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2045<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2046<p>The two arguments to the '<tt>mul</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2047 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2048values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2049This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2050Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2051<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2052<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2053two operands.</p>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]2054<p>Because the operands are the same width, the result of an integer
2055multiplication is the same whether the operands should be deemed unsigned or
2056signed.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2057<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2058<pre> &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2059</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2060</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2061<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2062<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2063</a></div>
2064<div class="doc_text">
2065<h5>Syntax:</h5>
2066<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2067</pre>
2068<h5>Overview:</h5>
2069<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2070operands.</p>
2071<h5>Arguments:</h5>
2072<p>The two arguments to the '<tt>udiv</tt>' instruction must be
2073<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2074types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2075of the values in which case the elements must be integers.</p>
2076<h5>Semantics:</h5>
2077<p>The value produced is the unsigned integer quotient of the two operands. This
2078instruction always performs an unsigned division operation, regardless of
2079whether the arguments are unsigned or not.</p>
2080<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2081<pre> &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2082</pre>
2083</div>
2084<!-- _______________________________________________________________________ -->
2085<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2086</a> </div>
2087<div class="doc_text">
2088<h5>Syntax:</h5>
2089<pre> &lt;result&gt; = sdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2090</pre>
2091<h5>Overview:</h5>
2092<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2093operands.</p>
2094<h5>Arguments:</h5>
2095<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2096<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2097types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2098of the values in which case the elements must be integers.</p>
2099<h5>Semantics:</h5>
2100<p>The value produced is the signed integer quotient of the two operands. This
2101instruction always performs a signed division operation, regardless of whether
2102the arguments are signed or not.</p>
2103<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2104<pre> &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2105</pre>
2106</div>
2107<!-- _______________________________________________________________________ -->
2108<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2109Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2110<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2111<h5>Syntax:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2112<pre> &lt;result&gt; = fdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2113</pre>
2114<h5>Overview:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2115<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2116operands.</p>
2117<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2118<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2119<a href="#t_floating">floating point</a> values. Both arguments must have
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2120identical types. This instruction can also take <a href="#t_vector">vector</a>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2121versions of floating point values.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2122<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2123<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2124<h5>Example:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2125<pre> &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]2126</pre>
2127</div>
2128<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2129<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2130</div>
2131<div class="doc_text">
2132<h5>Syntax:</h5>
2133<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2134</pre>
2135<h5>Overview:</h5>
2136<p>The '<tt>urem</tt>' instruction returns the remainder from the
2137unsigned division of its two arguments.</p>
2138<h5>Arguments:</h5>
2139<p>The two arguments to the '<tt>urem</tt>' instruction must be
2140<a href="#t_integer">integer</a> values. Both arguments must have identical
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2141types. This instruction can also take <a href="#t_vector">vector</a> versions
2142of the values in which case the elements must be integers.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2143<h5>Semantics:</h5>
2144<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
2145This instruction always performs an unsigned division to get the remainder,
2146regardless of whether the arguments are unsigned or not.</p>
2147<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2148<pre> &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2149</pre>
2150
2151</div>
2152<!-- _______________________________________________________________________ -->
2153<div class="doc_subsubsection"> <a name="i_srem">'<tt>srem</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2154Instruction</a> </div>
2155<div class="doc_text">
2156<h5>Syntax:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2157<pre> &lt;result&gt; = srem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2158</pre>
2159<h5>Overview:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2160<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2161signed division of its two operands. This instruction can also take
2162<a href="#t_vector">vector</a> versions of the values in which case
2163the elements must be integers.</p>
2164</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2165<h5>Arguments:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2166<p>The two arguments to the '<tt>srem</tt>' instruction must be
2167<a href="#t_integer">integer</a> values. Both arguments must have identical
2168types.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2169<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2170<p>This instruction returns the <i>remainder</i> of a division (where the result
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2171has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
2172operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
2173a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2174 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2175Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2176please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2177Wikipedia: modulo operation</a>.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2178<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2179<pre> &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2180</pre>
2181
2182</div>
2183<!-- _______________________________________________________________________ -->
2184<div class="doc_subsubsection"> <a name="i_frem">'<tt>frem</tt>'
2185Instruction</a> </div>
2186<div class="doc_text">
2187<h5>Syntax:</h5>
2188<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2189</pre>
2190<h5>Overview:</h5>
2191<p>The '<tt>frem</tt>' instruction returns the remainder from the
2192division of its two operands.</p>
2193<h5>Arguments:</h5>
2194<p>The two arguments to the '<tt>frem</tt>' instruction must be
2195<a href="#t_floating">floating point</a> values. Both arguments must have
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2196identical types. This instruction can also take <a href="#t_vector">vector</a>
2197versions of floating point values.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2198<h5>Semantics:</h5>
2199<p>This instruction returns the <i>remainder</i> of a division.</p>
2200<h5>Example:</h5>
2201<pre> &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]2202</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2203</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2204
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2205<!-- ======================================================================= -->
2206<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2207Operations</a> </div>
2208<div class="doc_text">
2209<p>Bitwise binary operators are used to do various forms of
2210bit-twiddling in a program. They are generally very efficient
2211instructions and can commonly be strength reduced from other
2212instructions. They require two operands, execute an operation on them,
2213and produce a single value. The resulting value of the bitwise binary
2214operators is always the same type as its first operand.</p>
2215</div>
2216
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2217<!-- _______________________________________________________________________ -->
2218<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2219Instruction</a> </div>
2220<div class="doc_text">
2221<h5>Syntax:</h5>
2222<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2223</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2224
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2225<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2226
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2227<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2228the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2229
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2230<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2231
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2232<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
2233 href="#t_integer">integer</a> type.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2234
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2235<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2236
2237<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup>. If
2238<tt>var2</tt> is (statically or dynamically) equal to or larger than the number
2239of bits in <tt>var1</tt>, the result is undefined.</p>
2240
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2241<h5>Example:</h5><pre>
2242 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2243 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2244 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2245 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2246</pre>
2247</div>
2248<!-- _______________________________________________________________________ -->
2249<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2250Instruction</a> </div>
2251<div class="doc_text">
2252<h5>Syntax:</h5>
2253<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2254</pre>
2255
2256<h5>Overview:</h5>
2257<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2258operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2259
2260<h5>Arguments:</h5>
2261<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
2262<a href="#t_integer">integer</a> type.</p>
2263
2264<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2265
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2266<p>This instruction always performs a logical shift right operation. The most
2267significant bits of the result will be filled with zero bits after the
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2268shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
2269the number of bits in <tt>var1</tt>, the result is undefined.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2270
2271<h5>Example:</h5>
2272<pre>
2273 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2274 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2275 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2276 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2277 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2278</pre>
2279</div>
2280
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2281<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2282<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2283Instruction</a> </div>
2284<div class="doc_text">
2285
2286<h5>Syntax:</h5>
2287<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2288</pre>
2289
2290<h5>Overview:</h5>
2291<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2292operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2293
2294<h5>Arguments:</h5>
2295<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
2296<a href="#t_integer">integer</a> type.</p>
2297
2298<h5>Semantics:</h5>
2299<p>This instruction always performs an arithmetic shift right operation,
2300The most significant bits of the result will be filled with the sign bit
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2301of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
2302larger than the number of bits in <tt>var1</tt>, the result is undefined.
2303</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2304
2305<h5>Example:</h5>
2306<pre>
2307 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2308 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2309 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2310 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2311 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2312</pre>
2313</div>
2314
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2315<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2316<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2317Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2318<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2319<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2320<pre> &lt;result&gt; = and &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2321</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2322<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2323<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2324its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2325<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2326<p>The two arguments to the '<tt>and</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2327 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2328identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2329<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2330<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2331<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2332<div style="align: center">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2333<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2334 <tbody>
2335 <tr>
2336 <td>In0</td>
2337 <td>In1</td>
2338 <td>Out</td>
2339 </tr>
2340 <tr>
2341 <td>0</td>
2342 <td>0</td>
2343 <td>0</td>
2344 </tr>
2345 <tr>
2346 <td>0</td>
2347 <td>1</td>
2348 <td>0</td>
2349 </tr>
2350 <tr>
2351 <td>1</td>
2352 <td>0</td>
2353 <td>0</td>
2354 </tr>
2355 <tr>
2356 <td>1</td>
2357 <td>1</td>
2358 <td>1</td>
2359 </tr>
2360 </tbody>
2361</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2362</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2363<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2364<pre> &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
2365 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2366 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2367</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2368</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2369<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2370<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2371<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2372<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2373<pre> &lt;result&gt; = or &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2374</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2375<h5>Overview:</h5>
2376<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2377or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2378<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2379<p>The two arguments to the '<tt>or</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2380 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2381identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2382<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2383<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2384<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2385<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2386<table border="1" cellspacing="0" cellpadding="4">
2387 <tbody>
2388 <tr>
2389 <td>In0</td>
2390 <td>In1</td>
2391 <td>Out</td>
2392 </tr>
2393 <tr>
2394 <td>0</td>
2395 <td>0</td>
2396 <td>0</td>
2397 </tr>
2398 <tr>
2399 <td>0</td>
2400 <td>1</td>
2401 <td>1</td>
2402 </tr>
2403 <tr>
2404 <td>1</td>
2405 <td>0</td>
2406 <td>1</td>
2407 </tr>
2408 <tr>
2409 <td>1</td>
2410 <td>1</td>
2411 <td>1</td>
2412 </tr>
2413 </tbody>
2414</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2415</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2416<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2417<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2418 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2419 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2420</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2421</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2422<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2423<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2424Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2425<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2426<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2427<pre> &lt;result&gt; = xor &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2428</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2429<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2430<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2431or of its two operands. The <tt>xor</tt> is used to implement the
2432"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2433<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2434<p>The two arguments to the '<tt>xor</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2435 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2436identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2437<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2438<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2439<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2440<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2441<table border="1" cellspacing="0" cellpadding="4">
2442 <tbody>
2443 <tr>
2444 <td>In0</td>
2445 <td>In1</td>
2446 <td>Out</td>
2447 </tr>
2448 <tr>
2449 <td>0</td>
2450 <td>0</td>
2451 <td>0</td>
2452 </tr>
2453 <tr>
2454 <td>0</td>
2455 <td>1</td>
2456 <td>1</td>
2457 </tr>
2458 <tr>
2459 <td>1</td>
2460 <td>0</td>
2461 <td>1</td>
2462 </tr>
2463 <tr>
2464 <td>1</td>
2465 <td>1</td>
2466 <td>0</td>
2467 </tr>
2468 </tbody>
2469</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2470</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2471<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2472<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2473<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2474 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2475 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2476 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2477</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2478</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2479
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2480<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2481<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2482 <a name="vectorops">Vector Operations</a>
2483</div>
2484
2485<div class="doc_text">
2486
2487<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2488target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2489vector-specific operations needed to process vectors effectively. While LLVM
2490does directly support these vector operations, many sophisticated algorithms
2491will want to use target-specific intrinsics to take full advantage of a specific
2492target.</p>
2493
2494</div>
2495
2496<!-- _______________________________________________________________________ -->
2497<div class="doc_subsubsection">
2498 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2499</div>
2500
2501<div class="doc_text">
2502
2503<h5>Syntax:</h5>
2504
2505<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2506 &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]2507</pre>
2508
2509<h5>Overview:</h5>
2510
2511<p>
2512The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2513element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2514</p>
2515
2516
2517<h5>Arguments:</h5>
2518
2519<p>
2520The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2521value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2522an index indicating the position from which to extract the element.
2523The index may be a variable.</p>
2524
2525<h5>Semantics:</h5>
2526
2527<p>
2528The result is a scalar of the same type as the element type of
2529<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2530<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2531results are undefined.
2532</p>
2533
2534<h5>Example:</h5>
2535
2536<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2537 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2538</pre>
2539</div>
2540
2541
2542<!-- _______________________________________________________________________ -->
2543<div class="doc_subsubsection">
2544 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2545</div>
2546
2547<div class="doc_text">
2548
2549<h5>Syntax:</h5>
2550
2551<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2552 &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]2553</pre>
2554
2555<h5>Overview:</h5>
2556
2557<p>
2558The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2559element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2560</p>
2561
2562
2563<h5>Arguments:</h5>
2564
2565<p>
2566The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2567value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2568scalar value whose type must equal the element type of the first
2569operand. The third operand is an index indicating the position at
2570which to insert the value. The index may be a variable.</p>
2571
2572<h5>Semantics:</h5>
2573
2574<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2575The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2576element values are those of <tt>val</tt> except at position
2577<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2578exceeds the length of <tt>val</tt>, the results are undefined.
2579</p>
2580
2581<h5>Example:</h5>
2582
2583<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2584 %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]2585</pre>
2586</div>
2587
2588<!-- _______________________________________________________________________ -->
2589<div class="doc_subsubsection">
2590 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2591</div>
2592
2593<div class="doc_text">
2594
2595<h5>Syntax:</h5>
2596
2597<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2598 &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;n x i32&gt; &lt;mask&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2599</pre>
2600
2601<h5>Overview:</h5>
2602
2603<p>
2604The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2605from two input vectors, returning a vector of the same type.
2606</p>
2607
2608<h5>Arguments:</h5>
2609
2610<p>
2611The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2612with types that match each other and types that match the result of the
2613instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2614of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2615</p>
2616
2617<p>
2618The shuffle mask operand is required to be a constant vector with either
2619constant integer or undef values.
2620</p>
2621
2622<h5>Semantics:</h5>
2623
2624<p>
2625The elements of the two input vectors are numbered from left to right across
2626both of the vectors. The shuffle mask operand specifies, for each element of
2627the result vector, which element of the two input registers the result element
2628gets. The element selector may be undef (meaning "don't care") and the second
2629operand may be undef if performing a shuffle from only one vector.
2630</p>
2631
2632<h5>Example:</h5>
2633
2634<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2635 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2636 &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]2637 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2638 &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.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2639</pre>
2640</div>
2641
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]2642
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2643<!-- ======================================================================= -->
2644<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2645 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2646</div>
2647
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2648<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2649
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2650<p>A key design point of an SSA-based representation is how it
2651represents memory. In LLVM, no memory locations are in SSA form, which
2652makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2653allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2654
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2655</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2656
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2657<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2658<div class="doc_subsubsection">
2659 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
2660</div>
2661
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2662<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2663
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2664<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2665
2666<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2667 &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]2668</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2669
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2670<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2671
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2672<p>The '<tt>malloc</tt>' instruction allocates memory from the system
2673heap and returns a pointer to it.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2674
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2675<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2676
2677<p>The '<tt>malloc</tt>' instruction allocates
2678<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]2679bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2680appropriate type to the program. If "NumElements" is specified, it is the
2681number of elements allocated. If an alignment is specified, the value result
2682of the allocation is guaranteed to be aligned to at least that boundary. If
2683not specified, or if zero, the target can choose to align the allocation on any
2684convenient boundary.</p>
2685
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2686<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2687
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2688<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2689
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2690<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
2691a pointer is returned.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2692
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2693<h5>Example:</h5>
2694
2695<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2696 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2697
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2698 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
2699 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
2700 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
2701 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
2702 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2703</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2704</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2705
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2706<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2707<div class="doc_subsubsection">
2708 <a name="i_free">'<tt>free</tt>' Instruction</a>
2709</div>
2710
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2711<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2712
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2713<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2714
2715<pre>
2716 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2717</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2718
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2719<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2720
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2721<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2722memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2723
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2724<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2725
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2726<p>'<tt>value</tt>' shall be a pointer value that points to a value
2727that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
2728instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2729
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2730<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2731
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2732<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2733after this instruction executes.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2734
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2735<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2736
2737<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2738 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
2739 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2740</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2741</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2742
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2743<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2744<div class="doc_subsubsection">
2745 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
2746</div>
2747
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2748<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2749
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2750<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2751
2752<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2753 &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]2754</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2755
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2756<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2757
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2758<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
2759currently executing function, to be automatically released when this function
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2760returns to its caller.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2761
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2762<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2763
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2764<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2765bytes of memory on the runtime stack, returning a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2766appropriate type to the program. If "NumElements" is specified, it is the
2767number of elements allocated. If an alignment is specified, the value result
2768of the allocation is guaranteed to be aligned to at least that boundary. If
2769not specified, or if zero, the target can choose to align the allocation on any
2770convenient boundary.</p>
2771
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2772<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2773
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2774<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2775
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2776<p>Memory is allocated; a pointer is returned. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2777memory is automatically released when the function returns. The '<tt>alloca</tt>'
2778instruction is commonly used to represent automatic variables that must
2779have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]2780 href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2781instructions), the memory is reclaimed.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2782
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2783<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2784
2785<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2786 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2787 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
2788 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2789 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2790</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2791</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2792
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2793<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2794<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
2795Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2796<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2797<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2798<pre> &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br> &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br></pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2799<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2800<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2801<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2802<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2803address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]2804 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2805marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2806the number or order of execution of this <tt>load</tt> with other
2807volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
2808instructions. </p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2809<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2810<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2811<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2812<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2813 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2814 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
2815 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2816</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2817</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2818<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2819<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
2820Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]2821<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2822<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2823<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
2824 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]2825</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2826<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2827<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2828<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2829<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2830to store and an address at which to store it. The type of the '<tt>&lt;pointer&gt;</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2831operand must be a pointer to the type of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2832operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2833optimizer is not allowed to modify the number or order of execution of
2834this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
2835 href="#i_store">store</a></tt> instructions.</p>
2836<h5>Semantics:</h5>
2837<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
2838at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2839<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2840<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]2841 store i32 3, i32* %ptr <i>; yields {void}</i>
2842 %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]2843</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2844</div>
2845
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2846<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2847<div class="doc_subsubsection">
2848 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
2849</div>
2850
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2851<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2852<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2853<pre>
2854 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
2855</pre>
2856
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2857<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2858
2859<p>
2860The '<tt>getelementptr</tt>' instruction is used to get the address of a
2861subelement of an aggregate data structure.</p>
2862
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2863<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2864
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2865<p>This instruction takes a list of integer operands that indicate what
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2866elements of the aggregate object to index to. The actual types of the arguments
2867provided depend on the type of the first pointer argument. The
2868'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]2869levels of a structure or to a specific index in an array. When indexing into a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2870structure, only <tt>i32</tt> integer constants are allowed. When indexing
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2871into an array or pointer, only integers of 32 or 64 bits are allowed, and will
2872be sign extended to 64-bit values.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2873
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2874<p>For example, let's consider a C code fragment and how it gets
2875compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2876
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2877<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2878<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2879struct RT {
2880 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2881 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2882 char C;
2883};
2884struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2885 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2886 double Y;
2887 struct RT Z;
2888};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2889
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2890int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2891 return &amp;s[1].Z.B[5][13];
2892}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2893</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2894</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2895
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2896<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2897
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2898<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2899<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2900%RT = type { i8 , [10 x [20 x i32]], i8 }
2901%ST = type { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2902
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2903define i32* %foo(%ST* %s) {
2904entry:
2905 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
2906 ret i32* %reg
2907}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2908</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2909</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2910
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2911<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2912
2913<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2914on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2915and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
Reid Spencer42ddd842006-12-03 16:53:48 +0000[diff] [blame]2916<a href="#t_integer">integer</a> type but the value will always be sign extended
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2917to 64-bits. <a href="#t_struct">Structure</a> types require <tt>i32</tt>
Reid Spencer42ddd842006-12-03 16:53:48 +0000[diff] [blame]2918<b>constants</b>.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2919
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2920<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2921type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2922}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2923the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
2924i8 }</tt>' type, another structure. The third index indexes into the second
2925element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2926array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2927'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
2928to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2929
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2930<p>Note that it is perfectly legal to index partially through a
2931structure, returning a pointer to an inner element. Because of this,
2932the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2933
2934<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2935 define i32* %foo(%ST* %s) {
2936 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2937 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
2938 %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]2939 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
2940 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
2941 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2942 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2943</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2944
2945<p>Note that it is undefined to access an array out of bounds: array and
2946pointer indexes must always be within the defined bounds of the array type.
2947The one exception for this rules is zero length arrays. These arrays are
2948defined to be accessible as variable length arrays, which requires access
2949beyond the zero'th element.</p>
2950
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2951<p>The getelementptr instruction is often confusing. For some more insight
2952into how it works, see <a href="GetElementPtr.html">the getelementptr
2953FAQ</a>.</p>
2954
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2955<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2956
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2957<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2958 <i>; yields [12 x i8]*:aptr</i>
2959 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2960</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2961</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2962
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2963<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]2964<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2965</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2966<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]2967<p>The instructions in this category are the conversion instructions (casting)
2968which all take a single operand and a type. They perform various bit conversions
2969on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2970</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]2971
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2972<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]2973<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2974 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
2975</div>
2976<div class="doc_text">
2977
2978<h5>Syntax:</h5>
2979<pre>
2980 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2981</pre>
2982
2983<h5>Overview:</h5>
2984<p>
2985The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
2986</p>
2987
2988<h5>Arguments:</h5>
2989<p>
2990The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
2991be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2992and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2993type. The bit size of <tt>value</tt> must be larger than the bit size of
2994<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2995
2996<h5>Semantics:</h5>
2997<p>
2998The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2999and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3000larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3001It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3002
3003<h5>Example:</h5>
3004<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3005 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3006 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3007 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3008</pre>
3009</div>
3010
3011<!-- _______________________________________________________________________ -->
3012<div class="doc_subsubsection">
3013 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3014</div>
3015<div class="doc_text">
3016
3017<h5>Syntax:</h5>
3018<pre>
3019 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3020</pre>
3021
3022<h5>Overview:</h5>
3023<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3024<tt>ty2</tt>.</p>
3025
3026
3027<h5>Arguments:</h5>
3028<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3029<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3030also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3031<tt>value</tt> must be smaller than the bit size of the destination type,
3032<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3033
3034<h5>Semantics:</h5>
3035<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattnerd1d25172007-05-24 19:13:27 +0000[diff] [blame]3036bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3037
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3038<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]3039
3040<h5>Example:</h5>
3041<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3042 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3043 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3044</pre>
3045</div>
3046
3047<!-- _______________________________________________________________________ -->
3048<div class="doc_subsubsection">
3049 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3050</div>
3051<div class="doc_text">
3052
3053<h5>Syntax:</h5>
3054<pre>
3055 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3056</pre>
3057
3058<h5>Overview:</h5>
3059<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3060
3061<h5>Arguments:</h5>
3062<p>
3063The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3064<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3065also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3066<tt>value</tt> must be smaller than the bit size of the destination type,
3067<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3068
3069<h5>Semantics:</h5>
3070<p>
3071The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3072bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattnerd1d25172007-05-24 19:13:27 +0000[diff] [blame]3073the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3074
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3075<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]3076
3077<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3078<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3079 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3080 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3081</pre>
3082</div>
3083
3084<!-- _______________________________________________________________________ -->
3085<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3086 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3087</div>
3088
3089<div class="doc_text">
3090
3091<h5>Syntax:</h5>
3092
3093<pre>
3094 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3095</pre>
3096
3097<h5>Overview:</h5>
3098<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3099<tt>ty2</tt>.</p>
3100
3101
3102<h5>Arguments:</h5>
3103<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3104 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3105cast it to. The size of <tt>value</tt> must be larger than the size of
3106<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3107<i>no-op cast</i>.</p>
3108
3109<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3110<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3111<a href="#t_floating">floating point</a> type to a smaller
3112<a href="#t_floating">floating point</a> type. If the value cannot fit within
3113the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3114
3115<h5>Example:</h5>
3116<pre>
3117 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3118 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3119</pre>
3120</div>
3121
3122<!-- _______________________________________________________________________ -->
3123<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3124 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3125</div>
3126<div class="doc_text">
3127
3128<h5>Syntax:</h5>
3129<pre>
3130 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3131</pre>
3132
3133<h5>Overview:</h5>
3134<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3135floating point value.</p>
3136
3137<h5>Arguments:</h5>
3138<p>The '<tt>fpext</tt>' instruction takes a
3139<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3140and a <a href="#t_floating">floating point</a> type to cast it to. The source
3141type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3142
3143<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3144<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3145<a href="#t_floating">floating point</a> type to a larger
3146<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3147used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3148<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]3149
3150<h5>Example:</h5>
3151<pre>
3152 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3153 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3154</pre>
3155</div>
3156
3157<!-- _______________________________________________________________________ -->
3158<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3159 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3160</div>
3161<div class="doc_text">
3162
3163<h5>Syntax:</h5>
3164<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3165 &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]3166</pre>
3167
3168<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3169<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3170unsigned integer equivalent of type <tt>ty2</tt>.
3171</p>
3172
3173<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3174<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3175scalar or vector <a href="#t_floating">floating point</a> value, and a type
3176to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3177type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3178vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3179
3180<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3181<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3182<a href="#t_floating">floating point</a> operand into the nearest (rounding
3183towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3184the results are undefined.</p>
3185
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3186<h5>Example:</h5>
3187<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3188 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3189 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3190 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3191</pre>
3192</div>
3193
3194<!-- _______________________________________________________________________ -->
3195<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3196 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3197</div>
3198<div class="doc_text">
3199
3200<h5>Syntax:</h5>
3201<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3202 &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]3203</pre>
3204
3205<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3206<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3207<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3208</p>
3209
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3210<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3211<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3212scalar or vector <a href="#t_floating">floating point</a> value, and a type
3213to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3214type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3215vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3216
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3217<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3218<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3219<a href="#t_floating">floating point</a> operand into the nearest (rounding
3220towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3221the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3222
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3223<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3224<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3225 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3226 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3227 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3228</pre>
3229</div>
3230
3231<!-- _______________________________________________________________________ -->
3232<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3233 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3234</div>
3235<div class="doc_text">
3236
3237<h5>Syntax:</h5>
3238<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3239 &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]3240</pre>
3241
3242<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3243<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3244integer and converts that value to the <tt>ty2</tt> type.</p>
3245
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3246<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3247<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3248scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3249to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3250type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3251floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3252
3253<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3254<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3255integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3256the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3257
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3258<h5>Example:</h5>
3259<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3260 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3261 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3262</pre>
3263</div>
3264
3265<!-- _______________________________________________________________________ -->
3266<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3267 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3268</div>
3269<div class="doc_text">
3270
3271<h5>Syntax:</h5>
3272<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3273 &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]3274</pre>
3275
3276<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3277<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3278integer and converts that value to the <tt>ty2</tt> type.</p>
3279
3280<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3281<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3282scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3283to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3284type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3285floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3286
3287<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3288<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3289integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3290the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3291
3292<h5>Example:</h5>
3293<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3294 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3295 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3296</pre>
3297</div>
3298
3299<!-- _______________________________________________________________________ -->
3300<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3301 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3302</div>
3303<div class="doc_text">
3304
3305<h5>Syntax:</h5>
3306<pre>
3307 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3308</pre>
3309
3310<h5>Overview:</h5>
3311<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3312the integer type <tt>ty2</tt>.</p>
3313
3314<h5>Arguments:</h5>
3315<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3316must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3317<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3318
3319<h5>Semantics:</h5>
3320<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3321<tt>ty2</tt> by interpreting the pointer value as an integer and either
3322truncating or zero extending that value to the size of the integer type. If
3323<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3324<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3325are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3326change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3327
3328<h5>Example:</h5>
3329<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3330 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3331 %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]3332</pre>
3333</div>
3334
3335<!-- _______________________________________________________________________ -->
3336<div class="doc_subsubsection">
3337 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3338</div>
3339<div class="doc_text">
3340
3341<h5>Syntax:</h5>
3342<pre>
3343 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3344</pre>
3345
3346<h5>Overview:</h5>
3347<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3348a pointer type, <tt>ty2</tt>.</p>
3349
3350<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3351<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3352value to cast, and a type to cast it to, which must be a
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]3353<a href="#t_pointer">pointer</a> type.
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3354
3355<h5>Semantics:</h5>
3356<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3357<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3358the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3359size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3360the size of a pointer then a zero extension is done. If they are the same size,
3361nothing is done (<i>no-op cast</i>).</p>
3362
3363<h5>Example:</h5>
3364<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3365 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3366 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3367 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3368</pre>
3369</div>
3370
3371<!-- _______________________________________________________________________ -->
3372<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3373 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3374</div>
3375<div class="doc_text">
3376
3377<h5>Syntax:</h5>
3378<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3379 &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]3380</pre>
3381
3382<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3383<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3384<tt>ty2</tt> without changing any bits.</p>
3385
3386<h5>Arguments:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3387<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3388a first class value, and a type to cast it to, which must also be a <a
3389 href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]3390and the destination type, <tt>ty2</tt>, must be identical. If the source
3391type is a pointer, the destination type must also be a pointer.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3392
3393<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3394<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3395<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3396this conversion. The conversion is done as if the <tt>value</tt> had been
3397stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3398converted to other pointer types with this instruction. To convert pointers to
3399other types, use the <a href="#i_inttoptr">inttoptr</a> or
3400<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3401
3402<h5>Example:</h5>
3403<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3404 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3405 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3406 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3407</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3408</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3409
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3410<!-- ======================================================================= -->
3411<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3412<div class="doc_text">
3413<p>The instructions in this category are the "miscellaneous"
3414instructions, which defy better classification.</p>
3415</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3416
3417<!-- _______________________________________________________________________ -->
3418<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3419</div>
3420<div class="doc_text">
3421<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3422<pre> &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {i1}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3423</pre>
3424<h5>Overview:</h5>
3425<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
3426of its two integer operands.</p>
3427<h5>Arguments:</h5>
3428<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3429the condition code indicating the kind of comparison to perform. It is not
3430a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3431<ol>
3432 <li><tt>eq</tt>: equal</li>
3433 <li><tt>ne</tt>: not equal </li>
3434 <li><tt>ugt</tt>: unsigned greater than</li>
3435 <li><tt>uge</tt>: unsigned greater or equal</li>
3436 <li><tt>ult</tt>: unsigned less than</li>
3437 <li><tt>ule</tt>: unsigned less or equal</li>
3438 <li><tt>sgt</tt>: signed greater than</li>
3439 <li><tt>sge</tt>: signed greater or equal</li>
3440 <li><tt>slt</tt>: signed less than</li>
3441 <li><tt>sle</tt>: signed less or equal</li>
3442</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3443<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3444<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3445<h5>Semantics:</h5>
3446<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3447the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3448yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3449<ol>
3450 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3451 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3452 </li>
3453 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3454 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3455 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
3456 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3457 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
3458 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3459 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
3460 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3461 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
3462 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
3463 <li><tt>sgt</tt>: interprets the operands as signed values and yields
3464 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3465 <li><tt>sge</tt>: interprets the operands as signed values and yields
3466 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3467 <li><tt>slt</tt>: interprets the operands as signed values and yields
3468 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3469 <li><tt>sle</tt>: interprets the operands as signed values and yields
3470 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3471</ol>
3472<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3473values are compared as if they were integers.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3474
3475<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3476<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3477 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3478 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3479 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3480 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3481 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3482</pre>
3483</div>
3484
3485<!-- _______________________________________________________________________ -->
3486<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3487</div>
3488<div class="doc_text">
3489<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3490<pre> &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {i1}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3491</pre>
3492<h5>Overview:</h5>
3493<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
3494of its floating point operands.</p>
3495<h5>Arguments:</h5>
3496<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3497the condition code indicating the kind of comparison to perform. It is not
3498a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3499<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3500 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3501 <li><tt>oeq</tt>: ordered and equal</li>
3502 <li><tt>ogt</tt>: ordered and greater than </li>
3503 <li><tt>oge</tt>: ordered and greater than or equal</li>
3504 <li><tt>olt</tt>: ordered and less than </li>
3505 <li><tt>ole</tt>: ordered and less than or equal</li>
3506 <li><tt>one</tt>: ordered and not equal</li>
3507 <li><tt>ord</tt>: ordered (no nans)</li>
3508 <li><tt>ueq</tt>: unordered or equal</li>
3509 <li><tt>ugt</tt>: unordered or greater than </li>
3510 <li><tt>uge</tt>: unordered or greater than or equal</li>
3511 <li><tt>ult</tt>: unordered or less than </li>
3512 <li><tt>ule</tt>: unordered or less than or equal</li>
3513 <li><tt>une</tt>: unordered or not equal</li>
3514 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3515 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3516</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3517<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]3518<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3519<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
3520<a href="#t_floating">floating point</a> typed. They must have identical
3521types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3522<h5>Semantics:</h5>
3523<p>The '<tt>fcmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3524the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3525yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3526<ol>
3527 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3528 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3529 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3530 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3531 <tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3532 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3533 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3534 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3535 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3536 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3537 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3538 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3539 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3540 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3541 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3542 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3543 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3544 <tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3545 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3546 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3547 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3548 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3549 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3550 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3551 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3552 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3553 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3554 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
3555</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3556
3557<h5>Example:</h5>
3558<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
3559 &lt;result&gt; = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
3560 &lt;result&gt; = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
3561 &lt;result&gt; = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
3562</pre>
3563</div>
3564
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3565<!-- _______________________________________________________________________ -->
3566<div class="doc_subsubsection"> <a name="i_phi">'<tt>phi</tt>'
3567Instruction</a> </div>
3568<div class="doc_text">
3569<h5>Syntax:</h5>
3570<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
3571<h5>Overview:</h5>
3572<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
3573the SSA graph representing the function.</p>
3574<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3575<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3576field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
3577as arguments, with one pair for each predecessor basic block of the
3578current block. Only values of <a href="#t_firstclass">first class</a>
3579type may be used as the value arguments to the PHI node. Only labels
3580may be used as the label arguments.</p>
3581<p>There must be no non-phi instructions between the start of a basic
3582block and the PHI instructions: i.e. PHI instructions must be first in
3583a basic block.</p>
3584<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3585<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
3586specified by the pair corresponding to the predecessor basic block that executed
3587just prior to the current block.</p>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3588<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3589<pre>Loop: ; Infinite loop that counts from 0 on up...<br> %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]<br> %nextindvar = add i32 %indvar, 1<br> br label %Loop<br></pre>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3590</div>
3591
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3592<!-- _______________________________________________________________________ -->
3593<div class="doc_subsubsection">
3594 <a name="i_select">'<tt>select</tt>' Instruction</a>
3595</div>
3596
3597<div class="doc_text">
3598
3599<h5>Syntax:</h5>
3600
3601<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3602 &lt;result&gt; = select i1 &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3603</pre>
3604
3605<h5>Overview:</h5>
3606
3607<p>
3608The '<tt>select</tt>' instruction is used to choose one value based on a
3609condition, without branching.
3610</p>
3611
3612
3613<h5>Arguments:</h5>
3614
3615<p>
3616The '<tt>select</tt>' instruction requires a boolean value indicating the condition, and two values of the same <a href="#t_firstclass">first class</a> type.
3617</p>
3618
3619<h5>Semantics:</h5>
3620
3621<p>
3622If the boolean condition evaluates to true, the instruction returns the first
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3623value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3624</p>
3625
3626<h5>Example:</h5>
3627
3628<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3629 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3630</pre>
3631</div>
3632
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]3633
3634<!-- _______________________________________________________________________ -->
3635<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3636 <a name="i_call">'<tt>call</tt>' Instruction</a>
3637</div>
3638
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3639<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3640
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3641<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3642<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3643 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;param list&gt;)
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3644</pre>
3645
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3646<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3647
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3648<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3649
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3650<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3651
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3652<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3653
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3654<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3655 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3656 <p>The optional "tail" marker indicates whether the callee function accesses
3657 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3658 function call is eligible for tail call optimization. Note that calls may
3659 be marked "tail" even if they do not occur before a <a
3660 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3661 </li>
3662 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3663 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3664 convention</a> the call should use. If none is specified, the call defaults
3665 to using C calling conventions.
3666 </li>
3667 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3668 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
3669 the type of the return value. Functions that return no value are marked
3670 <tt><a href="#t_void">void</a></tt>.</p>
3671 </li>
3672 <li>
3673 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
3674 value being invoked. The argument types must match the types implied by
3675 this signature. This type can be omitted if the function is not varargs
3676 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3677 </li>
3678 <li>
3679 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
3680 be invoked. In most cases, this is a direct function invocation, but
3681 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3682 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3683 </li>
3684 <li>
3685 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]3686 function signature argument types. All arguments must be of
3687 <a href="#t_firstclass">first class</a> type. If the function signature
3688 indicates the function accepts a variable number of arguments, the extra
3689 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3690 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3691</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3692
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3693<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3694
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3695<p>The '<tt>call</tt>' instruction is used to cause control flow to
3696transfer to a specified function, with its incoming arguments bound to
3697the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
3698instruction in the called function, control flow continues with the
3699instruction after the function call, and the return value of the
3700function is bound to the result argument. This is a simpler case of
3701the <a href="#i_invoke">invoke</a> instruction.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3702
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3703<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3704
3705<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3706 %retval = call i32 @test(i32 %argc)
3707 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42);
3708 %X = tail call i32 @foo()
3709 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo()
3710 %Z = call void %foo(i8 97 signext)
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3711</pre>
3712
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3713</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3714
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3715<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3716<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3717 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3718</div>
3719
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3720<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3721
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3722<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3723
3724<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3725 &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]3726</pre>
3727
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3728<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3729
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3730<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3731the "variable argument" area of a function call. It is used to implement the
3732<tt>va_arg</tt> macro in C.</p>
3733
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3734<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3735
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3736<p>This instruction takes a <tt>va_list*</tt> value and the type of
3737the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3738increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3739actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3740
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3741<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3742
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3743<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
3744type from the specified <tt>va_list</tt> and causes the
3745<tt>va_list</tt> to point to the next argument. For more information,
3746see the variable argument handling <a href="#int_varargs">Intrinsic
3747Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3748
3749<p>It is legal for this instruction to be called in a function which does not
3750take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3751function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3752
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3753<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3754href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3755argument.</p>
3756
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3757<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3758
3759<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
3760
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3761</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3762
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3763<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3764<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
3765<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3766
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3767<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3768
3769<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3770well known names and semantics and are required to follow certain restrictions.
3771Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3772language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]3773adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3774
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3775<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3776prefix is reserved in LLVM for intrinsic names; thus, function names may not
3777begin with this prefix. Intrinsic functions must always be external functions:
3778you cannot define the body of intrinsic functions. Intrinsic functions may
3779only be used in call or invoke instructions: it is illegal to take the address
3780of an intrinsic function. Additionally, because intrinsic functions are part
3781of the LLVM language, it is required if any are added that they be documented
3782here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3783
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]3784<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
3785a family of functions that perform the same operation but on different data
3786types. Because LLVM can represent over 8 million different integer types,
3787overloading is used commonly to allow an intrinsic function to operate on any
3788integer type. One or more of the argument types or the result type can be
3789overloaded to accept any integer type. Argument types may also be defined as
3790exactly matching a previous argument's type or the result type. This allows an
3791intrinsic function which accepts multiple arguments, but needs all of them to
3792be of the same type, to only be overloaded with respect to a single argument or
3793the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3794
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]3795<p>Overloaded intrinsics will have the names of its overloaded argument types
3796encoded into its function name, each preceded by a period. Only those types
3797which are overloaded result in a name suffix. Arguments whose type is matched
3798against another type do not. For example, the <tt>llvm.ctpop</tt> function can
3799take an integer of any width and returns an integer of exactly the same integer
3800width. This leads to a family of functions such as
3801<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
3802Only one type, the return type, is overloaded, and only one type suffix is
3803required. Because the argument's type is matched against the return type, it
3804does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3805
3806<p>To learn how to add an intrinsic function, please see the
3807<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3808</p>
3809
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3810</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3811
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3812<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3813<div class="doc_subsection">
3814 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
3815</div>
3816
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3817<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3818
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3819<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3820 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3821intrinsic functions. These functions are related to the similarly
3822named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3823
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3824<p>All of these functions operate on arguments that use a
3825target-specific value type "<tt>va_list</tt>". The LLVM assembly
3826language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3827transformations should be prepared to handle these functions regardless of
3828the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3829
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]3830<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3831instruction and the variable argument handling intrinsic functions are
3832used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3833
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3834<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3835<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3836define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3837 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3838 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3839 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3840 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3841
3842 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3843 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3844
3845 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3846 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3847 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3848 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3849 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3850
3851 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3852 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3853 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3854}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3855
3856declare void @llvm.va_start(i8*)
3857declare void @llvm.va_copy(i8*, i8*)
3858declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3859</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3860</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3861
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3862</div>
3863
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3864<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3865<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3866 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3867</div>
3868
3869
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3870<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3871<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3872<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3873<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3874<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
3875<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
3876href="#i_va_arg">va_arg</a></tt>.</p>
3877
3878<h5>Arguments:</h5>
3879
3880<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
3881
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3882<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3883
3884<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
3885macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3886<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3887<tt>va_arg</tt> will produce the first variable argument passed to the function.
3888Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3889last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3890
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3891</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3892
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3893<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3894<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3895 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3896</div>
3897
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3898<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3899<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3900<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3901<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3902
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3903<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3904which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3905or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3906
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3907<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3908
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3909<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]3910
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3911<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3912
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3913<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3914macro available in C. In a target-dependent way, it destroys the
3915<tt>va_list</tt> element to which the argument points. Calls to <a
3916href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
3917<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
3918<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3919
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3920</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3921
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3922<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3923<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3924 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3925</div>
3926
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3927<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3928
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3929<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3930
3931<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3932 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3933</pre>
3934
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3935<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3936
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3937<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
3938from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3939
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3940<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3941
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3942<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharthd0a4c622005-06-22 20:38:11 +0000[diff] [blame]3943The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3944
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3945
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3946<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3947
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3948<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
3949macro available in C. In a target-dependent way, it copies the source
3950<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
3951intrinsic is necessary because the <tt><a href="#int_va_start">
3952llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
3953example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3954
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3955</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3956
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3957<!-- ======================================================================= -->
3958<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3959 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
3960</div>
3961
3962<div class="doc_text">
3963
3964<p>
3965LLVM support for <a href="GarbageCollection.html">Accurate Garbage
3966Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3967These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3968stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3969href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3970Front-ends for type-safe garbage collected languages should generate these
3971intrinsics to make use of the LLVM garbage collectors. For more details, see <a
3972href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
3973</p>
3974</div>
3975
3976<!-- _______________________________________________________________________ -->
3977<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3978 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3979</div>
3980
3981<div class="doc_text">
3982
3983<h5>Syntax:</h5>
3984
3985<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]3986 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3987</pre>
3988
3989<h5>Overview:</h5>
3990
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3991<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3992the code generator, and allows some metadata to be associated with it.</p>
3993
3994<h5>Arguments:</h5>
3995
3996<p>The first argument specifies the address of a stack object that contains the
3997root pointer. The second pointer (which must be either a constant or a global
3998value address) contains the meta-data to be associated with the root.</p>
3999
4000<h5>Semantics:</h5>
4001
4002<p>At runtime, a call to this intrinsics stores a null pointer into the "ptrloc"
4003location. At compile-time, the code generator generates information to allow
4004the runtime to find the pointer at GC safe points.
4005</p>
4006
4007</div>
4008
4009
4010<!-- _______________________________________________________________________ -->
4011<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4012 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4013</div>
4014
4015<div class="doc_text">
4016
4017<h5>Syntax:</h5>
4018
4019<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4020 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4021</pre>
4022
4023<h5>Overview:</h5>
4024
4025<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4026locations, allowing garbage collector implementations that require read
4027barriers.</p>
4028
4029<h5>Arguments:</h5>
4030
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4031<p>The second argument is the address to read from, which should be an address
4032allocated from the garbage collector. The first object is a pointer to the
4033start of the referenced object, if needed by the language runtime (otherwise
4034null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4035
4036<h5>Semantics:</h5>
4037
4038<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4039instruction, but may be replaced with substantially more complex code by the
4040garbage collector runtime, as needed.</p>
4041
4042</div>
4043
4044
4045<!-- _______________________________________________________________________ -->
4046<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4047 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4048</div>
4049
4050<div class="doc_text">
4051
4052<h5>Syntax:</h5>
4053
4054<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4055 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4056</pre>
4057
4058<h5>Overview:</h5>
4059
4060<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4061locations, allowing garbage collector implementations that require write
4062barriers (such as generational or reference counting collectors).</p>
4063
4064<h5>Arguments:</h5>
4065
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4066<p>The first argument is the reference to store, the second is the start of the
4067object to store it to, and the third is the address of the field of Obj to
4068store to. If the runtime does not require a pointer to the object, Obj may be
4069null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4070
4071<h5>Semantics:</h5>
4072
4073<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4074instruction, but may be replaced with substantially more complex code by the
4075garbage collector runtime, as needed.</p>
4076
4077</div>
4078
4079
4080
4081<!-- ======================================================================= -->
4082<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4083 <a name="int_codegen">Code Generator Intrinsics</a>
4084</div>
4085
4086<div class="doc_text">
4087<p>
4088These intrinsics are provided by LLVM to expose special features that may only
4089be implemented with code generator support.
4090</p>
4091
4092</div>
4093
4094<!-- _______________________________________________________________________ -->
4095<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4096 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4097</div>
4098
4099<div class="doc_text">
4100
4101<h5>Syntax:</h5>
4102<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4103 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4104</pre>
4105
4106<h5>Overview:</h5>
4107
4108<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4109The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4110target-specific value indicating the return address of the current function
4111or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4112</p>
4113
4114<h5>Arguments:</h5>
4115
4116<p>
4117The argument to this intrinsic indicates which function to return the address
4118for. Zero indicates the calling function, one indicates its caller, etc. The
4119argument is <b>required</b> to be a constant integer value.
4120</p>
4121
4122<h5>Semantics:</h5>
4123
4124<p>
4125The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4126the return address of the specified call frame, or zero if it cannot be
4127identified. The value returned by this intrinsic is likely to be incorrect or 0
4128for arguments other than zero, so it should only be used for debugging purposes.
4129</p>
4130
4131<p>
4132Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4133aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4134source-language caller.
4135</p>
4136</div>
4137
4138
4139<!-- _______________________________________________________________________ -->
4140<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4141 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4142</div>
4143
4144<div class="doc_text">
4145
4146<h5>Syntax:</h5>
4147<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4148 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4149</pre>
4150
4151<h5>Overview:</h5>
4152
4153<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4154The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4155target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4156</p>
4157
4158<h5>Arguments:</h5>
4159
4160<p>
4161The argument to this intrinsic indicates which function to return the frame
4162pointer for. Zero indicates the calling function, one indicates its caller,
4163etc. The argument is <b>required</b> to be a constant integer value.
4164</p>
4165
4166<h5>Semantics:</h5>
4167
4168<p>
4169The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4170the frame address of the specified call frame, or zero if it cannot be
4171identified. The value returned by this intrinsic is likely to be incorrect or 0
4172for arguments other than zero, so it should only be used for debugging purposes.
4173</p>
4174
4175<p>
4176Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4177aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4178source-language caller.
4179</p>
4180</div>
4181
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4182<!-- _______________________________________________________________________ -->
4183<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4184 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4185</div>
4186
4187<div class="doc_text">
4188
4189<h5>Syntax:</h5>
4190<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4191 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4192</pre>
4193
4194<h5>Overview:</h5>
4195
4196<p>
4197The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4198the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4199<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4200features like scoped automatic variable sized arrays in C99.
4201</p>
4202
4203<h5>Semantics:</h5>
4204
4205<p>
4206This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4207href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4208<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4209<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4210state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4211practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4212that were allocated after the <tt>llvm.stacksave</tt> was executed.
4213</p>
4214
4215</div>
4216
4217<!-- _______________________________________________________________________ -->
4218<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4219 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4220</div>
4221
4222<div class="doc_text">
4223
4224<h5>Syntax:</h5>
4225<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4226 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4227</pre>
4228
4229<h5>Overview:</h5>
4230
4231<p>
4232The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4233the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4234href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4235useful for implementing language features like scoped automatic variable sized
4236arrays in C99.
4237</p>
4238
4239<h5>Semantics:</h5>
4240
4241<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4242See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4243</p>
4244
4245</div>
4246
4247
4248<!-- _______________________________________________________________________ -->
4249<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4250 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4251</div>
4252
4253<div class="doc_text">
4254
4255<h5>Syntax:</h5>
4256<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4257 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]4258</pre>
4259
4260<h5>Overview:</h5>
4261
4262
4263<p>
4264The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4265a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4266no
4267effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]4268characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4269</p>
4270
4271<h5>Arguments:</h5>
4272
4273<p>
4274<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4275determining if the fetch should be for a read (0) or write (1), and
4276<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]4277locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4278<tt>locality</tt> arguments must be constant integers.
4279</p>
4280
4281<h5>Semantics:</h5>
4282
4283<p>
4284This intrinsic does not modify the behavior of the program. In particular,
4285prefetches cannot trap and do not produce a value. On targets that support this
4286intrinsic, the prefetch can provide hints to the processor cache for better
4287performance.
4288</p>
4289
4290</div>
4291
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4292<!-- _______________________________________________________________________ -->
4293<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4294 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4295</div>
4296
4297<div class="doc_text">
4298
4299<h5>Syntax:</h5>
4300<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4301 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4302</pre>
4303
4304<h5>Overview:</h5>
4305
4306
4307<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4308The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
4309(PC) in a region of
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4310code to simulators and other tools. The method is target specific, but it is
4311expected that the marker will use exported symbols to transmit the PC of the marker.
Jeff Cohen25d4f7e2005-11-11 02:15:27 +0000[diff] [blame]4312The marker makes no guarantees that it will remain with any specific instruction
Chris Lattnerd07c3f42005-11-15 06:07:55 +0000[diff] [blame]4313after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]4314optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4315correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4316</p>
4317
4318<h5>Arguments:</h5>
4319
4320<p>
4321<tt>id</tt> is a numerical id identifying the marker.
4322</p>
4323
4324<h5>Semantics:</h5>
4325
4326<p>
4327This intrinsic does not modify the behavior of the program. Backends that do not
4328support this intrinisic may ignore it.
4329</p>
4330
4331</div>
4332
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4333<!-- _______________________________________________________________________ -->
4334<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4335 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4336</div>
4337
4338<div class="doc_text">
4339
4340<h5>Syntax:</h5>
4341<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4342 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4343</pre>
4344
4345<h5>Overview:</h5>
4346
4347
4348<p>
4349The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4350counter register (or similar low latency, high accuracy clocks) on those targets
4351that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4352As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4353should only be used for small timings.
4354</p>
4355
4356<h5>Semantics:</h5>
4357
4358<p>
4359When directly supported, reading the cycle counter should not modify any memory.
4360Implementations are allowed to either return a application specific value or a
4361system wide value. On backends without support, this is lowered to a constant 0.
4362</p>
4363
4364</div>
4365
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4366<!-- ======================================================================= -->
4367<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4368 <a name="int_libc">Standard C Library Intrinsics</a>
4369</div>
4370
4371<div class="doc_text">
4372<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4373LLVM provides intrinsics for a few important standard C library functions.
4374These intrinsics allow source-language front-ends to pass information about the
4375alignment of the pointer arguments to the code generator, providing opportunity
4376for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4377</p>
4378
4379</div>
4380
4381<!-- _______________________________________________________________________ -->
4382<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4383 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4384</div>
4385
4386<div class="doc_text">
4387
4388<h5>Syntax:</h5>
4389<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4390 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4391 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4392 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4393 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4394</pre>
4395
4396<h5>Overview:</h5>
4397
4398<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4399The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4400location to the destination location.
4401</p>
4402
4403<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4404Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
4405intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4406</p>
4407
4408<h5>Arguments:</h5>
4409
4410<p>
4411The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4412the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4413specifying the number of bytes to copy, and the fourth argument is the alignment
4414of the source and destination locations.
4415</p>
4416
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4417<p>
4418If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]4419the caller guarantees that both the source and destination pointers are aligned
4420to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4421</p>
4422
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4423<h5>Semantics:</h5>
4424
4425<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4426The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4427location to the destination location, which are not allowed to overlap. It
4428copies "len" bytes of memory over. If the argument is known to be aligned to
4429some boundary, this can be specified as the fourth argument, otherwise it should
4430be set to 0 or 1.
4431</p>
4432</div>
4433
4434
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4435<!-- _______________________________________________________________________ -->
4436<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4437 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4438</div>
4439
4440<div class="doc_text">
4441
4442<h5>Syntax:</h5>
4443<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4444 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4445 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4446 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4447 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4448</pre>
4449
4450<h5>Overview:</h5>
4451
4452<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4453The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
4454location to the destination location. It is similar to the
4455'<tt>llvm.memcmp</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4456</p>
4457
4458<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4459Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
4460intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4461</p>
4462
4463<h5>Arguments:</h5>
4464
4465<p>
4466The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4467the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4468specifying the number of bytes to copy, and the fourth argument is the alignment
4469of the source and destination locations.
4470</p>
4471
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4472<p>
4473If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]4474the caller guarantees that the source and destination pointers are aligned to
4475that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4476</p>
4477
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4478<h5>Semantics:</h5>
4479
4480<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4481The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4482location to the destination location, which may overlap. It
4483copies "len" bytes of memory over. If the argument is known to be aligned to
4484some boundary, this can be specified as the fourth argument, otherwise it should
4485be set to 0 or 1.
4486</p>
4487</div>
4488
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4489
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4490<!-- _______________________________________________________________________ -->
4491<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4492 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4493</div>
4494
4495<div class="doc_text">
4496
4497<h5>Syntax:</h5>
4498<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4499 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4500 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4501 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4502 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4503</pre>
4504
4505<h5>Overview:</h5>
4506
4507<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4508The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4509byte value.
4510</p>
4511
4512<p>
4513Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
4514does not return a value, and takes an extra alignment argument.
4515</p>
4516
4517<h5>Arguments:</h5>
4518
4519<p>
4520The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4521byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4522argument specifying the number of bytes to fill, and the fourth argument is the
4523known alignment of destination location.
4524</p>
4525
4526<p>
4527If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattnerf0afc2c2006-03-04 00:02:10 +0000[diff] [blame]4528the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4529</p>
4530
4531<h5>Semantics:</h5>
4532
4533<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4534The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
4535the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4536destination location. If the argument is known to be aligned to some boundary,
4537this can be specified as the fourth argument, otherwise it should be set to 0 or
45381.
4539</p>
4540</div>
4541
4542
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4543<!-- _______________________________________________________________________ -->
4544<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4545 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4546</div>
4547
4548<div class="doc_text">
4549
4550<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4551<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4552floating point or vector of floating point type. Not all targets support all
4553types however.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4554<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4555 declare float @llvm.sqrt.f32(float %Val)
4556 declare double @llvm.sqrt.f64(double %Val)
4557 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
4558 declare fp128 @llvm.sqrt.f128(fp128 %Val)
4559 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4560</pre>
4561
4562<h5>Overview:</h5>
4563
4564<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4565The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4566returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4567<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
4568negative numbers (which allows for better optimization).
4569</p>
4570
4571<h5>Arguments:</h5>
4572
4573<p>
4574The argument and return value are floating point numbers of the same type.
4575</p>
4576
4577<h5>Semantics:</h5>
4578
4579<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]4580This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4581floating point number.
4582</p>
4583</div>
4584
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4585<!-- _______________________________________________________________________ -->
4586<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4587 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4588</div>
4589
4590<div class="doc_text">
4591
4592<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4593<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4594floating point or vector of floating point type. Not all targets support all
4595types however.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4596<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4597 declare float @llvm.powi.f32(float %Val, i32 %power)
4598 declare double @llvm.powi.f64(double %Val, i32 %power)
4599 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
4600 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
4601 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4602</pre>
4603
4604<h5>Overview:</h5>
4605
4606<p>
4607The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
4608specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4609multiplications is not defined. When a vector of floating point type is
4610used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4611</p>
4612
4613<h5>Arguments:</h5>
4614
4615<p>
4616The second argument is an integer power, and the first is a value to raise to
4617that power.
4618</p>
4619
4620<h5>Semantics:</h5>
4621
4622<p>
4623This function returns the first value raised to the second power with an
4624unspecified sequence of rounding operations.</p>
4625</div>
4626
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4627<!-- _______________________________________________________________________ -->
4628<div class="doc_subsubsection">
4629 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
4630</div>
4631
4632<div class="doc_text">
4633
4634<h5>Syntax:</h5>
4635<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
4636floating point or vector of floating point type. Not all targets support all
4637types however.
4638<pre>
4639 declare float @llvm.sin.f32(float %Val)
4640 declare double @llvm.sin.f64(double %Val)
4641 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
4642 declare fp128 @llvm.sin.f128(fp128 %Val)
4643 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
4644</pre>
4645
4646<h5>Overview:</h5>
4647
4648<p>
4649The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
4650</p>
4651
4652<h5>Arguments:</h5>
4653
4654<p>
4655The argument and return value are floating point numbers of the same type.
4656</p>
4657
4658<h5>Semantics:</h5>
4659
4660<p>
4661This function returns the sine of the specified operand, returning the
4662same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4663conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4664</div>
4665
4666<!-- _______________________________________________________________________ -->
4667<div class="doc_subsubsection">
4668 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
4669</div>
4670
4671<div class="doc_text">
4672
4673<h5>Syntax:</h5>
4674<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
4675floating point or vector of floating point type. Not all targets support all
4676types however.
4677<pre>
4678 declare float @llvm.cos.f32(float %Val)
4679 declare double @llvm.cos.f64(double %Val)
4680 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
4681 declare fp128 @llvm.cos.f128(fp128 %Val)
4682 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
4683</pre>
4684
4685<h5>Overview:</h5>
4686
4687<p>
4688The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
4689</p>
4690
4691<h5>Arguments:</h5>
4692
4693<p>
4694The argument and return value are floating point numbers of the same type.
4695</p>
4696
4697<h5>Semantics:</h5>
4698
4699<p>
4700This function returns the cosine of the specified operand, returning the
4701same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4702conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4703</div>
4704
4705<!-- _______________________________________________________________________ -->
4706<div class="doc_subsubsection">
4707 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
4708</div>
4709
4710<div class="doc_text">
4711
4712<h5>Syntax:</h5>
4713<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
4714floating point or vector of floating point type. Not all targets support all
4715types however.
4716<pre>
4717 declare float @llvm.pow.f32(float %Val, float %Power)
4718 declare double @llvm.pow.f64(double %Val, double %Power)
4719 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
4720 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
4721 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
4722</pre>
4723
4724<h5>Overview:</h5>
4725
4726<p>
4727The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
4728specified (positive or negative) power.
4729</p>
4730
4731<h5>Arguments:</h5>
4732
4733<p>
4734The second argument is a floating point power, and the first is a value to
4735raise to that power.
4736</p>
4737
4738<h5>Semantics:</h5>
4739
4740<p>
4741This function returns the first value raised to the second power,
4742returning the
4743same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4744conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4745</div>
4746
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4747
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4748<!-- ======================================================================= -->
4749<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4750 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4751</div>
4752
4753<div class="doc_text">
4754<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4755LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4756These allow efficient code generation for some algorithms.
4757</p>
4758
4759</div>
4760
4761<!-- _______________________________________________________________________ -->
4762<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4763 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4764</div>
4765
4766<div class="doc_text">
4767
4768<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4769<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4770type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4771<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4772 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
4773 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
4774 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4775</pre>
4776
4777<h5>Overview:</h5>
4778
4779<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]4780The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4781values with an even number of bytes (positive multiple of 16 bits). These are
4782useful for performing operations on data that is not in the target's native
4783byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4784</p>
4785
4786<h5>Semantics:</h5>
4787
4788<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4789The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4790and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
4791intrinsic returns an i32 value that has the four bytes of the input i32
4792swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4793i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
4794<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4795additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4796</p>
4797
4798</div>
4799
4800<!-- _______________________________________________________________________ -->
4801<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4802 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4803</div>
4804
4805<div class="doc_text">
4806
4807<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4808<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
4809width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4810<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4811 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
4812 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4813 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4814 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
4815 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4816</pre>
4817
4818<h5>Overview:</h5>
4819
4820<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]4821The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
4822value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4823</p>
4824
4825<h5>Arguments:</h5>
4826
4827<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4828The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4829integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4830</p>
4831
4832<h5>Semantics:</h5>
4833
4834<p>
4835The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
4836</p>
4837</div>
4838
4839<!-- _______________________________________________________________________ -->
4840<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4841 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4842</div>
4843
4844<div class="doc_text">
4845
4846<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4847<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
4848integer bit width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4849<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4850 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
4851 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4852 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4853 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
4854 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4855</pre>
4856
4857<h5>Overview:</h5>
4858
4859<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4860The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
4861leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4862</p>
4863
4864<h5>Arguments:</h5>
4865
4866<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4867The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4868integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4869</p>
4870
4871<h5>Semantics:</h5>
4872
4873<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4874The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
4875in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4876of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4877</p>
4878</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4879
4880
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4881
4882<!-- _______________________________________________________________________ -->
4883<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4884 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4885</div>
4886
4887<div class="doc_text">
4888
4889<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4890<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
4891integer bit width. Not all targets support all bit widths however.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4892<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4893 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
4894 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4895 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4896 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
4897 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4898</pre>
4899
4900<h5>Overview:</h5>
4901
4902<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4903The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
4904trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4905</p>
4906
4907<h5>Arguments:</h5>
4908
4909<p>
4910The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4911integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4912</p>
4913
4914<h5>Semantics:</h5>
4915
4916<p>
4917The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
4918in a variable. If the src == 0 then the result is the size in bits of the type
4919of src. For example, <tt>llvm.cttz(2) = 1</tt>.
4920</p>
4921</div>
4922
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]4923<!-- _______________________________________________________________________ -->
4924<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4925 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4926</div>
4927
4928<div class="doc_text">
4929
4930<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4931<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4932on any integer bit width.
4933<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4934 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
4935 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4936</pre>
4937
4938<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4939<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4940range of bits from an integer value and returns them in the same bit width as
4941the original value.</p>
4942
4943<h5>Arguments:</h5>
4944<p>The first argument, <tt>%val</tt> and the result may be integer types of
4945any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4946arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4947
4948<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4949<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4950of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
4951<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
4952operates in forward mode.</p>
4953<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
4954right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4955only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
4956<ol>
4957 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
4958 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
4959 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
4960 to determine the number of bits to retain.</li>
4961 <li>A mask of the retained bits is created by shifting a -1 value.</li>
4962 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
4963</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]4964<p>In reverse mode, a similar computation is made except that the bits are
4965returned in the reverse order. So, for example, if <tt>X</tt> has the value
4966<tt>i16 0x0ACF (101011001111)</tt> and we apply
4967<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
4968<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4969</div>
4970
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]4971<div class="doc_subsubsection">
4972 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
4973</div>
4974
4975<div class="doc_text">
4976
4977<h5>Syntax:</h5>
4978<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
4979on any integer bit width.
4980<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4981 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
4982 declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]4983</pre>
4984
4985<h5>Overview:</h5>
4986<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
4987of bits in an integer value with another integer value. It returns the integer
4988with the replaced bits.</p>
4989
4990<h5>Arguments:</h5>
4991<p>The first argument, <tt>%val</tt> and the result may be integer types of
4992any bit width but they must have the same bit width. <tt>%val</tt> is the value
4993whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
4994integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
4995type since they specify only a bit index.</p>
4996
4997<h5>Semantics:</h5>
4998<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
4999of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5000<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5001operates in forward mode.</p>
5002<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5003truncating it down to the size of the replacement area or zero extending it
5004up to that size.</p>
5005<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5006are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5007in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
5008to the <tt>%hi</tt>th bit.
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5009<p>In reverse mode, a similar computation is made except that the bits are
5010reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
5011<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5012<h5>Examples:</h5>
5013<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5014 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5015 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5016 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5017 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5018 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5019</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5020</div>
5021
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5022<!-- ======================================================================= -->
5023<div class="doc_subsection">
5024 <a name="int_debugger">Debugger Intrinsics</a>
5025</div>
5026
5027<div class="doc_text">
5028<p>
5029The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5030are described in the <a
5031href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5032Debugging</a> document.
5033</p>
5034</div>
5035
5036
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5037<!-- ======================================================================= -->
5038<div class="doc_subsection">
5039 <a name="int_eh">Exception Handling Intrinsics</a>
5040</div>
5041
5042<div class="doc_text">
5043<p> The LLVM exception handling intrinsics (which all start with
5044<tt>llvm.eh.</tt> prefix), are described in the <a
5045href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5046Handling</a> document. </p>
5047</div>
5048
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5049<!-- ======================================================================= -->
5050<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5051 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5052</div>
5053
5054<div class="doc_text">
5055<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5056 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5057 the <tt>nest</tt> attribute, from a function. The result is a callable
5058 function pointer lacking the nest parameter - the caller does not need
5059 to provide a value for it. Instead, the value to use is stored in
5060 advance in a "trampoline", a block of memory usually allocated
5061 on the stack, which also contains code to splice the nest value into the
5062 argument list. This is used to implement the GCC nested function address
5063 extension.
5064</p>
5065<p>
5066 For example, if the function is
5067 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5068 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5069<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5070 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5071 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5072 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5073 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5074</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5075 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5076 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5077</div>
5078
5079<!-- _______________________________________________________________________ -->
5080<div class="doc_subsubsection">
5081 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5082</div>
5083<div class="doc_text">
5084<h5>Syntax:</h5>
5085<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5086declare 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]5087</pre>
5088<h5>Overview:</h5>
5089<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5090 This fills the memory pointed to by <tt>tramp</tt> with code
5091 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5092</p>
5093<h5>Arguments:</h5>
5094<p>
5095 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5096 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5097 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]5098 intrinsic. Note that the size and the alignment are target-specific - LLVM
5099 currently provides no portable way of determining them, so a front-end that
5100 generates this intrinsic needs to have some target-specific knowledge.
5101 The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5102</p>
5103<h5>Semantics:</h5>
5104<p>
5105 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5106 dependent code, turning it into a function. A pointer to this function is
5107 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5108 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5109 before being called. The new function's signature is the same as that of
5110 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5111 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5112 of pointer type. Calling the new function is equivalent to calling
5113 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5114 missing <tt>nest</tt> argument. If, after calling
5115 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5116 modified, then the effect of any later call to the returned function pointer is
5117 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5118</p>
5119</div>
5120
5121<!-- ======================================================================= -->
5122<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5123 <a name="int_general">General Intrinsics</a>
5124</div>
5125
5126<div class="doc_text">
5127<p> This class of intrinsics is designed to be generic and has
5128no specific purpose. </p>
5129</div>
5130
5131<!-- _______________________________________________________________________ -->
5132<div class="doc_subsubsection">
5133 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
5134</div>
5135
5136<div class="doc_text">
5137
5138<h5>Syntax:</h5>
5139<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]5140 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]5141</pre>
5142
5143<h5>Overview:</h5>
5144
5145<p>
5146The '<tt>llvm.var.annotation</tt>' intrinsic
5147</p>
5148
5149<h5>Arguments:</h5>
5150
5151<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]5152The first argument is a pointer to a value, the second is a pointer to a
5153global string, the third is a pointer to a global string which is the source
5154file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5155</p>
5156
5157<h5>Semantics:</h5>
5158
5159<p>
5160This intrinsic allows annotation of local variables with arbitrary strings.
5161This can be useful for special purpose optimizations that want to look for these
5162 annotations. These have no other defined use, they are ignored by code
5163 generation and optimization.
5164</div>
5165
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5166<!-- _______________________________________________________________________ -->
5167<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]5168 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5169</div>
5170
5171<div class="doc_text">
5172
5173<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5174<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
5175any integer bit width.
5176</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5177<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]5178 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5179 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5180 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5181 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5182 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]5183</pre>
5184
5185<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5186
5187<p>
5188The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5189</p>
5190
5191<h5>Arguments:</h5>
5192
5193<p>
5194The first argument is an integer value (result of some expression),
5195the second is a pointer to a global string, the third is a pointer to a global
5196string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5197It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5198</p>
5199
5200<h5>Semantics:</h5>
5201
5202<p>
5203This intrinsic allows annotations to be put on arbitrary expressions
5204with arbitrary strings. This can be useful for special purpose optimizations
5205that want to look for these annotations. These have no other defined use, they
5206are ignored by code generation and optimization.
5207</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5208
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5209<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5210<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]5211<address>
5212 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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5216
5217 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]5218 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]5219 Last modified: $Date$
5220</address>
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