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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 23ff1f910f5662be275b2c6bf40055d88579675a / . / 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 Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]43 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]44 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]45 <li><a href="#t_function">Function Type</a></li>
46 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]47 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]48 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]49 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]50 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]51 </ol>
52 </li>
53 </ol>
54 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]55 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]56 <ol>
57 <li><a href="#simpleconstants">Simple Constants</a>
58 <li><a href="#aggregateconstants">Aggregate Constants</a>
59 <li><a href="#globalconstants">Global Variable and Function Addresses</a>
60 <li><a href="#undefvalues">Undefined Values</a>
61 <li><a href="#constantexprs">Constant Expressions</a>
62 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]63 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]64 <li><a href="#othervalues">Other Values</a>
65 <ol>
66 <li><a href="#inlineasm">Inline Assembler Expressions</a>
67 </ol>
68 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]69 <li><a href="#instref">Instruction Reference</a>
70 <ol>
71 <li><a href="#terminators">Terminator Instructions</a>
72 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]73 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
74 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]75 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
76 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]77 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]78 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]79 </ol>
80 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]81 <li><a href="#binaryops">Binary Operations</a>
82 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]83 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
84 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
85 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]86 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
87 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
88 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]89 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
90 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
91 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]92 </ol>
93 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]94 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
95 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]96 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
97 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
98 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]99 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]100 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]101 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]102 </ol>
103 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]104 <li><a href="#vectorops">Vector Operations</a>
105 <ol>
106 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
107 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
108 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]109 </ol>
110 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]111 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]112 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]113 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
114 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
115 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]116 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
117 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
118 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]119 </ol>
120 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]121 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]122 <ol>
123 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
124 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
125 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
126 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
127 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]128 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
129 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
130 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
131 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]132 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
133 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]134 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]135 </ol>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]136 <li><a href="#otherops">Other Operations</a>
137 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]138 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
139 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]140 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]141 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]142 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]143 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]144 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]145 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]146 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]147 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]148 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]149 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]150 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
151 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]152 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
153 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
154 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]155 </ol>
156 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]157 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
158 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]159 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
160 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
161 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]162 </ol>
163 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]164 <li><a href="#int_codegen">Code Generator Intrinsics</a>
165 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]166 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
167 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
168 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
169 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
170 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
171 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
172 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]173 </ol>
174 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]175 <li><a href="#int_libc">Standard C Library Intrinsics</a>
176 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]177 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
178 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
179 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
180 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
181 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]182 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
183 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
184 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]185 </ol>
186 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]187 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]188 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]189 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]190 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
191 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
192 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]193 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
194 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]195 </ol>
196 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]197 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]198 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]199 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]200 <ol>
201 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]202 </ol>
203 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]204 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]205 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]206 <li><a href="#int_var_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]207 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]208 </ol>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]209 <ol>
210 <li><a href="#int_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]211 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]212 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]213 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]214 </ol>
215 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]216</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]217
218<div class="doc_author">
219 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
220 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]221</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]222
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]223<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]224<div class="doc_section"> <a name="abstract">Abstract </a></div>
225<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]226
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]227<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]228<p>This document is a reference manual for the LLVM assembly language.
229LLVM is an SSA based representation that provides type safety,
230low-level operations, flexibility, and the capability of representing
231'all' high-level languages cleanly. It is the common code
232representation used throughout all phases of the LLVM compilation
233strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]234</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]235
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]236<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]237<div class="doc_section"> <a name="introduction">Introduction</a> </div>
238<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]239
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]240<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]241
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]242<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]243different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]244representation (suitable for fast loading by a Just-In-Time compiler),
245and as a human readable assembly language representation. This allows
246LLVM to provide a powerful intermediate representation for efficient
247compiler transformations and analysis, while providing a natural means
248to debug and visualize the transformations. The three different forms
249of LLVM are all equivalent. This document describes the human readable
250representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]251
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]252<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]253while being expressive, typed, and extensible at the same time. It
254aims to be a "universal IR" of sorts, by being at a low enough level
255that high-level ideas may be cleanly mapped to it (similar to how
256microprocessors are "universal IR's", allowing many source languages to
257be mapped to them). By providing type information, LLVM can be used as
258the target of optimizations: for example, through pointer analysis, it
259can be proven that a C automatic variable is never accessed outside of
260the current function... allowing it to be promoted to a simple SSA
261value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]262
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]263</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]264
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]265<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]266<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]267
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]268<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]269
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]270<p>It is important to note that this document describes 'well formed'
271LLVM assembly language. There is a difference between what the parser
272accepts and what is considered 'well formed'. For example, the
273following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]274
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]275<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]276<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]277%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]278</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]279</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]280
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]281<p>...because the definition of <tt>%x</tt> does not dominate all of
282its uses. The LLVM infrastructure provides a verification pass that may
283be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]284automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]285the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]286by the verifier pass indicate bugs in transformation passes or input to
287the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]288</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]289
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]290<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]291
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]292<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]293<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]294<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]295
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]296<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]297
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]298 <p>LLVM identifiers come in two basic types: global and local. Global
299 identifiers (functions, global variables) begin with the @ character. Local
300 identifiers (register names, types) begin with the % character. Additionally,
301 there are three different formats for identifiers, for different purposes:
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]302
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]303<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]304 <li>Named values are represented as a string of characters with their prefix.
305 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
306 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]307 Identifiers which require other characters in their names can be surrounded
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]308 with quotes. In this way, anything except a <tt>&quot;</tt> character can
309 be used in a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]310
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]311 <li>Unnamed values are represented as an unsigned numeric value with their
312 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]313
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]314 <li>Constants, which are described in a <a href="#constants">section about
315 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]316</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]317
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]318<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]319don't need to worry about name clashes with reserved words, and the set of
320reserved words may be expanded in the future without penalty. Additionally,
321unnamed identifiers allow a compiler to quickly come up with a temporary
322variable without having to avoid symbol table conflicts.</p>
323
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]324<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]325languages. There are keywords for different opcodes
326('<tt><a href="#i_add">add</a></tt>',
327 '<tt><a href="#i_bitcast">bitcast</a></tt>',
328 '<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]329href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]330and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]331none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]332
333<p>Here is an example of LLVM code to multiply the integer variable
334'<tt>%X</tt>' by 8:</p>
335
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]336<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]337
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]338<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]339<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]340%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]341</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]342</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]343
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]344<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]345
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]346<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]347<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]348%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]349</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]350</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]351
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]352<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]353
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]354<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]355<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]356<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
357<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
358%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]359</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]360</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]361
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]362<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
363important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]364
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]365<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]366
367 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
368 line.</li>
369
370 <li>Unnamed temporaries are created when the result of a computation is not
371 assigned to a named value.</li>
372
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]373 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]374
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]375</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]376
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]377<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]378demonstrating instructions, we will follow an instruction with a comment that
379defines the type and name of value produced. Comments are shown in italic
380text.</p>
381
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]382</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]383
384<!-- *********************************************************************** -->
385<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
386<!-- *********************************************************************** -->
387
388<!-- ======================================================================= -->
389<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
390</div>
391
392<div class="doc_text">
393
394<p>LLVM programs are composed of "Module"s, each of which is a
395translation unit of the input programs. Each module consists of
396functions, global variables, and symbol table entries. Modules may be
397combined together with the LLVM linker, which merges function (and
398global variable) definitions, resolves forward declarations, and merges
399symbol table entries. Here is an example of the "hello world" module:</p>
400
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]401<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]402<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]403<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
404 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]405
406<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]407<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]408
409<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]410define i32 @main() { <i>; i32()* </i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]411 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]412 %cast210 = <a
Chris Lattner6c0955b2007-06-12 17:01:15 +0000[diff] [blame]413 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]414
415 <i>; Call puts function to write out the string to stdout...</i>
416 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]417 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]418 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]419 href="#i_ret">ret</a> i32 0<br>}<br>
420</pre>
421</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]422
423<p>This example is made up of a <a href="#globalvars">global variable</a>
424named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
425function, and a <a href="#functionstructure">function definition</a>
426for "<tt>main</tt>".</p>
427
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]428<p>In general, a module is made up of a list of global values,
429where both functions and global variables are global values. Global values are
430represented by a pointer to a memory location (in this case, a pointer to an
431array of char, and a pointer to a function), and have one of the following <a
432href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]433
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]434</div>
435
436<!-- ======================================================================= -->
437<div class="doc_subsection">
438 <a name="linkage">Linkage Types</a>
439</div>
440
441<div class="doc_text">
442
443<p>
444All Global Variables and Functions have one of the following types of linkage:
445</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]446
447<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]448
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]449 <dt><tt><b><a name="linkage_internal">internal</a></b></tt> </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]450
451 <dd>Global values with internal linkage are only directly accessible by
452 objects in the current module. In particular, linking code into a module with
453 an internal global value may cause the internal to be renamed as necessary to
454 avoid collisions. Because the symbol is internal to the module, all
455 references can be updated. This corresponds to the notion of the
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]456 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]457 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]458
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]459 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]460
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]461 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
462 the same name when linkage occurs. This is typically used to implement
463 inline functions, templates, or other code which must be generated in each
464 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
465 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]466 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]467
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]468 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]469
470 <dd>"<tt>weak</tt>" linkage is exactly the same as <tt>linkonce</tt> linkage,
471 except that unreferenced <tt>weak</tt> globals may not be discarded. This is
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]472 used for globals that may be emitted in multiple translation units, but that
473 are not guaranteed to be emitted into every translation unit that uses them.
474 One example of this are common globals in C, such as "<tt>int X;</tt>" at
475 global scope.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]476 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]477
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]478 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]479
480 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
481 pointer to array type. When two global variables with appending linkage are
482 linked together, the two global arrays are appended together. This is the
483 LLVM, typesafe, equivalent of having the system linker append together
484 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]485 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]486
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]487 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
488 <dd>The semantics of this linkage follow the ELF model: the symbol is weak
489 until linked, if not linked, the symbol becomes null instead of being an
490 undefined reference.
491 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]492
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]493 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]494
495 <dd>If none of the above identifiers are used, the global is externally
496 visible, meaning that it participates in linkage and can be used to resolve
497 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]498 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]499</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]500
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]501 <p>
502 The next two types of linkage are targeted for Microsoft Windows platform
503 only. They are designed to support importing (exporting) symbols from (to)
504 DLLs.
505 </p>
506
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]507 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]508 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
509
510 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
511 or variable via a global pointer to a pointer that is set up by the DLL
512 exporting the symbol. On Microsoft Windows targets, the pointer name is
513 formed by combining <code>_imp__</code> and the function or variable name.
514 </dd>
515
516 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
517
518 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
519 pointer to a pointer in a DLL, so that it can be referenced with the
520 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
521 name is formed by combining <code>_imp__</code> and the function or variable
522 name.
523 </dd>
524
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]525</dl>
526
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]527<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]528variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
529variable and was linked with this one, one of the two would be renamed,
530preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
531external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]532outside of the current module.</p>
533<p>It is illegal for a function <i>declaration</i>
534to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]535or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]536<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
537linkages.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]538</div>
539
540<!-- ======================================================================= -->
541<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]542 <a name="callingconv">Calling Conventions</a>
543</div>
544
545<div class="doc_text">
546
547<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
548and <a href="#i_invoke">invokes</a> can all have an optional calling convention
549specified for the call. The calling convention of any pair of dynamic
550caller/callee must match, or the behavior of the program is undefined. The
551following calling conventions are supported by LLVM, and more may be added in
552the future:</p>
553
554<dl>
555 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
556
557 <dd>This calling convention (the default if no other calling convention is
558 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]559 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]560 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]561 </dd>
562
563 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
564
565 <dd>This calling convention attempts to make calls as fast as possible
566 (e.g. by passing things in registers). This calling convention allows the
567 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner8cdc5bc2005-05-06 23:08:23 +0000[diff] [blame]568 without having to conform to an externally specified ABI. Implementations of
569 this convention should allow arbitrary tail call optimization to be supported.
570 This calling convention does not support varargs and requires the prototype of
571 all callees to exactly match the prototype of the function definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]572 </dd>
573
574 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
575
576 <dd>This calling convention attempts to make code in the caller as efficient
577 as possible under the assumption that the call is not commonly executed. As
578 such, these calls often preserve all registers so that the call does not break
579 any live ranges in the caller side. This calling convention does not support
580 varargs and requires the prototype of all callees to exactly match the
581 prototype of the function definition.
582 </dd>
583
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]584 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]585
586 <dd>Any calling convention may be specified by number, allowing
587 target-specific calling conventions to be used. Target specific calling
588 conventions start at 64.
589 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]590</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]591
592<p>More calling conventions can be added/defined on an as-needed basis, to
593support pascal conventions or any other well-known target-independent
594convention.</p>
595
596</div>
597
598<!-- ======================================================================= -->
599<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]600 <a name="visibility">Visibility Styles</a>
601</div>
602
603<div class="doc_text">
604
605<p>
606All Global Variables and Functions have one of the following visibility styles:
607</p>
608
609<dl>
610 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
611
612 <dd>On ELF, default visibility means that the declaration is visible to other
613 modules and, in shared libraries, means that the declared entity may be
614 overridden. On Darwin, default visibility means that the declaration is
615 visible to other modules. Default visibility corresponds to "external
616 linkage" in the language.
617 </dd>
618
619 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
620
621 <dd>Two declarations of an object with hidden visibility refer to the same
622 object if they are in the same shared object. Usually, hidden visibility
623 indicates that the symbol will not be placed into the dynamic symbol table,
624 so no other module (executable or shared library) can reference it
625 directly.
626 </dd>
627
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]628 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
629
630 <dd>On ELF, protected visibility indicates that the symbol will be placed in
631 the dynamic symbol table, but that references within the defining module will
632 bind to the local symbol. That is, the symbol cannot be overridden by another
633 module.
634 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]635</dl>
636
637</div>
638
639<!-- ======================================================================= -->
640<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]641 <a name="globalvars">Global Variables</a>
642</div>
643
644<div class="doc_text">
645
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]646<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]647instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]648an explicit section to be placed in, and may have an optional explicit alignment
649specified. A variable may be defined as "thread_local", which means that it
650will not be shared by threads (each thread will have a separated copy of the
651variable). A variable may be defined as a global "constant," which indicates
652that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]653optimization, allowing the global data to be placed in the read-only section of
654an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]655cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]656
657<p>
658LLVM explicitly allows <em>declarations</em> of global variables to be marked
659constant, even if the final definition of the global is not. This capability
660can be used to enable slightly better optimization of the program, but requires
661the language definition to guarantee that optimizations based on the
662'constantness' are valid for the translation units that do not include the
663definition.
664</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]665
666<p>As SSA values, global variables define pointer values that are in
667scope (i.e. they dominate) all basic blocks in the program. Global
668variables always define a pointer to their "content" type because they
669describe a region of memory, and all memory objects in LLVM are
670accessed through pointers.</p>
671
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]672<p>A global variable may be declared to reside in a target-specifc numbered
673address space. For targets that support them, address spaces may affect how
674optimizations are performed and/or what target instructions are used to access
Christopher Lambd49e18d2007-12-12 08:44:39 +0000[diff] [blame]675the variable. The default address space is zero. The address space qualifier
676must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]677
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]678<p>LLVM allows an explicit section to be specified for globals. If the target
679supports it, it will emit globals to the section specified.</p>
680
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]681<p>An explicit alignment may be specified for a global. If not present, or if
682the alignment is set to zero, the alignment of the global is set by the target
683to whatever it feels convenient. If an explicit alignment is specified, the
684global is forced to have at least that much alignment. All alignments must be
685a power of 2.</p>
686
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]687<p>For example, the following defines a global in a numbered address space with
688an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]689
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]690<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]691<pre>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]692@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]693</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]694</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]695
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]696</div>
697
698
699<!-- ======================================================================= -->
700<div class="doc_subsection">
701 <a name="functionstructure">Functions</a>
702</div>
703
704<div class="doc_text">
705
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]706<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
707an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]708<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]709<a href="#callingconv">calling convention</a>, a return type, an optional
710<a href="#paramattrs">parameter attribute</a> for the return type, a function
711name, a (possibly empty) argument list (each with optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]712<a href="#paramattrs">parameter attributes</a>), an optional section, an
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]713optional alignment, an optional <a href="#gc">garbage collector name</a>, an
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]714opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]715
716LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
717optional <a href="#linkage">linkage type</a>, an optional
718<a href="#visibility">visibility style</a>, an optional
719<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]720<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]721name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksene754abe2007-12-10 03:30:21 +0000[diff] [blame]722<a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]723
724<p>A function definition contains a list of basic blocks, forming the CFG for
725the function. Each basic block may optionally start with a label (giving the
726basic block a symbol table entry), contains a list of instructions, and ends
727with a <a href="#terminators">terminator</a> instruction (such as a branch or
728function return).</p>
729
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]730<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]731executed on entrance to the function, and it is not allowed to have predecessor
732basic blocks (i.e. there can not be any branches to the entry block of a
733function). Because the block can have no predecessors, it also cannot have any
734<a href="#i_phi">PHI nodes</a>.</p>
735
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]736<p>LLVM allows an explicit section to be specified for functions. If the target
737supports it, it will emit functions to the section specified.</p>
738
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]739<p>An explicit alignment may be specified for a function. If not present, or if
740the alignment is set to zero, the alignment of the function is set by the target
741to whatever it feels convenient. If an explicit alignment is specified, the
742function is forced to have at least that much alignment. All alignments must be
743a power of 2.</p>
744
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]745</div>
746
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]747
748<!-- ======================================================================= -->
749<div class="doc_subsection">
750 <a name="aliasstructure">Aliases</a>
751</div>
752<div class="doc_text">
753 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikova80e1182007-04-28 13:45:00 +0000[diff] [blame]754 function or global variable or bitcast of global value). Aliases may have an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]755 optional <a href="#linkage">linkage type</a>, and an
756 optional <a href="#visibility">visibility style</a>.</p>
757
758 <h5>Syntax:</h5>
759
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]760<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]761<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]762@&lt;Name&gt; = [Linkage] [Visibility] alias &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]763</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]764</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]765
766</div>
767
768
769
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]770<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]771<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
772<div class="doc_text">
773 <p>The return type and each parameter of a function type may have a set of
774 <i>parameter attributes</i> associated with them. Parameter attributes are
775 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]776 a function. Parameter attributes are considered to be part of the function,
777 not of the function type, so functions with different parameter attributes
778 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]779
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]780 <p>Parameter attributes are simple keywords that follow the type specified. If
781 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]782 example:</p>
783
784<div class="doc_code">
785<pre>
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]786declare i32 @printf(i8* noalias , ...) nounwind
787declare i32 @atoi(i8*) nounwind readonly
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]788</pre>
789</div>
790
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame]791 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
792 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]793
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]794 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]795 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]796 <dt><tt>zeroext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]797 <dd>This indicates that the parameter should be zero extended just before
798 a call to this function.</dd>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]799 <dt><tt>signext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]800 <dd>This indicates that the parameter should be sign extended just before
801 a call to this function.</dd>
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]802 <dt><tt>inreg</tt></dt>
803 <dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000[diff] [blame]804 possible) during assembling function call. Support for this attribute is
805 target-specific</dd>
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]806 <dt><tt>sret</tt></dt>
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000[diff] [blame]807 <dd>This indicates that the parameter specifies the address of a structure
Reid Spencer67606122007-03-22 02:02:11 +0000[diff] [blame]808 that is the return value of the function in the source program.</dd>
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]809 <dt><tt>noalias</tt></dt>
810 <dd>This indicates that the parameter not alias any other object or any
811 other "noalias" objects during the function call.
Reid Spencer2dc52012007-03-22 02:18:56 +0000[diff] [blame]812 <dt><tt>noreturn</tt></dt>
813 <dd>This function attribute indicates that the function never returns. This
814 indicates to LLVM that every call to this function should be treated as if
815 an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Reid Spencer67606122007-03-22 02:02:11 +0000[diff] [blame]816 <dt><tt>nounwind</tt></dt>
817 <dd>This function attribute indicates that the function type does not use
818 the unwind instruction and does not allow stack unwinding to propagate
819 through it.</dd>
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]820 <dt><tt>nest</tt></dt>
821 <dd>This indicates that the parameter can be excised using the
822 <a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sandsed4a2f12007-11-22 20:23:04 +0000[diff] [blame]823 <dt><tt>readonly</tt></dt>
Duncan Sandsf04d5842007-11-14 21:14:02 +0000[diff] [blame]824 <dd>This function attribute indicates that the function has no side-effects
Duncan Sandsed4a2f12007-11-22 20:23:04 +0000[diff] [blame]825 except for producing a return value or throwing an exception. The value
826 returned must only depend on the function arguments and/or global variables.
827 It may use values obtained by dereferencing pointers.</dd>
828 <dt><tt>readnone</tt></dt>
829 <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]830 function, but in addition it is not allowed to dereference any pointer arguments
831 or global variables.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]832 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]833
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]834</div>
835
836<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]837<div class="doc_subsection">
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]838 <a name="gc">Garbage Collector Names</a>
839</div>
840
841<div class="doc_text">
842<p>Each function may specify a garbage collector name, which is simply a
843string.</p>
844
845<div class="doc_code"><pre
846>define void @f() gc "name" { ...</pre></div>
847
848<p>The compiler declares the supported values of <i>name</i>. Specifying a
849collector which will cause the compiler to alter its output in order to support
850the named garbage collection algorithm.</p>
851</div>
852
853<!-- ======================================================================= -->
854<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]855 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]856</div>
857
858<div class="doc_text">
859<p>
860Modules may contain "module-level inline asm" blocks, which corresponds to the
861GCC "file scope inline asm" blocks. These blocks are internally concatenated by
862LLVM and treated as a single unit, but may be separated in the .ll file if
863desired. The syntax is very simple:
864</p>
865
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]866<div class="doc_code">
867<pre>
868module asm "inline asm code goes here"
869module asm "more can go here"
870</pre>
871</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]872
873<p>The strings can contain any character by escaping non-printable characters.
874 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
875 for the number.
876</p>
877
878<p>
879 The inline asm code is simply printed to the machine code .s file when
880 assembly code is generated.
881</p>
882</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]883
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]884<!-- ======================================================================= -->
885<div class="doc_subsection">
886 <a name="datalayout">Data Layout</a>
887</div>
888
889<div class="doc_text">
890<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]891data is to be laid out in memory. The syntax for the data layout is simply:</p>
892<pre> target datalayout = "<i>layout specification</i>"</pre>
893<p>The <i>layout specification</i> consists of a list of specifications
894separated by the minus sign character ('-'). Each specification starts with a
895letter and may include other information after the letter to define some
896aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]897<dl>
898 <dt><tt>E</tt></dt>
899 <dd>Specifies that the target lays out data in big-endian form. That is, the
900 bits with the most significance have the lowest address location.</dd>
901 <dt><tt>e</tt></dt>
902 <dd>Specifies that hte target lays out data in little-endian form. That is,
903 the bits with the least significance have the lowest address location.</dd>
904 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
905 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
906 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
907 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
908 too.</dd>
909 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
910 <dd>This specifies the alignment for an integer type of a given bit
911 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
912 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
913 <dd>This specifies the alignment for a vector type of a given bit
914 <i>size</i>.</dd>
915 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
916 <dd>This specifies the alignment for a floating point type of a given bit
917 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
918 (double).</dd>
919 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
920 <dd>This specifies the alignment for an aggregate type of a given bit
921 <i>size</i>.</dd>
922</dl>
923<p>When constructing the data layout for a given target, LLVM starts with a
924default set of specifications which are then (possibly) overriden by the
925specifications in the <tt>datalayout</tt> keyword. The default specifications
926are given in this list:</p>
927<ul>
928 <li><tt>E</tt> - big endian</li>
929 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
930 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
931 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
932 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
933 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
934 <li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
935 alignment of 64-bits</li>
936 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
937 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
938 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
939 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
940 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
941</ul>
942<p>When llvm is determining the alignment for a given type, it uses the
943following rules:
944<ol>
945 <li>If the type sought is an exact match for one of the specifications, that
946 specification is used.</li>
947 <li>If no match is found, and the type sought is an integer type, then the
948 smallest integer type that is larger than the bitwidth of the sought type is
949 used. If none of the specifications are larger than the bitwidth then the the
950 largest integer type is used. For example, given the default specifications
951 above, the i7 type will use the alignment of i8 (next largest) while both
952 i65 and i256 will use the alignment of i64 (largest specified).</li>
953 <li>If no match is found, and the type sought is a vector type, then the
954 largest vector type that is smaller than the sought vector type will be used
955 as a fall back. This happens because <128 x double> can be implemented in
956 terms of 64 <2 x double>, for example.</li>
957</ol>
958</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]959
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]960<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]961<div class="doc_section"> <a name="typesystem">Type System</a> </div>
962<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]963
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]964<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]965
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]966<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]967intermediate representation. Being typed enables a number of
968optimizations to be performed on the IR directly, without having to do
969extra analyses on the side before the transformation. A strong type
970system makes it easier to read the generated code and enables novel
971analyses and transformations that are not feasible to perform on normal
972three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]973
974</div>
975
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]976<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]977<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]978<div class="doc_text">
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]979<p>The primitive types are the fundamental building blocks of the LLVM
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]980system. The current set of primitive types is as follows:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]981
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]982<table class="layout">
983 <tr class="layout">
984 <td class="left">
985 <table>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]986 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]987 <tr><th>Type</th><th>Description</th></tr>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]988 <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]989 <tr><td><tt>label</tt></td><td>Branch destination</td></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]990 </tbody>
991 </table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]992 </td>
993 <td class="right">
994 <table>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]995 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]996 <tr><th>Type</th><th>Description</th></tr>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]997 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]998 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]999 </tbody>
1000 </table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1001 </td>
1002 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1003</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1004</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1005
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1006<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1007<div class="doc_subsubsection"> <a name="t_classifications">Type
1008Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1009<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1010<p>These different primitive types fall into a few useful
1011classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1012
1013<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1014 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1015 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1016 <tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1017 <td><a name="t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1018 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1019 </tr>
1020 <tr>
1021 <td><a name="t_floating">floating point</a></td>
1022 <td><tt>float, double</tt></td>
1023 </tr>
1024 <tr>
1025 <td><a name="t_firstclass">first class</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1026 <td><tt>i1, ..., float, double, <br/>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1027 <a href="#t_pointer">pointer</a>,<a href="#t_vector">vector</a></tt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1028 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1029 </tr>
1030 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1031</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1032
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1033<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1034most important. Values of these types are the only ones which can be
1035produced by instructions, passed as arguments, or used as operands to
1036instructions. This means that all structures and arrays must be
1037manipulated either by pointer or by component.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1038</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1039
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1040<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1041<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1042
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1043<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1044
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1045<p>The real power in LLVM comes from the derived types in the system.
1046This is what allows a programmer to represent arrays, functions,
1047pointers, and other useful types. Note that these derived types may be
1048recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1049
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1050</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1051
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1052<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1053<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1054
1055<div class="doc_text">
1056
1057<h5>Overview:</h5>
1058<p>The integer type is a very simple derived type that simply specifies an
1059arbitrary bit width for the integer type desired. Any bit width from 1 bit to
10602^23-1 (about 8 million) can be specified.</p>
1061
1062<h5>Syntax:</h5>
1063
1064<pre>
1065 iN
1066</pre>
1067
1068<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1069value.</p>
1070
1071<h5>Examples:</h5>
1072<table class="layout">
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1073 <tbody>
1074 <tr>
1075 <td><tt>i1</tt></td>
1076 <td>a single-bit integer.</td>
1077 </tr><tr>
1078 <td><tt>i32</tt></td>
1079 <td>a 32-bit integer.</td>
1080 </tr><tr>
1081 <td><tt>i1942652</tt></td>
1082 <td>a really big integer of over 1 million bits.</td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1083 </tr>
Chris Lattnerb9488a62007-12-18 06:18:21 +0000[diff] [blame]1084 </tbody>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1085</table>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1086</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1087
1088<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1089<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1090
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1091<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1092
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1093<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1094
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1095<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1096sequentially in memory. The array type requires a size (number of
1097elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1098
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1099<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1100
1101<pre>
1102 [&lt;# elements&gt; x &lt;elementtype&gt;]
1103</pre>
1104
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1105<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1106be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1107
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1108<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1109<table class="layout">
1110 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame^]1111 <td class="left"><tt>[40 x i32]</tt></td>
1112 <td class="left">Array of 40 32-bit integer values.</td>
1113 </tr>
1114 <tr class="layout">
1115 <td class="left"><tt>[41 x i32]</tt></td>
1116 <td class="left">Array of 41 32-bit integer values.</td>
1117 </tr>
1118 <tr class="layout">
1119 <td class="left"><tt>[4 x i8]</tt></td>
1120 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1121 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1122</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1123<p>Here are some examples of multidimensional arrays:</p>
1124<table class="layout">
1125 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame^]1126 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1127 <td class="left">3x4 array of 32-bit integer values.</td>
1128 </tr>
1129 <tr class="layout">
1130 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1131 <td class="left">12x10 array of single precision floating point values.</td>
1132 </tr>
1133 <tr class="layout">
1134 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1135 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1136 </tr>
1137</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1138
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1139<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1140length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1141LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1142As a special case, however, zero length arrays are recognized to be variable
1143length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1144type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1145
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1146</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1147
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1148<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1149<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1150<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1151<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1152<p>The function type can be thought of as a function signature. It
1153consists of a return type and a list of formal parameter types.
John Criswell009900b2003-11-25 21:45:46 +0000[diff] [blame]1154Function types are usually used to build virtual function tables
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1155(which are structures of pointers to functions), for indirect function
1156calls, and when defining a function.</p>
John Criswell009900b2003-11-25 21:45:46 +0000[diff] [blame]1157<p>
1158The return type of a function type cannot be an aggregate type.
1159</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1160<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1161<pre> &lt;returntype&gt; (&lt;parameter list&gt;)<br></pre>
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1162<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]1163specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1164which indicates that the function takes a variable number of arguments.
1165Variable argument functions can access their arguments with the <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1166 href="#int_varargs">variable argument handling intrinsic</a> functions.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1167<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1168<table class="layout">
1169 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1170 <td class="left"><tt>i32 (i32)</tt></td>
1171 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1172 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1173 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1174 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1175 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1176 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1177 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1178 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1179 <tt>float</tt>.
1180 </td>
1181 </tr><tr class="layout">
1182 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1183 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1184 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1185 which returns an integer. This is the signature for <tt>printf</tt> in
1186 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1187 </td>
1188 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1189</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1190
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1191</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1192<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1193<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1194<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1195<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1196<p>The structure type is used to represent a collection of data members
1197together in memory. The packing of the field types is defined to match
1198the ABI of the underlying processor. The elements of a structure may
1199be any type that has a size.</p>
1200<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1201and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1202field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1203instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1204<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1205<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1206<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1207<table class="layout">
1208 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1209 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1210 <td class="left">A triple of three <tt>i32</tt> values</td>
1211 </tr><tr class="layout">
1212 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1213 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1214 second element is a <a href="#t_pointer">pointer</a> to a
1215 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1216 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1217 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1218</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1219</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1220
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1221<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1222<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1223</div>
1224<div class="doc_text">
1225<h5>Overview:</h5>
1226<p>The packed structure type is used to represent a collection of data members
1227together in memory. There is no padding between fields. Further, the alignment
1228of a packed structure is 1 byte. The elements of a packed structure may
1229be any type that has a size.</p>
1230<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1231and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1232field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1233instruction.</p>
1234<h5>Syntax:</h5>
1235<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1236<h5>Examples:</h5>
1237<table class="layout">
1238 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1239 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1240 <td class="left">A triple of three <tt>i32</tt> values</td>
1241 </tr><tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame^]1242 <td class="left"><tt>&lt; { float, i32 (i32)* } &gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1243 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1244 second element is a <a href="#t_pointer">pointer</a> to a
1245 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1246 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1247 </tr>
1248</table>
1249</div>
1250
1251<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1252<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1253<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1254<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1255<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1256reference to another object, which must live in memory. Pointer types may have
1257an optional address space attribute defining the target-specific numbered
1258address space where the pointed-to object resides. The default address space is
1259zero.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1260<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1261<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1262<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1263<table class="layout">
1264 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame^]1265 <td class="left"><tt>[4x i32]*</tt></td>
1266 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1267 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1268 </tr>
1269 <tr class="layout">
1270 <td class="left"><tt>i32 (i32 *) *</tt></td>
1271 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1272 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame^]1273 <tt>i32</tt>.</td>
1274 </tr>
1275 <tr class="layout">
1276 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1277 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1278 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1279 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1280</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1281</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1282
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1283<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1284<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1285<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1286
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1287<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1288
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1289<p>A vector type is a simple derived type that represents a vector
1290of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1291are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1292A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1293elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1294of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1295considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1296
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1297<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1298
1299<pre>
1300 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1301</pre>
1302
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1303<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1304be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1305
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1306<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1307
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1308<table class="layout">
1309 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame^]1310 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1311 <td class="left">Vector of 4 32-bit integer values.</td>
1312 </tr>
1313 <tr class="layout">
1314 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1315 <td class="left">Vector of 8 32-bit floating-point values.</td>
1316 </tr>
1317 <tr class="layout">
1318 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1319 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1320 </tr>
1321</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1322</div>
1323
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1324<!-- _______________________________________________________________________ -->
1325<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1326<div class="doc_text">
1327
1328<h5>Overview:</h5>
1329
1330<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1331corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1332In LLVM, opaque types can eventually be resolved to any type (not just a
1333structure type).</p>
1334
1335<h5>Syntax:</h5>
1336
1337<pre>
1338 opaque
1339</pre>
1340
1341<h5>Examples:</h5>
1342
1343<table class="layout">
1344 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame^]1345 <td class="left"><tt>opaque</tt></td>
1346 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1347 </tr>
1348</table>
1349</div>
1350
1351
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1352<!-- *********************************************************************** -->
1353<div class="doc_section"> <a name="constants">Constants</a> </div>
1354<!-- *********************************************************************** -->
1355
1356<div class="doc_text">
1357
1358<p>LLVM has several different basic types of constants. This section describes
1359them all and their syntax.</p>
1360
1361</div>
1362
1363<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1364<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1365
1366<div class="doc_text">
1367
1368<dl>
1369 <dt><b>Boolean constants</b></dt>
1370
1371 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1372 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1373 </dd>
1374
1375 <dt><b>Integer constants</b></dt>
1376
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1377 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1378 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1379 integer types.
1380 </dd>
1381
1382 <dt><b>Floating point constants</b></dt>
1383
1384 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1385 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1386 notation (see below). Floating point constants must have a <a
1387 href="#t_floating">floating point</a> type. </dd>
1388
1389 <dt><b>Null pointer constants</b></dt>
1390
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1391 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1392 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1393
1394</dl>
1395
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1396<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1397of floating point constants. For example, the form '<tt>double
13980x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
13994.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1400(and the only time that they are generated by the disassembler) is when a
1401floating point constant must be emitted but it cannot be represented as a
1402decimal floating point number. For example, NaN's, infinities, and other
1403special values are represented in their IEEE hexadecimal format so that
1404assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1405
1406</div>
1407
1408<!-- ======================================================================= -->
1409<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1410</div>
1411
1412<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1413<p>Aggregate constants arise from aggregation of simple constants
1414and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1415
1416<dl>
1417 <dt><b>Structure constants</b></dt>
1418
1419 <dd>Structure constants are represented with notation similar to structure
1420 type definitions (a comma separated list of elements, surrounded by braces
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1421 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* %G }</tt>",
Chris Lattner3e63a9d2007-07-13 20:01:46 +0000[diff] [blame]1422 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]1423 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1424 types of elements must match those specified by the type.
1425 </dd>
1426
1427 <dt><b>Array constants</b></dt>
1428
1429 <dd>Array constants are represented with notation similar to array type
1430 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1431 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1432 constants must have <a href="#t_array">array type</a>, and the number and
1433 types of elements must match those specified by the type.
1434 </dd>
1435
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1436 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1437
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1438 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1439 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1440 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]1441 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1442 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1443 match those specified by the type.
1444 </dd>
1445
1446 <dt><b>Zero initialization</b></dt>
1447
1448 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1449 value to zero of <em>any</em> type, including scalar and aggregate types.
1450 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]1451 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1452 initializers.
1453 </dd>
1454</dl>
1455
1456</div>
1457
1458<!-- ======================================================================= -->
1459<div class="doc_subsection">
1460 <a name="globalconstants">Global Variable and Function Addresses</a>
1461</div>
1462
1463<div class="doc_text">
1464
1465<p>The addresses of <a href="#globalvars">global variables</a> and <a
1466href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1467constants. These constants are explicitly referenced when the <a
1468href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1469href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1470file:</p>
1471
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1472<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1473<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1474@X = global i32 17
1475@Y = global i32 42
1476@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1477</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1478</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1479
1480</div>
1481
1482<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1483<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1484<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1485 <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]1486 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1487 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1488
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1489 <p>Undefined values indicate to the compiler that the program is well defined
1490 no matter what value is used, giving the compiler more freedom to optimize.
1491 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1492</div>
1493
1494<!-- ======================================================================= -->
1495<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1496</div>
1497
1498<div class="doc_text">
1499
1500<p>Constant expressions are used to allow expressions involving other constants
1501to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1502href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1503that does not have side effects (e.g. load and call are not supported). The
1504following is the syntax for constant expressions:</p>
1505
1506<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1507 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1508 <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]1509 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1510
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1511 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1512 <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]1513 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]1514
1515 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1516 <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]1517 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]1518
1519 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1520 <dd>Truncate a floating point constant to another floating point type. The
1521 size of CST must be larger than the size of TYPE. Both types must be
1522 floating point.</dd>
1523
1524 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1525 <dd>Floating point extend a constant to another type. The size of CST must be
1526 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1527
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1528 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1529 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1530 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1531 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1532 of the same number of elements. If the value won't fit in the integer type,
1533 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1534
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1535 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1536 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1537 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1538 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1539 of the same number of elements. If the value won't fit in the integer type,
1540 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1541
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1542 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1543 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1544 constant. TYPE must be a scalar or vector floating point type. CST must be of
1545 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1546 of the same number of elements. If the value won't fit in the floating point
1547 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1548
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1549 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1550 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1551 constant. TYPE must be a scalar or vector floating point type. CST must be of
1552 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1553 of the same number of elements. If the value won't fit in the floating point
1554 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1555
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1556 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1557 <dd>Convert a pointer typed constant to the corresponding integer constant
1558 TYPE must be an integer type. CST must be of pointer type. The CST value is
1559 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1560
1561 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1562 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1563 pointer type. CST must be of integer type. The CST value is zero extended,
1564 truncated, or unchanged to make it fit in a pointer size. This one is
1565 <i>really</i> dangerous!</dd>
1566
1567 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1568 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1569 identical (same number of bits). The conversion is done as if the CST value
1570 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]1571 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1572 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]1573 pointers it is only valid to cast to another pointer type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1574 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1575
1576 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1577
1578 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1579 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1580 instruction, the index list may have zero or more indexes, which are required
1581 to make sense for the type of "CSTPTR".</dd>
1582
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1583 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1584
1585 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1586 constants.</dd>
1587
1588 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1589 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1590
1591 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1592 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1593
1594 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1595
1596 <dd>Perform the <a href="#i_extractelement">extractelement
1597 operation</a> on constants.
1598
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1599 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1600
1601 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1602 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1603
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1604
1605 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1606
1607 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1608 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1609
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1610 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1611
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1612 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1613 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1614 binary</a> operations. The constraints on operands are the same as those for
1615 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1616 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1617</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1618</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1619
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1620<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1621<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1622<!-- *********************************************************************** -->
1623
1624<!-- ======================================================================= -->
1625<div class="doc_subsection">
1626<a name="inlineasm">Inline Assembler Expressions</a>
1627</div>
1628
1629<div class="doc_text">
1630
1631<p>
1632LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1633Module-Level Inline Assembly</a>) through the use of a special value. This
1634value represents the inline assembler as a string (containing the instructions
1635to emit), a list of operand constraints (stored as a string), and a flag that
1636indicates whether or not the inline asm expression has side effects. An example
1637inline assembler expression is:
1638</p>
1639
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1640<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1641<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1642i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1643</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1644</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1645
1646<p>
1647Inline assembler expressions may <b>only</b> be used as the callee operand of
1648a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1649</p>
1650
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1651<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1652<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1653%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]1654</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1655</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1656
1657<p>
1658Inline asms with side effects not visible in the constraint list must be marked
1659as having side effects. This is done through the use of the
1660'<tt>sideeffect</tt>' keyword, like so:
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]1665call void asm sideeffect "eieio", ""()
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>TODO: The format of the asm and constraints string still need to be
1670documented here. Constraints on what can be done (e.g. duplication, moving, etc
1671need to be documented).
1672</p>
1673
1674</div>
1675
1676<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1677<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1678<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1679
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1680<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1681
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1682<p>The LLVM instruction set consists of several different
1683classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1684instructions</a>, <a href="#binaryops">binary instructions</a>,
1685<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1686 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1687instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1688
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1689</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1690
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1691<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1692<div class="doc_subsection"> <a name="terminators">Terminator
1693Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1694
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1695<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1696
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1697<p>As mentioned <a href="#functionstructure">previously</a>, every
1698basic block in a program ends with a "Terminator" instruction, which
1699indicates which block should be executed after the current block is
1700finished. These terminator instructions typically yield a '<tt>void</tt>'
1701value: they produce control flow, not values (the one exception being
1702the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1703<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1704 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1705instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1706the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1707 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1708 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1709
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1710</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1711
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1712<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1713<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1714Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1715<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1716<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1717<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]1718 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1719</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1720<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1721<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1722value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]1723<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1724returns a value and then causes control flow, and one that just causes
1725control flow to occur.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1726<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1727<p>The '<tt>ret</tt>' instruction may return any '<a
1728 href="#t_firstclass">first class</a>' type. Notice that a function is
1729not <a href="#wellformed">well formed</a> if there exists a '<tt>ret</tt>'
1730instruction inside of the function that returns a value that does not
1731match the return type of the function.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1732<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1733<p>When the '<tt>ret</tt>' instruction is executed, control flow
1734returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]1735 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1736the instruction after the call. If the caller was an "<a
1737 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1738at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1739returns a value, that value shall set the call or invoke instruction's
1740return value.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1741<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1742<pre> ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1743 ret void <i>; Return from a void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1744</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1745</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1746<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1747<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1748<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1749<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1750<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]1751</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1752<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1753<p>The '<tt>br</tt>' instruction is used to cause control flow to
1754transfer to a different basic block in the current function. There are
1755two forms of this instruction, corresponding to a conditional branch
1756and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1757<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1758<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1759single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1760unconditional form of the '<tt>br</tt>' instruction takes a single
1761'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1762<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1763<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1764argument is evaluated. If the value is <tt>true</tt>, control flows
1765to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1766control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1767<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1768<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]1769 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]1770</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1771<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1772<div class="doc_subsubsection">
1773 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1774</div>
1775
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1776<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1777<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1778
1779<pre>
1780 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1781</pre>
1782
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1783<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1784
1785<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1786several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1787instruction, allowing a branch to occur to one of many possible
1788destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1789
1790
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1791<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1792
1793<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1794comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1795an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1796table is not allowed to contain duplicate constant entries.</p>
1797
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1798<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1799
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1800<p>The <tt>switch</tt> instruction specifies a table of values and
1801destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1802table is searched for the given value. If the value is found, control flow is
1803transfered to the corresponding destination; otherwise, control flow is
1804transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1805
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1806<h5>Implementation:</h5>
1807
1808<p>Depending on properties of the target machine and the particular
1809<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1810ways. For example, it could be generated as a series of chained conditional
1811branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1812
1813<h5>Example:</h5>
1814
1815<pre>
1816 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1817 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1818 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1819
1820 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1821 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1822
1823 <i>; Implement a jump table:</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1824 switch i32 %val, label %otherwise [ i32 0, label %onzero
1825 i32 1, label %onone
1826 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1827</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1828</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1829
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1830<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1831<div class="doc_subsubsection">
1832 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
1833</div>
1834
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1835<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1836
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1837<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1838
1839<pre>
1840 &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]1841 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1842</pre>
1843
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]1844<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1845
1846<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
1847function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1848'<tt>normal</tt>' label or the
1849'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1850"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
1851"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1852href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
1853continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1854
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1855<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1856
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1857<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1858
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1859<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1860 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]1861 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1862 convention</a> the call should use. If none is specified, the call defaults
1863 to using C calling conventions.
1864 </li>
1865 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
1866 function value being invoked. In most cases, this is a direct function
1867 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
1868 an arbitrary pointer to function value.
1869 </li>
1870
1871 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
1872 function to be invoked. </li>
1873
1874 <li>'<tt>function args</tt>': argument list whose types match the function
1875 signature argument types. If the function signature indicates the function
1876 accepts a variable number of arguments, the extra arguments can be
1877 specified. </li>
1878
1879 <li>'<tt>normal label</tt>': the label reached when the called function
1880 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
1881
1882 <li>'<tt>exception label</tt>': the label reached when a callee returns with
1883 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
1884
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1885</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1886
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1887<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1888
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1889<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1890href="#i_call">call</a></tt>' instruction in most regards. The primary
1891difference is that it establishes an association with a label, which is used by
1892the runtime library to unwind the stack.</p>
1893
1894<p>This instruction is used in languages with destructors to ensure that proper
1895cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
1896exception. Additionally, this is important for implementation of
1897'<tt>catch</tt>' clauses in high-level languages that support them.</p>
1898
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1899<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1900<pre>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1901 %retval = invoke i32 %Test(i32 15) to label %Continue
1902 unwind label %TestCleanup <i>; {i32}:retval set</i>
1903 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Test(i32 15) to label %Continue
1904 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1905</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1906</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1907
1908
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1909<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1910
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1911<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
1912Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1913
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1914<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1915
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1916<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1917<pre>
1918 unwind
1919</pre>
1920
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1921<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1922
1923<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
1924at the first callee in the dynamic call stack which used an <a
1925href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
1926primarily used to implement exception handling.</p>
1927
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1928<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1929
1930<p>The '<tt>unwind</tt>' intrinsic causes execution of the current function to
1931immediately halt. The dynamic call stack is then searched for the first <a
1932href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
1933execution continues at the "exceptional" destination block specified by the
1934<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
1935dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1936</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1937
1938<!-- _______________________________________________________________________ -->
1939
1940<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
1941Instruction</a> </div>
1942
1943<div class="doc_text">
1944
1945<h5>Syntax:</h5>
1946<pre>
1947 unreachable
1948</pre>
1949
1950<h5>Overview:</h5>
1951
1952<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
1953instruction is used to inform the optimizer that a particular portion of the
1954code is not reachable. This can be used to indicate that the code after a
1955no-return function cannot be reached, and other facts.</p>
1956
1957<h5>Semantics:</h5>
1958
1959<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
1960</div>
1961
1962
1963
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1964<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1965<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1966<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1967<p>Binary operators are used to do most of the computation in a
1968program. They require two operands, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1969produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1970multiple 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]1971The result value of a binary operator is not
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1972necessarily the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1973<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1974</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1975<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1976<div class="doc_subsubsection"> <a name="i_add">'<tt>add</tt>'
1977Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1978<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1979<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1980<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]1981</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1982<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1983<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1984<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1985<p>The two arguments to the '<tt>add</tt>' instruction must be either <a
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1986 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a> values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1987 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]1988Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1989<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1990<p>The value produced is the integer or floating point sum of the two
1991operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1992<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1993<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]1994</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1995</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1996<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1997<div class="doc_subsubsection"> <a name="i_sub">'<tt>sub</tt>'
1998Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1999<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2000<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2001<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]2002</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2003<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2004<p>The '<tt>sub</tt>' instruction returns the difference of its two
2005operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2006<p>Note that the '<tt>sub</tt>' instruction is used to represent the '<tt>neg</tt>'
2007instruction present in most other intermediate representations.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2008<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2009<p>The two arguments to the '<tt>sub</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2010 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2011values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2012This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2013Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2014<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2015<p>The value produced is the integer or floating point difference of
2016the two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2017<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2018<pre>
2019 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2020 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2021</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2022</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2023<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2024<div class="doc_subsubsection"> <a name="i_mul">'<tt>mul</tt>'
2025Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2026<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2027<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2028<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]2029</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2030<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2031<p>The '<tt>mul</tt>' instruction returns the product of its two
2032operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2033<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2034<p>The two arguments to the '<tt>mul</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2035 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2036values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2037This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2038Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2039<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2040<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2041two operands.</p>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]2042<p>Because the operands are the same width, the result of an integer
2043multiplication is the same whether the operands should be deemed unsigned or
2044signed.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2045<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2046<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]2047</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2048</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2049<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2050<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2051</a></div>
2052<div class="doc_text">
2053<h5>Syntax:</h5>
2054<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2055</pre>
2056<h5>Overview:</h5>
2057<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2058operands.</p>
2059<h5>Arguments:</h5>
2060<p>The two arguments to the '<tt>udiv</tt>' instruction must be
2061<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2062types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2063of the values in which case the elements must be integers.</p>
2064<h5>Semantics:</h5>
2065<p>The value produced is the unsigned integer quotient of the two operands. This
2066instruction always performs an unsigned division operation, regardless of
2067whether the arguments are unsigned or not.</p>
2068<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2069<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]2070</pre>
2071</div>
2072<!-- _______________________________________________________________________ -->
2073<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2074</a> </div>
2075<div class="doc_text">
2076<h5>Syntax:</h5>
2077<pre> &lt;result&gt; = sdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2078</pre>
2079<h5>Overview:</h5>
2080<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2081operands.</p>
2082<h5>Arguments:</h5>
2083<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2084<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2085types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2086of the values in which case the elements must be integers.</p>
2087<h5>Semantics:</h5>
2088<p>The value produced is the signed integer quotient of the two operands. This
2089instruction always performs a signed division operation, regardless of whether
2090the arguments are signed or not.</p>
2091<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2092<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]2093</pre>
2094</div>
2095<!-- _______________________________________________________________________ -->
2096<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2097Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2098<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2099<h5>Syntax:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2100<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]2101</pre>
2102<h5>Overview:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2103<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2104operands.</p>
2105<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2106<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2107<a href="#t_floating">floating point</a> values. Both arguments must have
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2108identical types. This instruction can also take <a href="#t_vector">vector</a>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2109versions of floating point values.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2110<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2111<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2112<h5>Example:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2113<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]2114</pre>
2115</div>
2116<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2117<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2118</div>
2119<div class="doc_text">
2120<h5>Syntax:</h5>
2121<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2122</pre>
2123<h5>Overview:</h5>
2124<p>The '<tt>urem</tt>' instruction returns the remainder from the
2125unsigned division of its two arguments.</p>
2126<h5>Arguments:</h5>
2127<p>The two arguments to the '<tt>urem</tt>' instruction must be
2128<a href="#t_integer">integer</a> values. Both arguments must have identical
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2129types. This instruction can also take <a href="#t_vector">vector</a> versions
2130of the values in which case the elements must be integers.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2131<h5>Semantics:</h5>
2132<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
2133This instruction always performs an unsigned division to get the remainder,
2134regardless of whether the arguments are unsigned or not.</p>
2135<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2136<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]2137</pre>
2138
2139</div>
2140<!-- _______________________________________________________________________ -->
2141<div class="doc_subsubsection"> <a name="i_srem">'<tt>srem</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2142Instruction</a> </div>
2143<div class="doc_text">
2144<h5>Syntax:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2145<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]2146</pre>
2147<h5>Overview:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2148<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2149signed division of its two operands. This instruction can also take
2150<a href="#t_vector">vector</a> versions of the values in which case
2151the elements must be integers.</p>
2152</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2153<h5>Arguments:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2154<p>The two arguments to the '<tt>srem</tt>' instruction must be
2155<a href="#t_integer">integer</a> values. Both arguments must have identical
2156types.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2157<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2158<p>This instruction returns the <i>remainder</i> of a division (where the result
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2159has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
2160operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
2161a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2162 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2163Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2164please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2165Wikipedia: modulo operation</a>.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2166<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2167<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]2168</pre>
2169
2170</div>
2171<!-- _______________________________________________________________________ -->
2172<div class="doc_subsubsection"> <a name="i_frem">'<tt>frem</tt>'
2173Instruction</a> </div>
2174<div class="doc_text">
2175<h5>Syntax:</h5>
2176<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2177</pre>
2178<h5>Overview:</h5>
2179<p>The '<tt>frem</tt>' instruction returns the remainder from the
2180division of its two operands.</p>
2181<h5>Arguments:</h5>
2182<p>The two arguments to the '<tt>frem</tt>' instruction must be
2183<a href="#t_floating">floating point</a> values. Both arguments must have
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2184identical types. This instruction can also take <a href="#t_vector">vector</a>
2185versions of floating point values.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2186<h5>Semantics:</h5>
2187<p>This instruction returns the <i>remainder</i> of a division.</p>
2188<h5>Example:</h5>
2189<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]2190</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2191</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2192
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2193<!-- ======================================================================= -->
2194<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2195Operations</a> </div>
2196<div class="doc_text">
2197<p>Bitwise binary operators are used to do various forms of
2198bit-twiddling in a program. They are generally very efficient
2199instructions and can commonly be strength reduced from other
2200instructions. They require two operands, execute an operation on them,
2201and produce a single value. The resulting value of the bitwise binary
2202operators is always the same type as its first operand.</p>
2203</div>
2204
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2205<!-- _______________________________________________________________________ -->
2206<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2207Instruction</a> </div>
2208<div class="doc_text">
2209<h5>Syntax:</h5>
2210<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2211</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2212
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2213<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2214
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2215<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2216the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2217
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2218<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2219
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2220<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
2221 href="#t_integer">integer</a> type.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2222
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2223<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2224
2225<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup>. If
2226<tt>var2</tt> is (statically or dynamically) equal to or larger than the number
2227of bits in <tt>var1</tt>, the result is undefined.</p>
2228
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2229<h5>Example:</h5><pre>
2230 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2231 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2232 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2233 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2234</pre>
2235</div>
2236<!-- _______________________________________________________________________ -->
2237<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2238Instruction</a> </div>
2239<div class="doc_text">
2240<h5>Syntax:</h5>
2241<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2242</pre>
2243
2244<h5>Overview:</h5>
2245<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2246operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2247
2248<h5>Arguments:</h5>
2249<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
2250<a href="#t_integer">integer</a> type.</p>
2251
2252<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2253
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2254<p>This instruction always performs a logical shift right operation. The most
2255significant bits of the result will be filled with zero bits after the
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2256shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
2257the number of bits in <tt>var1</tt>, the result is undefined.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2258
2259<h5>Example:</h5>
2260<pre>
2261 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2262 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2263 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2264 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2265 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2266</pre>
2267</div>
2268
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2269<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2270<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2271Instruction</a> </div>
2272<div class="doc_text">
2273
2274<h5>Syntax:</h5>
2275<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2276</pre>
2277
2278<h5>Overview:</h5>
2279<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2280operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2281
2282<h5>Arguments:</h5>
2283<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
2284<a href="#t_integer">integer</a> type.</p>
2285
2286<h5>Semantics:</h5>
2287<p>This instruction always performs an arithmetic shift right operation,
2288The most significant bits of the result will be filled with the sign bit
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2289of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
2290larger than the number of bits in <tt>var1</tt>, the result is undefined.
2291</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2292
2293<h5>Example:</h5>
2294<pre>
2295 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2296 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2297 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2298 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2299 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2300</pre>
2301</div>
2302
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2303<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2304<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2305Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2306<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2307<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2308<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]2309</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2310<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2311<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2312its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2313<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2314<p>The two arguments to the '<tt>and</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2315 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2316identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2317<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2318<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2319<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2320<div style="align: center">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2321<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2322 <tbody>
2323 <tr>
2324 <td>In0</td>
2325 <td>In1</td>
2326 <td>Out</td>
2327 </tr>
2328 <tr>
2329 <td>0</td>
2330 <td>0</td>
2331 <td>0</td>
2332 </tr>
2333 <tr>
2334 <td>0</td>
2335 <td>1</td>
2336 <td>0</td>
2337 </tr>
2338 <tr>
2339 <td>1</td>
2340 <td>0</td>
2341 <td>0</td>
2342 </tr>
2343 <tr>
2344 <td>1</td>
2345 <td>1</td>
2346 <td>1</td>
2347 </tr>
2348 </tbody>
2349</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2350</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2351<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2352<pre> &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
2353 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2354 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2355</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2356</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2357<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2358<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2359<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2360<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2361<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]2362</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2363<h5>Overview:</h5>
2364<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2365or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2366<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2367<p>The two arguments to the '<tt>or</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2368 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2369identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2370<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2371<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2372<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2373<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2374<table border="1" cellspacing="0" cellpadding="4">
2375 <tbody>
2376 <tr>
2377 <td>In0</td>
2378 <td>In1</td>
2379 <td>Out</td>
2380 </tr>
2381 <tr>
2382 <td>0</td>
2383 <td>0</td>
2384 <td>0</td>
2385 </tr>
2386 <tr>
2387 <td>0</td>
2388 <td>1</td>
2389 <td>1</td>
2390 </tr>
2391 <tr>
2392 <td>1</td>
2393 <td>0</td>
2394 <td>1</td>
2395 </tr>
2396 <tr>
2397 <td>1</td>
2398 <td>1</td>
2399 <td>1</td>
2400 </tr>
2401 </tbody>
2402</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2403</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2404<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2405<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2406 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2407 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2408</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2409</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2410<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2411<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2412Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2413<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2414<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2415<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]2416</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2417<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2418<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2419or of its two operands. The <tt>xor</tt> is used to implement the
2420"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2421<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2422<p>The two arguments to the '<tt>xor</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2423 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2424identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2425<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2426<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2427<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2428<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2429<table border="1" cellspacing="0" cellpadding="4">
2430 <tbody>
2431 <tr>
2432 <td>In0</td>
2433 <td>In1</td>
2434 <td>Out</td>
2435 </tr>
2436 <tr>
2437 <td>0</td>
2438 <td>0</td>
2439 <td>0</td>
2440 </tr>
2441 <tr>
2442 <td>0</td>
2443 <td>1</td>
2444 <td>1</td>
2445 </tr>
2446 <tr>
2447 <td>1</td>
2448 <td>0</td>
2449 <td>1</td>
2450 </tr>
2451 <tr>
2452 <td>1</td>
2453 <td>1</td>
2454 <td>0</td>
2455 </tr>
2456 </tbody>
2457</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2458</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2459<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2460<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2461<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2462 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2463 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2464 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2465</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2466</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2467
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2468<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2469<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2470 <a name="vectorops">Vector Operations</a>
2471</div>
2472
2473<div class="doc_text">
2474
2475<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2476target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2477vector-specific operations needed to process vectors effectively. While LLVM
2478does directly support these vector operations, many sophisticated algorithms
2479will want to use target-specific intrinsics to take full advantage of a specific
2480target.</p>
2481
2482</div>
2483
2484<!-- _______________________________________________________________________ -->
2485<div class="doc_subsubsection">
2486 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2487</div>
2488
2489<div class="doc_text">
2490
2491<h5>Syntax:</h5>
2492
2493<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2494 &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]2495</pre>
2496
2497<h5>Overview:</h5>
2498
2499<p>
2500The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2501element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2502</p>
2503
2504
2505<h5>Arguments:</h5>
2506
2507<p>
2508The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2509value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2510an index indicating the position from which to extract the element.
2511The index may be a variable.</p>
2512
2513<h5>Semantics:</h5>
2514
2515<p>
2516The result is a scalar of the same type as the element type of
2517<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2518<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2519results are undefined.
2520</p>
2521
2522<h5>Example:</h5>
2523
2524<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2525 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2526</pre>
2527</div>
2528
2529
2530<!-- _______________________________________________________________________ -->
2531<div class="doc_subsubsection">
2532 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2533</div>
2534
2535<div class="doc_text">
2536
2537<h5>Syntax:</h5>
2538
2539<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2540 &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]2541</pre>
2542
2543<h5>Overview:</h5>
2544
2545<p>
2546The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2547element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2548</p>
2549
2550
2551<h5>Arguments:</h5>
2552
2553<p>
2554The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2555value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2556scalar value whose type must equal the element type of the first
2557operand. The third operand is an index indicating the position at
2558which to insert the value. The index may be a variable.</p>
2559
2560<h5>Semantics:</h5>
2561
2562<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2563The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2564element values are those of <tt>val</tt> except at position
2565<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2566exceeds the length of <tt>val</tt>, the results are undefined.
2567</p>
2568
2569<h5>Example:</h5>
2570
2571<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2572 %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]2573</pre>
2574</div>
2575
2576<!-- _______________________________________________________________________ -->
2577<div class="doc_subsubsection">
2578 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2579</div>
2580
2581<div class="doc_text">
2582
2583<h5>Syntax:</h5>
2584
2585<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2586 &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]2587</pre>
2588
2589<h5>Overview:</h5>
2590
2591<p>
2592The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2593from two input vectors, returning a vector of the same type.
2594</p>
2595
2596<h5>Arguments:</h5>
2597
2598<p>
2599The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2600with types that match each other and types that match the result of the
2601instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2602of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2603</p>
2604
2605<p>
2606The shuffle mask operand is required to be a constant vector with either
2607constant integer or undef values.
2608</p>
2609
2610<h5>Semantics:</h5>
2611
2612<p>
2613The elements of the two input vectors are numbered from left to right across
2614both of the vectors. The shuffle mask operand specifies, for each element of
2615the result vector, which element of the two input registers the result element
2616gets. The element selector may be undef (meaning "don't care") and the second
2617operand may be undef if performing a shuffle from only one vector.
2618</p>
2619
2620<h5>Example:</h5>
2621
2622<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2623 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2624 &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]2625 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2626 &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]2627</pre>
2628</div>
2629
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]2630
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2631<!-- ======================================================================= -->
2632<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2633 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2634</div>
2635
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2636<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2637
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2638<p>A key design point of an SSA-based representation is how it
2639represents memory. In LLVM, no memory locations are in SSA form, which
2640makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2641allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2642
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2643</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2644
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2645<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2646<div class="doc_subsubsection">
2647 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
2648</div>
2649
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2650<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2651
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2652<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2653
2654<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2655 &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]2656</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2657
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2658<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2659
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2660<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]2661heap and returns a pointer to it. The object is always allocated in the generic
2662address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2663
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2664<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2665
2666<p>The '<tt>malloc</tt>' instruction allocates
2667<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]2668bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2669appropriate type to the program. If "NumElements" is specified, it is the
2670number of elements allocated. If an alignment is specified, the value result
2671of the allocation is guaranteed to be aligned to at least that boundary. If
2672not specified, or if zero, the target can choose to align the allocation on any
2673convenient boundary.</p>
2674
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2675<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2676
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2677<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2678
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2679<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
2680a pointer is returned.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2681
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2682<h5>Example:</h5>
2683
2684<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2685 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2686
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2687 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
2688 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
2689 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
2690 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
2691 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2692</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2693</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2694
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2695<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2696<div class="doc_subsubsection">
2697 <a name="i_free">'<tt>free</tt>' Instruction</a>
2698</div>
2699
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2700<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2701
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2702<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2703
2704<pre>
2705 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2706</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2707
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2708<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2709
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2710<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2711memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2712
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2713<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2714
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2715<p>'<tt>value</tt>' shall be a pointer value that points to a value
2716that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
2717instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2718
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2719<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2720
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2721<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2722after this instruction executes.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2723
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2724<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2725
2726<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2727 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
2728 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2729</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2730</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2731
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2732<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2733<div class="doc_subsubsection">
2734 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
2735</div>
2736
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2737<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2738
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2739<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2740
2741<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2742 &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]2743</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2744
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2745<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2746
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2747<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
2748currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]2749returns to its caller. The object is always allocated in the generic address
2750space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2751
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2752<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2753
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2754<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2755bytes of memory on the runtime stack, returning a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2756appropriate type to the program. If "NumElements" is specified, it is the
2757number of elements allocated. If an alignment is specified, the value result
2758of the allocation is guaranteed to be aligned to at least that boundary. If
2759not specified, or if zero, the target can choose to align the allocation on any
2760convenient boundary.</p>
2761
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2762<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2763
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2764<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2765
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2766<p>Memory is allocated; a pointer is returned. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2767memory is automatically released when the function returns. The '<tt>alloca</tt>'
2768instruction is commonly used to represent automatic variables that must
2769have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]2770 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]2771instructions), the memory is reclaimed.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2772
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2773<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2774
2775<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2776 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2777 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
2778 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2779 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2780</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2781</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2782
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2783<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2784<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
2785Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2786<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2787<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2788<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]2789<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2790<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2791<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2792<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2793address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]2794 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2795marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2796the number or order of execution of this <tt>load</tt> with other
2797volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
2798instructions. </p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2799<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2800<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2801<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2802<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2803 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2804 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
2805 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2806</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2807</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2808<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2809<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
2810Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]2811<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2812<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2813<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
2814 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]2815</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2816<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2817<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2818<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2819<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2820to 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]2821operand must be a pointer to the type of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2822operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2823optimizer is not allowed to modify the number or order of execution of
2824this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
2825 href="#i_store">store</a></tt> instructions.</p>
2826<h5>Semantics:</h5>
2827<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
2828at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2829<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2830<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]2831 store i32 3, i32* %ptr <i>; yields {void}</i>
2832 %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]2833</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2834</div>
2835
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2836<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2837<div class="doc_subsubsection">
2838 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
2839</div>
2840
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2841<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2842<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2843<pre>
2844 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
2845</pre>
2846
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2847<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2848
2849<p>
2850The '<tt>getelementptr</tt>' instruction is used to get the address of a
2851subelement of an aggregate data structure.</p>
2852
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2853<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2854
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2855<p>This instruction takes a list of integer operands that indicate what
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2856elements of the aggregate object to index to. The actual types of the arguments
2857provided depend on the type of the first pointer argument. The
2858'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]2859levels 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]2860structure, only <tt>i32</tt> integer constants are allowed. When indexing
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2861into an array or pointer, only integers of 32 or 64 bits are allowed, and will
2862be sign extended to 64-bit values.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2863
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2864<p>For example, let's consider a C code fragment and how it gets
2865compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2866
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2867<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2868<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2869struct RT {
2870 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2871 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2872 char C;
2873};
2874struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2875 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2876 double Y;
2877 struct RT Z;
2878};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2879
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2880int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2881 return &amp;s[1].Z.B[5][13];
2882}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2883</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2884</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2885
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2886<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2887
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2888<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2889<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2890%RT = type { i8 , [10 x [20 x i32]], i8 }
2891%ST = type { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2892
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2893define i32* %foo(%ST* %s) {
2894entry:
2895 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
2896 ret i32* %reg
2897}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2898</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2899</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2900
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2901<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2902
2903<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2904on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2905and <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]2906<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]2907to 64-bits. <a href="#t_struct">Structure</a> types require <tt>i32</tt>
Reid Spencer42ddd842006-12-03 16:53:48 +0000[diff] [blame]2908<b>constants</b>.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2909
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2910<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]2911type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2912}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2913the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
2914i8 }</tt>' type, another structure. The third index indexes into the second
2915element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2916array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2917'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
2918to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2919
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2920<p>Note that it is perfectly legal to index partially through a
2921structure, returning a pointer to an inner element. Because of this,
2922the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2923
2924<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2925 define i32* %foo(%ST* %s) {
2926 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2927 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
2928 %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]2929 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
2930 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
2931 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2932 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2933</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2934
2935<p>Note that it is undefined to access an array out of bounds: array and
2936pointer indexes must always be within the defined bounds of the array type.
2937The one exception for this rules is zero length arrays. These arrays are
2938defined to be accessible as variable length arrays, which requires access
2939beyond the zero'th element.</p>
2940
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2941<p>The getelementptr instruction is often confusing. For some more insight
2942into how it works, see <a href="GetElementPtr.html">the getelementptr
2943FAQ</a>.</p>
2944
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2945<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2946
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2947<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2948 <i>; yields [12 x i8]*:aptr</i>
2949 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2950</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2951</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2952
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2953<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]2954<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2955</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2956<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]2957<p>The instructions in this category are the conversion instructions (casting)
2958which all take a single operand and a type. They perform various bit conversions
2959on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2960</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]2961
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2962<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]2963<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2964 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
2965</div>
2966<div class="doc_text">
2967
2968<h5>Syntax:</h5>
2969<pre>
2970 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2971</pre>
2972
2973<h5>Overview:</h5>
2974<p>
2975The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
2976</p>
2977
2978<h5>Arguments:</h5>
2979<p>
2980The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
2981be 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]2982and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2983type. The bit size of <tt>value</tt> must be larger than the bit size of
2984<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2985
2986<h5>Semantics:</h5>
2987<p>
2988The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2989and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
2990larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
2991It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2992
2993<h5>Example:</h5>
2994<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2995 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2996 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
2997 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2998</pre>
2999</div>
3000
3001<!-- _______________________________________________________________________ -->
3002<div class="doc_subsubsection">
3003 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3004</div>
3005<div class="doc_text">
3006
3007<h5>Syntax:</h5>
3008<pre>
3009 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3010</pre>
3011
3012<h5>Overview:</h5>
3013<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3014<tt>ty2</tt>.</p>
3015
3016
3017<h5>Arguments:</h5>
3018<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]3019<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3020also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3021<tt>value</tt> must be smaller than the bit size of the destination type,
3022<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3023
3024<h5>Semantics:</h5>
3025<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]3026bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3027
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3028<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]3029
3030<h5>Example:</h5>
3031<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3032 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3033 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3034</pre>
3035</div>
3036
3037<!-- _______________________________________________________________________ -->
3038<div class="doc_subsubsection">
3039 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3040</div>
3041<div class="doc_text">
3042
3043<h5>Syntax:</h5>
3044<pre>
3045 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3046</pre>
3047
3048<h5>Overview:</h5>
3049<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3050
3051<h5>Arguments:</h5>
3052<p>
3053The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3054<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3055also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3056<tt>value</tt> must be smaller than the bit size of the destination type,
3057<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3058
3059<h5>Semantics:</h5>
3060<p>
3061The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3062bit (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]3063the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3064
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3065<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]3066
3067<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3068<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3069 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3070 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3071</pre>
3072</div>
3073
3074<!-- _______________________________________________________________________ -->
3075<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3076 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3077</div>
3078
3079<div class="doc_text">
3080
3081<h5>Syntax:</h5>
3082
3083<pre>
3084 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3085</pre>
3086
3087<h5>Overview:</h5>
3088<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3089<tt>ty2</tt>.</p>
3090
3091
3092<h5>Arguments:</h5>
3093<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3094 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3095cast it to. The size of <tt>value</tt> must be larger than the size of
3096<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3097<i>no-op cast</i>.</p>
3098
3099<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3100<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3101<a href="#t_floating">floating point</a> type to a smaller
3102<a href="#t_floating">floating point</a> type. If the value cannot fit within
3103the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3104
3105<h5>Example:</h5>
3106<pre>
3107 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3108 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3109</pre>
3110</div>
3111
3112<!-- _______________________________________________________________________ -->
3113<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3114 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3115</div>
3116<div class="doc_text">
3117
3118<h5>Syntax:</h5>
3119<pre>
3120 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3121</pre>
3122
3123<h5>Overview:</h5>
3124<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3125floating point value.</p>
3126
3127<h5>Arguments:</h5>
3128<p>The '<tt>fpext</tt>' instruction takes a
3129<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3130and a <a href="#t_floating">floating point</a> type to cast it to. The source
3131type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3132
3133<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3134<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3135<a href="#t_floating">floating point</a> type to a larger
3136<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3137used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3138<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]3139
3140<h5>Example:</h5>
3141<pre>
3142 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3143 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3144</pre>
3145</div>
3146
3147<!-- _______________________________________________________________________ -->
3148<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3149 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3150</div>
3151<div class="doc_text">
3152
3153<h5>Syntax:</h5>
3154<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3155 &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]3156</pre>
3157
3158<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3159<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3160unsigned integer equivalent of type <tt>ty2</tt>.
3161</p>
3162
3163<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3164<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]3165scalar or vector <a href="#t_floating">floating point</a> value, and a type
3166to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3167type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3168vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3169
3170<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3171<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3172<a href="#t_floating">floating point</a> operand into the nearest (rounding
3173towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3174the results are undefined.</p>
3175
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3176<h5>Example:</h5>
3177<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3178 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3179 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3180 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3181</pre>
3182</div>
3183
3184<!-- _______________________________________________________________________ -->
3185<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3186 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3187</div>
3188<div class="doc_text">
3189
3190<h5>Syntax:</h5>
3191<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3192 &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]3193</pre>
3194
3195<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3196<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3197<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]3198</p>
3199
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3200<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3201<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]3202scalar or vector <a href="#t_floating">floating point</a> value, and a type
3203to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3204type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3205vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3206
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3207<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3208<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3209<a href="#t_floating">floating point</a> operand into the nearest (rounding
3210towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3211the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3212
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3213<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3214<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3215 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3216 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3217 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3218</pre>
3219</div>
3220
3221<!-- _______________________________________________________________________ -->
3222<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3223 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3224</div>
3225<div class="doc_text">
3226
3227<h5>Syntax:</h5>
3228<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3229 &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]3230</pre>
3231
3232<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3233<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3234integer and converts that value to the <tt>ty2</tt> type.</p>
3235
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3236<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3237<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3238scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3239to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3240type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3241floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3242
3243<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3244<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3245integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3246the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3247
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3248<h5>Example:</h5>
3249<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3250 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3251 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3252</pre>
3253</div>
3254
3255<!-- _______________________________________________________________________ -->
3256<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3257 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3258</div>
3259<div class="doc_text">
3260
3261<h5>Syntax:</h5>
3262<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3263 &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]3264</pre>
3265
3266<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3267<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3268integer and converts that value to the <tt>ty2</tt> type.</p>
3269
3270<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3271<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3272scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3273to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3274type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3275floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3276
3277<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3278<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3279integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3280the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3281
3282<h5>Example:</h5>
3283<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3284 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3285 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3286</pre>
3287</div>
3288
3289<!-- _______________________________________________________________________ -->
3290<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3291 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3292</div>
3293<div class="doc_text">
3294
3295<h5>Syntax:</h5>
3296<pre>
3297 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3298</pre>
3299
3300<h5>Overview:</h5>
3301<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3302the integer type <tt>ty2</tt>.</p>
3303
3304<h5>Arguments:</h5>
3305<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3306must 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]3307<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3308
3309<h5>Semantics:</h5>
3310<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3311<tt>ty2</tt> by interpreting the pointer value as an integer and either
3312truncating or zero extending that value to the size of the integer type. If
3313<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3314<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]3315are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3316change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3317
3318<h5>Example:</h5>
3319<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3320 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3321 %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]3322</pre>
3323</div>
3324
3325<!-- _______________________________________________________________________ -->
3326<div class="doc_subsubsection">
3327 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3328</div>
3329<div class="doc_text">
3330
3331<h5>Syntax:</h5>
3332<pre>
3333 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3334</pre>
3335
3336<h5>Overview:</h5>
3337<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3338a pointer type, <tt>ty2</tt>.</p>
3339
3340<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3341<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3342value to cast, and a type to cast it to, which must be a
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]3343<a href="#t_pointer">pointer</a> type.
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3344
3345<h5>Semantics:</h5>
3346<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3347<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3348the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3349size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3350the size of a pointer then a zero extension is done. If they are the same size,
3351nothing is done (<i>no-op cast</i>).</p>
3352
3353<h5>Example:</h5>
3354<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3355 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3356 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3357 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3358</pre>
3359</div>
3360
3361<!-- _______________________________________________________________________ -->
3362<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3363 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3364</div>
3365<div class="doc_text">
3366
3367<h5>Syntax:</h5>
3368<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3369 &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]3370</pre>
3371
3372<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3373<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3374<tt>ty2</tt> without changing any bits.</p>
3375
3376<h5>Arguments:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3377<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3378a first class value, and a type to cast it to, which must also be a <a
3379 href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]3380and the destination type, <tt>ty2</tt>, must be identical. If the source
3381type is a pointer, the destination type must also be a pointer.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3382
3383<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3384<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3385<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3386this conversion. The conversion is done as if the <tt>value</tt> had been
3387stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3388converted to other pointer types with this instruction. To convert pointers to
3389other types, use the <a href="#i_inttoptr">inttoptr</a> or
3390<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3391
3392<h5>Example:</h5>
3393<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3394 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3395 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3396 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3397</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3398</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3399
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3400<!-- ======================================================================= -->
3401<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3402<div class="doc_text">
3403<p>The instructions in this category are the "miscellaneous"
3404instructions, which defy better classification.</p>
3405</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3406
3407<!-- _______________________________________________________________________ -->
3408<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3409</div>
3410<div class="doc_text">
3411<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3412<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]3413</pre>
3414<h5>Overview:</h5>
3415<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
3416of its two integer operands.</p>
3417<h5>Arguments:</h5>
3418<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3419the condition code indicating the kind of comparison to perform. It is not
3420a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3421<ol>
3422 <li><tt>eq</tt>: equal</li>
3423 <li><tt>ne</tt>: not equal </li>
3424 <li><tt>ugt</tt>: unsigned greater than</li>
3425 <li><tt>uge</tt>: unsigned greater or equal</li>
3426 <li><tt>ult</tt>: unsigned less than</li>
3427 <li><tt>ule</tt>: unsigned less or equal</li>
3428 <li><tt>sgt</tt>: signed greater than</li>
3429 <li><tt>sge</tt>: signed greater or equal</li>
3430 <li><tt>slt</tt>: signed less than</li>
3431 <li><tt>sle</tt>: signed less or equal</li>
3432</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3433<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3434<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3435<h5>Semantics:</h5>
3436<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3437the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3438yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3439<ol>
3440 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3441 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3442 </li>
3443 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3444 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3445 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
3446 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3447 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
3448 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3449 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
3450 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3451 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
3452 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
3453 <li><tt>sgt</tt>: interprets the operands as signed values and yields
3454 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3455 <li><tt>sge</tt>: interprets the operands as signed values and yields
3456 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3457 <li><tt>slt</tt>: interprets the operands as signed values and yields
3458 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3459 <li><tt>sle</tt>: interprets the operands as signed values and yields
3460 <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]3461</ol>
3462<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3463values are compared as if they were integers.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3464
3465<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3466<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3467 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3468 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3469 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3470 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3471 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3472</pre>
3473</div>
3474
3475<!-- _______________________________________________________________________ -->
3476<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3477</div>
3478<div class="doc_text">
3479<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3480<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]3481</pre>
3482<h5>Overview:</h5>
3483<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
3484of its floating point operands.</p>
3485<h5>Arguments:</h5>
3486<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3487the condition code indicating the kind of comparison to perform. It is not
3488a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3489<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3490 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3491 <li><tt>oeq</tt>: ordered and equal</li>
3492 <li><tt>ogt</tt>: ordered and greater than </li>
3493 <li><tt>oge</tt>: ordered and greater than or equal</li>
3494 <li><tt>olt</tt>: ordered and less than </li>
3495 <li><tt>ole</tt>: ordered and less than or equal</li>
3496 <li><tt>one</tt>: ordered and not equal</li>
3497 <li><tt>ord</tt>: ordered (no nans)</li>
3498 <li><tt>ueq</tt>: unordered or equal</li>
3499 <li><tt>ugt</tt>: unordered or greater than </li>
3500 <li><tt>uge</tt>: unordered or greater than or equal</li>
3501 <li><tt>ult</tt>: unordered or less than </li>
3502 <li><tt>ule</tt>: unordered or less than or equal</li>
3503 <li><tt>une</tt>: unordered or not equal</li>
3504 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3505 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3506</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3507<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]3508<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3509<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
3510<a href="#t_floating">floating point</a> typed. They must have identical
3511types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3512<h5>Semantics:</h5>
3513<p>The '<tt>fcmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3514the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3515yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3516<ol>
3517 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3518 <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]3519 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3520 <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]3521 <tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3522 <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]3523 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3524 <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]3525 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3526 <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]3527 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3528 <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]3529 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3530 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3531 <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]3532 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3533 <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]3534 <tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3535 <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]3536 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3537 <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]3538 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3539 <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]3540 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3541 <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]3542 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3543 <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]3544 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
3545</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3546
3547<h5>Example:</h5>
3548<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
3549 &lt;result&gt; = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
3550 &lt;result&gt; = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
3551 &lt;result&gt; = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
3552</pre>
3553</div>
3554
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3555<!-- _______________________________________________________________________ -->
3556<div class="doc_subsubsection"> <a name="i_phi">'<tt>phi</tt>'
3557Instruction</a> </div>
3558<div class="doc_text">
3559<h5>Syntax:</h5>
3560<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
3561<h5>Overview:</h5>
3562<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
3563the SSA graph representing the function.</p>
3564<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3565<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3566field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
3567as arguments, with one pair for each predecessor basic block of the
3568current block. Only values of <a href="#t_firstclass">first class</a>
3569type may be used as the value arguments to the PHI node. Only labels
3570may be used as the label arguments.</p>
3571<p>There must be no non-phi instructions between the start of a basic
3572block and the PHI instructions: i.e. PHI instructions must be first in
3573a basic block.</p>
3574<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3575<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
3576specified by the pair corresponding to the predecessor basic block that executed
3577just prior to the current block.</p>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3578<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3579<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]3580</div>
3581
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3582<!-- _______________________________________________________________________ -->
3583<div class="doc_subsubsection">
3584 <a name="i_select">'<tt>select</tt>' Instruction</a>
3585</div>
3586
3587<div class="doc_text">
3588
3589<h5>Syntax:</h5>
3590
3591<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3592 &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]3593</pre>
3594
3595<h5>Overview:</h5>
3596
3597<p>
3598The '<tt>select</tt>' instruction is used to choose one value based on a
3599condition, without branching.
3600</p>
3601
3602
3603<h5>Arguments:</h5>
3604
3605<p>
3606The '<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.
3607</p>
3608
3609<h5>Semantics:</h5>
3610
3611<p>
3612If the boolean condition evaluates to true, the instruction returns the first
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3613value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3614</p>
3615
3616<h5>Example:</h5>
3617
3618<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3619 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3620</pre>
3621</div>
3622
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]3623
3624<!-- _______________________________________________________________________ -->
3625<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3626 <a name="i_call">'<tt>call</tt>' Instruction</a>
3627</div>
3628
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3629<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3630
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3631<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3632<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3633 &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]3634</pre>
3635
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3636<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3637
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3638<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3639
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3640<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3641
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3642<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3643
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3644<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3645 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3646 <p>The optional "tail" marker indicates whether the callee function accesses
3647 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3648 function call is eligible for tail call optimization. Note that calls may
3649 be marked "tail" even if they do not occur before a <a
3650 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3651 </li>
3652 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3653 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3654 convention</a> the call should use. If none is specified, the call defaults
3655 to using C calling conventions.
3656 </li>
3657 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3658 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
3659 the type of the return value. Functions that return no value are marked
3660 <tt><a href="#t_void">void</a></tt>.</p>
3661 </li>
3662 <li>
3663 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
3664 value being invoked. The argument types must match the types implied by
3665 this signature. This type can be omitted if the function is not varargs
3666 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3667 </li>
3668 <li>
3669 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
3670 be invoked. In most cases, this is a direct function invocation, but
3671 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3672 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3673 </li>
3674 <li>
3675 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]3676 function signature argument types. All arguments must be of
3677 <a href="#t_firstclass">first class</a> type. If the function signature
3678 indicates the function accepts a variable number of arguments, the extra
3679 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3680 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3681</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3682
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3683<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3684
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3685<p>The '<tt>call</tt>' instruction is used to cause control flow to
3686transfer to a specified function, with its incoming arguments bound to
3687the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
3688instruction in the called function, control flow continues with the
3689instruction after the function call, and the return value of the
3690function is bound to the result argument. This is a simpler case of
3691the <a href="#i_invoke">invoke</a> instruction.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3692
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3693<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3694
3695<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3696 %retval = call i32 @test(i32 %argc)
3697 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42);
3698 %X = tail call i32 @foo()
3699 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo()
3700 %Z = call void %foo(i8 97 signext)
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3701</pre>
3702
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3703</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3704
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3705<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3706<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3707 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3708</div>
3709
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3710<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3711
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3712<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3713
3714<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3715 &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]3716</pre>
3717
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3718<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3719
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3720<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3721the "variable argument" area of a function call. It is used to implement the
3722<tt>va_arg</tt> macro in C.</p>
3723
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3724<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3725
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3726<p>This instruction takes a <tt>va_list*</tt> value and the type of
3727the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3728increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3729actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3730
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3731<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3732
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3733<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
3734type from the specified <tt>va_list</tt> and causes the
3735<tt>va_list</tt> to point to the next argument. For more information,
3736see the variable argument handling <a href="#int_varargs">Intrinsic
3737Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3738
3739<p>It is legal for this instruction to be called in a function which does not
3740take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3741function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3742
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3743<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3744href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3745argument.</p>
3746
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3747<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3748
3749<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
3750
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3751</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3752
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3753<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3754<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
3755<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3756
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3757<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3758
3759<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3760well known names and semantics and are required to follow certain restrictions.
3761Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3762language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]3763adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3764
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3765<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3766prefix is reserved in LLVM for intrinsic names; thus, function names may not
3767begin with this prefix. Intrinsic functions must always be external functions:
3768you cannot define the body of intrinsic functions. Intrinsic functions may
3769only be used in call or invoke instructions: it is illegal to take the address
3770of an intrinsic function. Additionally, because intrinsic functions are part
3771of the LLVM language, it is required if any are added that they be documented
3772here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3773
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]3774<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
3775a family of functions that perform the same operation but on different data
3776types. Because LLVM can represent over 8 million different integer types,
3777overloading is used commonly to allow an intrinsic function to operate on any
3778integer type. One or more of the argument types or the result type can be
3779overloaded to accept any integer type. Argument types may also be defined as
3780exactly matching a previous argument's type or the result type. This allows an
3781intrinsic function which accepts multiple arguments, but needs all of them to
3782be of the same type, to only be overloaded with respect to a single argument or
3783the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3784
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]3785<p>Overloaded intrinsics will have the names of its overloaded argument types
3786encoded into its function name, each preceded by a period. Only those types
3787which are overloaded result in a name suffix. Arguments whose type is matched
3788against another type do not. For example, the <tt>llvm.ctpop</tt> function can
3789take an integer of any width and returns an integer of exactly the same integer
3790width. This leads to a family of functions such as
3791<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
3792Only one type, the return type, is overloaded, and only one type suffix is
3793required. Because the argument's type is matched against the return type, it
3794does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3795
3796<p>To learn how to add an intrinsic function, please see the
3797<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3798</p>
3799
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3800</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3801
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3802<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3803<div class="doc_subsection">
3804 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
3805</div>
3806
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3807<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3808
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3809<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3810 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3811intrinsic functions. These functions are related to the similarly
3812named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3813
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3814<p>All of these functions operate on arguments that use a
3815target-specific value type "<tt>va_list</tt>". The LLVM assembly
3816language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3817transformations should be prepared to handle these functions regardless of
3818the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3819
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]3820<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]3821instruction and the variable argument handling intrinsic functions are
3822used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3823
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3824<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3825<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3826define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3827 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3828 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3829 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3830 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3831
3832 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3833 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3834
3835 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3836 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3837 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3838 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3839 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3840
3841 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3842 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3843 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3844}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3845
3846declare void @llvm.va_start(i8*)
3847declare void @llvm.va_copy(i8*, i8*)
3848declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3849</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3850</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3851
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3852</div>
3853
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3854<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3855<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3856 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3857</div>
3858
3859
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3860<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3861<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3862<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3863<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3864<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
3865<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
3866href="#i_va_arg">va_arg</a></tt>.</p>
3867
3868<h5>Arguments:</h5>
3869
3870<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
3871
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3872<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3873
3874<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
3875macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3876<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]3877<tt>va_arg</tt> will produce the first variable argument passed to the function.
3878Unlike 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]3879last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3880
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3881</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3882
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3883<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3884<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3885 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3886</div>
3887
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3888<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3889<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3890<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3891<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3892
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3893<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3894which 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]3895or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3896
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3897<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3898
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3899<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]3900
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3901<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3902
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3903<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]3904macro available in C. In a target-dependent way, it destroys the
3905<tt>va_list</tt> element to which the argument points. Calls to <a
3906href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
3907<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
3908<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3909
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3910</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3911
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3912<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3913<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3914 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3915</div>
3916
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3917<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3918
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3919<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3920
3921<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3922 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3923</pre>
3924
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3925<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3926
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3927<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
3928from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3929
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3930<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3931
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3932<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]3933The 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]3934
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3935
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3936<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3937
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3938<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
3939macro available in C. In a target-dependent way, it copies the source
3940<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
3941intrinsic is necessary because the <tt><a href="#int_va_start">
3942llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
3943example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3944
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3945</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3946
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3947<!-- ======================================================================= -->
3948<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3949 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
3950</div>
3951
3952<div class="doc_text">
3953
3954<p>
3955LLVM support for <a href="GarbageCollection.html">Accurate Garbage
3956Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3957These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3958stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3959href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3960Front-ends for type-safe garbage collected languages should generate these
3961intrinsics to make use of the LLVM garbage collectors. For more details, see <a
3962href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
3963</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3964
3965<p>The garbage collection intrinsics only operate on objects in the generic
3966 address space (address space zero).</p>
3967
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3968</div>
3969
3970<!-- _______________________________________________________________________ -->
3971<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3972 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3973</div>
3974
3975<div class="doc_text">
3976
3977<h5>Syntax:</h5>
3978
3979<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]3980 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3981</pre>
3982
3983<h5>Overview:</h5>
3984
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3985<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]3986the code generator, and allows some metadata to be associated with it.</p>
3987
3988<h5>Arguments:</h5>
3989
3990<p>The first argument specifies the address of a stack object that contains the
3991root pointer. The second pointer (which must be either a constant or a global
3992value address) contains the meta-data to be associated with the root.</p>
3993
3994<h5>Semantics:</h5>
3995
3996<p>At runtime, a call to this intrinsics stores a null pointer into the "ptrloc"
3997location. At compile-time, the code generator generates information to allow
3998the runtime to find the pointer at GC safe points.
3999</p>
4000
4001</div>
4002
4003
4004<!-- _______________________________________________________________________ -->
4005<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4006 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4007</div>
4008
4009<div class="doc_text">
4010
4011<h5>Syntax:</h5>
4012
4013<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4014 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4015</pre>
4016
4017<h5>Overview:</h5>
4018
4019<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4020locations, allowing garbage collector implementations that require read
4021barriers.</p>
4022
4023<h5>Arguments:</h5>
4024
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4025<p>The second argument is the address to read from, which should be an address
4026allocated from the garbage collector. The first object is a pointer to the
4027start of the referenced object, if needed by the language runtime (otherwise
4028null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4029
4030<h5>Semantics:</h5>
4031
4032<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4033instruction, but may be replaced with substantially more complex code by the
4034garbage collector runtime, as needed.</p>
4035
4036</div>
4037
4038
4039<!-- _______________________________________________________________________ -->
4040<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4041 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4042</div>
4043
4044<div class="doc_text">
4045
4046<h5>Syntax:</h5>
4047
4048<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4049 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4050</pre>
4051
4052<h5>Overview:</h5>
4053
4054<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4055locations, allowing garbage collector implementations that require write
4056barriers (such as generational or reference counting collectors).</p>
4057
4058<h5>Arguments:</h5>
4059
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4060<p>The first argument is the reference to store, the second is the start of the
4061object to store it to, and the third is the address of the field of Obj to
4062store to. If the runtime does not require a pointer to the object, Obj may be
4063null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4064
4065<h5>Semantics:</h5>
4066
4067<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4068instruction, but may be replaced with substantially more complex code by the
4069garbage collector runtime, as needed.</p>
4070
4071</div>
4072
4073
4074
4075<!-- ======================================================================= -->
4076<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4077 <a name="int_codegen">Code Generator Intrinsics</a>
4078</div>
4079
4080<div class="doc_text">
4081<p>
4082These intrinsics are provided by LLVM to expose special features that may only
4083be implemented with code generator support.
4084</p>
4085
4086</div>
4087
4088<!-- _______________________________________________________________________ -->
4089<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4090 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4091</div>
4092
4093<div class="doc_text">
4094
4095<h5>Syntax:</h5>
4096<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4097 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4098</pre>
4099
4100<h5>Overview:</h5>
4101
4102<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4103The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4104target-specific value indicating the return address of the current function
4105or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4106</p>
4107
4108<h5>Arguments:</h5>
4109
4110<p>
4111The argument to this intrinsic indicates which function to return the address
4112for. Zero indicates the calling function, one indicates its caller, etc. The
4113argument is <b>required</b> to be a constant integer value.
4114</p>
4115
4116<h5>Semantics:</h5>
4117
4118<p>
4119The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4120the return address of the specified call frame, or zero if it cannot be
4121identified. The value returned by this intrinsic is likely to be incorrect or 0
4122for arguments other than zero, so it should only be used for debugging purposes.
4123</p>
4124
4125<p>
4126Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4127aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4128source-language caller.
4129</p>
4130</div>
4131
4132
4133<!-- _______________________________________________________________________ -->
4134<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4135 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4136</div>
4137
4138<div class="doc_text">
4139
4140<h5>Syntax:</h5>
4141<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4142 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4143</pre>
4144
4145<h5>Overview:</h5>
4146
4147<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4148The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4149target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4150</p>
4151
4152<h5>Arguments:</h5>
4153
4154<p>
4155The argument to this intrinsic indicates which function to return the frame
4156pointer for. Zero indicates the calling function, one indicates its caller,
4157etc. The argument is <b>required</b> to be a constant integer value.
4158</p>
4159
4160<h5>Semantics:</h5>
4161
4162<p>
4163The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4164the frame address of the specified call frame, or zero if it cannot be
4165identified. The value returned by this intrinsic is likely to be incorrect or 0
4166for arguments other than zero, so it should only be used for debugging purposes.
4167</p>
4168
4169<p>
4170Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4171aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4172source-language caller.
4173</p>
4174</div>
4175
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4176<!-- _______________________________________________________________________ -->
4177<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4178 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4179</div>
4180
4181<div class="doc_text">
4182
4183<h5>Syntax:</h5>
4184<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4185 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4186</pre>
4187
4188<h5>Overview:</h5>
4189
4190<p>
4191The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4192the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4193<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4194features like scoped automatic variable sized arrays in C99.
4195</p>
4196
4197<h5>Semantics:</h5>
4198
4199<p>
4200This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4201href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4202<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4203<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4204state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4205practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4206that were allocated after the <tt>llvm.stacksave</tt> was executed.
4207</p>
4208
4209</div>
4210
4211<!-- _______________________________________________________________________ -->
4212<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4213 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4214</div>
4215
4216<div class="doc_text">
4217
4218<h5>Syntax:</h5>
4219<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4220 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4221</pre>
4222
4223<h5>Overview:</h5>
4224
4225<p>
4226The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4227the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4228href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4229useful for implementing language features like scoped automatic variable sized
4230arrays in C99.
4231</p>
4232
4233<h5>Semantics:</h5>
4234
4235<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4236See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4237</p>
4238
4239</div>
4240
4241
4242<!-- _______________________________________________________________________ -->
4243<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4244 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4245</div>
4246
4247<div class="doc_text">
4248
4249<h5>Syntax:</h5>
4250<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4251 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]4252</pre>
4253
4254<h5>Overview:</h5>
4255
4256
4257<p>
4258The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4259a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4260no
4261effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]4262characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4263</p>
4264
4265<h5>Arguments:</h5>
4266
4267<p>
4268<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4269determining if the fetch should be for a read (0) or write (1), and
4270<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]4271locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4272<tt>locality</tt> arguments must be constant integers.
4273</p>
4274
4275<h5>Semantics:</h5>
4276
4277<p>
4278This intrinsic does not modify the behavior of the program. In particular,
4279prefetches cannot trap and do not produce a value. On targets that support this
4280intrinsic, the prefetch can provide hints to the processor cache for better
4281performance.
4282</p>
4283
4284</div>
4285
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4286<!-- _______________________________________________________________________ -->
4287<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4288 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4289</div>
4290
4291<div class="doc_text">
4292
4293<h5>Syntax:</h5>
4294<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4295 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4296</pre>
4297
4298<h5>Overview:</h5>
4299
4300
4301<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4302The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
4303(PC) in a region of
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4304code to simulators and other tools. The method is target specific, but it is
4305expected that the marker will use exported symbols to transmit the PC of the marker.
Jeff Cohen25d4f7e2005-11-11 02:15:27 +0000[diff] [blame]4306The marker makes no guarantees that it will remain with any specific instruction
Chris Lattnerd07c3f42005-11-15 06:07:55 +0000[diff] [blame]4307after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]4308optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4309correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4310</p>
4311
4312<h5>Arguments:</h5>
4313
4314<p>
4315<tt>id</tt> is a numerical id identifying the marker.
4316</p>
4317
4318<h5>Semantics:</h5>
4319
4320<p>
4321This intrinsic does not modify the behavior of the program. Backends that do not
4322support this intrinisic may ignore it.
4323</p>
4324
4325</div>
4326
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4327<!-- _______________________________________________________________________ -->
4328<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4329 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4330</div>
4331
4332<div class="doc_text">
4333
4334<h5>Syntax:</h5>
4335<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4336 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4337</pre>
4338
4339<h5>Overview:</h5>
4340
4341
4342<p>
4343The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4344counter register (or similar low latency, high accuracy clocks) on those targets
4345that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4346As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4347should only be used for small timings.
4348</p>
4349
4350<h5>Semantics:</h5>
4351
4352<p>
4353When directly supported, reading the cycle counter should not modify any memory.
4354Implementations are allowed to either return a application specific value or a
4355system wide value. On backends without support, this is lowered to a constant 0.
4356</p>
4357
4358</div>
4359
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4360<!-- ======================================================================= -->
4361<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4362 <a name="int_libc">Standard C Library Intrinsics</a>
4363</div>
4364
4365<div class="doc_text">
4366<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4367LLVM provides intrinsics for a few important standard C library functions.
4368These intrinsics allow source-language front-ends to pass information about the
4369alignment of the pointer arguments to the code generator, providing opportunity
4370for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4371</p>
4372
4373</div>
4374
4375<!-- _______________________________________________________________________ -->
4376<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4377 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4378</div>
4379
4380<div class="doc_text">
4381
4382<h5>Syntax:</h5>
4383<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4384 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4385 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4386 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4387 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4388</pre>
4389
4390<h5>Overview:</h5>
4391
4392<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4393The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4394location to the destination location.
4395</p>
4396
4397<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4398Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
4399intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4400</p>
4401
4402<h5>Arguments:</h5>
4403
4404<p>
4405The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4406the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4407specifying the number of bytes to copy, and the fourth argument is the alignment
4408of the source and destination locations.
4409</p>
4410
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4411<p>
4412If 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]4413the caller guarantees that both the source and destination pointers are aligned
4414to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4415</p>
4416
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4417<h5>Semantics:</h5>
4418
4419<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4420The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4421location to the destination location, which are not allowed to overlap. It
4422copies "len" bytes of memory over. If the argument is known to be aligned to
4423some boundary, this can be specified as the fourth argument, otherwise it should
4424be set to 0 or 1.
4425</p>
4426</div>
4427
4428
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4429<!-- _______________________________________________________________________ -->
4430<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4431 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4432</div>
4433
4434<div class="doc_text">
4435
4436<h5>Syntax:</h5>
4437<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4438 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4439 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4440 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4441 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4442</pre>
4443
4444<h5>Overview:</h5>
4445
4446<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4447The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
4448location to the destination location. It is similar to the
4449'<tt>llvm.memcmp</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4450</p>
4451
4452<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4453Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
4454intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4455</p>
4456
4457<h5>Arguments:</h5>
4458
4459<p>
4460The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4461the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4462specifying the number of bytes to copy, and the fourth argument is the alignment
4463of the source and destination locations.
4464</p>
4465
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4466<p>
4467If 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]4468the caller guarantees that the source and destination pointers are aligned to
4469that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4470</p>
4471
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4472<h5>Semantics:</h5>
4473
4474<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4475The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4476location to the destination location, which may overlap. It
4477copies "len" bytes of memory over. If the argument is known to be aligned to
4478some boundary, this can be specified as the fourth argument, otherwise it should
4479be set to 0 or 1.
4480</p>
4481</div>
4482
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4483
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4484<!-- _______________________________________________________________________ -->
4485<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4486 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4487</div>
4488
4489<div class="doc_text">
4490
4491<h5>Syntax:</h5>
4492<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4493 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4494 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4495 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4496 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4497</pre>
4498
4499<h5>Overview:</h5>
4500
4501<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4502The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4503byte value.
4504</p>
4505
4506<p>
4507Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
4508does not return a value, and takes an extra alignment argument.
4509</p>
4510
4511<h5>Arguments:</h5>
4512
4513<p>
4514The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4515byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4516argument specifying the number of bytes to fill, and the fourth argument is the
4517known alignment of destination location.
4518</p>
4519
4520<p>
4521If 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]4522the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4523</p>
4524
4525<h5>Semantics:</h5>
4526
4527<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4528The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
4529the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4530destination location. If the argument is known to be aligned to some boundary,
4531this can be specified as the fourth argument, otherwise it should be set to 0 or
45321.
4533</p>
4534</div>
4535
4536
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4537<!-- _______________________________________________________________________ -->
4538<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4539 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4540</div>
4541
4542<div class="doc_text">
4543
4544<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4545<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]4546floating point or vector of floating point type. Not all targets support all
4547types however.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4548<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4549 declare float @llvm.sqrt.f32(float %Val)
4550 declare double @llvm.sqrt.f64(double %Val)
4551 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
4552 declare fp128 @llvm.sqrt.f128(fp128 %Val)
4553 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4554</pre>
4555
4556<h5>Overview:</h5>
4557
4558<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4559The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4560returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4561<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
4562negative numbers (which allows for better optimization).
4563</p>
4564
4565<h5>Arguments:</h5>
4566
4567<p>
4568The argument and return value are floating point numbers of the same type.
4569</p>
4570
4571<h5>Semantics:</h5>
4572
4573<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]4574This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4575floating point number.
4576</p>
4577</div>
4578
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4579<!-- _______________________________________________________________________ -->
4580<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4581 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4582</div>
4583
4584<div class="doc_text">
4585
4586<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4587<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]4588floating point or vector of floating point type. Not all targets support all
4589types however.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4590<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4591 declare float @llvm.powi.f32(float %Val, i32 %power)
4592 declare double @llvm.powi.f64(double %Val, i32 %power)
4593 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
4594 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
4595 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4596</pre>
4597
4598<h5>Overview:</h5>
4599
4600<p>
4601The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
4602specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4603multiplications is not defined. When a vector of floating point type is
4604used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4605</p>
4606
4607<h5>Arguments:</h5>
4608
4609<p>
4610The second argument is an integer power, and the first is a value to raise to
4611that power.
4612</p>
4613
4614<h5>Semantics:</h5>
4615
4616<p>
4617This function returns the first value raised to the second power with an
4618unspecified sequence of rounding operations.</p>
4619</div>
4620
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4621<!-- _______________________________________________________________________ -->
4622<div class="doc_subsubsection">
4623 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
4624</div>
4625
4626<div class="doc_text">
4627
4628<h5>Syntax:</h5>
4629<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
4630floating point or vector of floating point type. Not all targets support all
4631types however.
4632<pre>
4633 declare float @llvm.sin.f32(float %Val)
4634 declare double @llvm.sin.f64(double %Val)
4635 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
4636 declare fp128 @llvm.sin.f128(fp128 %Val)
4637 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
4638</pre>
4639
4640<h5>Overview:</h5>
4641
4642<p>
4643The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
4644</p>
4645
4646<h5>Arguments:</h5>
4647
4648<p>
4649The argument and return value are floating point numbers of the same type.
4650</p>
4651
4652<h5>Semantics:</h5>
4653
4654<p>
4655This function returns the sine of the specified operand, returning the
4656same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4657conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4658</div>
4659
4660<!-- _______________________________________________________________________ -->
4661<div class="doc_subsubsection">
4662 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
4663</div>
4664
4665<div class="doc_text">
4666
4667<h5>Syntax:</h5>
4668<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
4669floating point or vector of floating point type. Not all targets support all
4670types however.
4671<pre>
4672 declare float @llvm.cos.f32(float %Val)
4673 declare double @llvm.cos.f64(double %Val)
4674 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
4675 declare fp128 @llvm.cos.f128(fp128 %Val)
4676 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
4677</pre>
4678
4679<h5>Overview:</h5>
4680
4681<p>
4682The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
4683</p>
4684
4685<h5>Arguments:</h5>
4686
4687<p>
4688The argument and return value are floating point numbers of the same type.
4689</p>
4690
4691<h5>Semantics:</h5>
4692
4693<p>
4694This function returns the cosine of the specified operand, returning the
4695same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4696conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4697</div>
4698
4699<!-- _______________________________________________________________________ -->
4700<div class="doc_subsubsection">
4701 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
4702</div>
4703
4704<div class="doc_text">
4705
4706<h5>Syntax:</h5>
4707<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
4708floating point or vector of floating point type. Not all targets support all
4709types however.
4710<pre>
4711 declare float @llvm.pow.f32(float %Val, float %Power)
4712 declare double @llvm.pow.f64(double %Val, double %Power)
4713 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
4714 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
4715 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
4716</pre>
4717
4718<h5>Overview:</h5>
4719
4720<p>
4721The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
4722specified (positive or negative) power.
4723</p>
4724
4725<h5>Arguments:</h5>
4726
4727<p>
4728The second argument is a floating point power, and the first is a value to
4729raise to that power.
4730</p>
4731
4732<h5>Semantics:</h5>
4733
4734<p>
4735This function returns the first value raised to the second power,
4736returning the
4737same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4738conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4739</div>
4740
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4741
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4742<!-- ======================================================================= -->
4743<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4744 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4745</div>
4746
4747<div class="doc_text">
4748<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4749LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4750These allow efficient code generation for some algorithms.
4751</p>
4752
4753</div>
4754
4755<!-- _______________________________________________________________________ -->
4756<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4757 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4758</div>
4759
4760<div class="doc_text">
4761
4762<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4763<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4764type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4765<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4766 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
4767 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
4768 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4769</pre>
4770
4771<h5>Overview:</h5>
4772
4773<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]4774The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4775values with an even number of bytes (positive multiple of 16 bits). These are
4776useful for performing operations on data that is not in the target's native
4777byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4778</p>
4779
4780<h5>Semantics:</h5>
4781
4782<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4783The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4784and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
4785intrinsic returns an i32 value that has the four bytes of the input i32
4786swapped, 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]4787i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
4788<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4789additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4790</p>
4791
4792</div>
4793
4794<!-- _______________________________________________________________________ -->
4795<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4796 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4797</div>
4798
4799<div class="doc_text">
4800
4801<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4802<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
4803width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4804<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4805 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
4806 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4807 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4808 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
4809 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4810</pre>
4811
4812<h5>Overview:</h5>
4813
4814<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]4815The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
4816value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4817</p>
4818
4819<h5>Arguments:</h5>
4820
4821<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4822The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4823integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4824</p>
4825
4826<h5>Semantics:</h5>
4827
4828<p>
4829The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
4830</p>
4831</div>
4832
4833<!-- _______________________________________________________________________ -->
4834<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4835 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4836</div>
4837
4838<div class="doc_text">
4839
4840<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4841<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
4842integer bit width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4843<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4844 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
4845 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4846 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4847 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
4848 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4849</pre>
4850
4851<h5>Overview:</h5>
4852
4853<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4854The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
4855leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4856</p>
4857
4858<h5>Arguments:</h5>
4859
4860<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4861The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4862integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4863</p>
4864
4865<h5>Semantics:</h5>
4866
4867<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4868The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
4869in 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]4870of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4871</p>
4872</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4873
4874
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4875
4876<!-- _______________________________________________________________________ -->
4877<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4878 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4879</div>
4880
4881<div class="doc_text">
4882
4883<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4884<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
4885integer bit width. Not all targets support all bit widths however.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4886<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4887 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
4888 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4889 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4890 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
4891 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4892</pre>
4893
4894<h5>Overview:</h5>
4895
4896<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4897The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
4898trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4899</p>
4900
4901<h5>Arguments:</h5>
4902
4903<p>
4904The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4905integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4906</p>
4907
4908<h5>Semantics:</h5>
4909
4910<p>
4911The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
4912in a variable. If the src == 0 then the result is the size in bits of the type
4913of src. For example, <tt>llvm.cttz(2) = 1</tt>.
4914</p>
4915</div>
4916
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]4917<!-- _______________________________________________________________________ -->
4918<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4919 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4920</div>
4921
4922<div class="doc_text">
4923
4924<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4925<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4926on any integer bit width.
4927<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4928 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
4929 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4930</pre>
4931
4932<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4933<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4934range of bits from an integer value and returns them in the same bit width as
4935the original value.</p>
4936
4937<h5>Arguments:</h5>
4938<p>The first argument, <tt>%val</tt> and the result may be integer types of
4939any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4940arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4941
4942<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4943<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4944of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
4945<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
4946operates in forward mode.</p>
4947<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
4948right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4949only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
4950<ol>
4951 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
4952 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
4953 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
4954 to determine the number of bits to retain.</li>
4955 <li>A mask of the retained bits is created by shifting a -1 value.</li>
4956 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
4957</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]4958<p>In reverse mode, a similar computation is made except that the bits are
4959returned in the reverse order. So, for example, if <tt>X</tt> has the value
4960<tt>i16 0x0ACF (101011001111)</tt> and we apply
4961<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
4962<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4963</div>
4964
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]4965<div class="doc_subsubsection">
4966 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
4967</div>
4968
4969<div class="doc_text">
4970
4971<h5>Syntax:</h5>
4972<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
4973on any integer bit width.
4974<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4975 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
4976 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]4977</pre>
4978
4979<h5>Overview:</h5>
4980<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
4981of bits in an integer value with another integer value. It returns the integer
4982with the replaced bits.</p>
4983
4984<h5>Arguments:</h5>
4985<p>The first argument, <tt>%val</tt> and the result may be integer types of
4986any bit width but they must have the same bit width. <tt>%val</tt> is the value
4987whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
4988integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
4989type since they specify only a bit index.</p>
4990
4991<h5>Semantics:</h5>
4992<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
4993of operation: forwards and reverse. If <tt>%lo</tt> is greater than
4994<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
4995operates in forward mode.</p>
4996<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
4997truncating it down to the size of the replacement area or zero extending it
4998up to that size.</p>
4999<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5000are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5001in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
5002to the <tt>%hi</tt>th bit.
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5003<p>In reverse mode, a similar computation is made except that the bits are
5004reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
5005<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]5006<h5>Examples:</h5>
5007<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5008 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5009 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5010 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5011 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5012 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5013</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5014</div>
5015
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5016<!-- ======================================================================= -->
5017<div class="doc_subsection">
5018 <a name="int_debugger">Debugger Intrinsics</a>
5019</div>
5020
5021<div class="doc_text">
5022<p>
5023The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5024are described in the <a
5025href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5026Debugging</a> document.
5027</p>
5028</div>
5029
5030
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5031<!-- ======================================================================= -->
5032<div class="doc_subsection">
5033 <a name="int_eh">Exception Handling Intrinsics</a>
5034</div>
5035
5036<div class="doc_text">
5037<p> The LLVM exception handling intrinsics (which all start with
5038<tt>llvm.eh.</tt> prefix), are described in the <a
5039href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5040Handling</a> document. </p>
5041</div>
5042
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5043<!-- ======================================================================= -->
5044<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5045 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5046</div>
5047
5048<div class="doc_text">
5049<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5050 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5051 the <tt>nest</tt> attribute, from a function. The result is a callable
5052 function pointer lacking the nest parameter - the caller does not need
5053 to provide a value for it. Instead, the value to use is stored in
5054 advance in a "trampoline", a block of memory usually allocated
5055 on the stack, which also contains code to splice the nest value into the
5056 argument list. This is used to implement the GCC nested function address
5057 extension.
5058</p>
5059<p>
5060 For example, if the function is
5061 <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]5062 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]5063<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5064 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5065 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5066 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5067 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5068</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5069 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5070 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5071</div>
5072
5073<!-- _______________________________________________________________________ -->
5074<div class="doc_subsubsection">
5075 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5076</div>
5077<div class="doc_text">
5078<h5>Syntax:</h5>
5079<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5080declare 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]5081</pre>
5082<h5>Overview:</h5>
5083<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5084 This fills the memory pointed to by <tt>tramp</tt> with code
5085 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5086</p>
5087<h5>Arguments:</h5>
5088<p>
5089 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5090 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5091 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]5092 intrinsic. Note that the size and the alignment are target-specific - LLVM
5093 currently provides no portable way of determining them, so a front-end that
5094 generates this intrinsic needs to have some target-specific knowledge.
5095 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]5096</p>
5097<h5>Semantics:</h5>
5098<p>
5099 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5100 dependent code, turning it into a function. A pointer to this function is
5101 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5102 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5103 before being called. The new function's signature is the same as that of
5104 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5105 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5106 of pointer type. Calling the new function is equivalent to calling
5107 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5108 missing <tt>nest</tt> argument. If, after calling
5109 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5110 modified, then the effect of any later call to the returned function pointer is
5111 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5112</p>
5113</div>
5114
5115<!-- ======================================================================= -->
5116<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5117 <a name="int_general">General Intrinsics</a>
5118</div>
5119
5120<div class="doc_text">
5121<p> This class of intrinsics is designed to be generic and has
5122no specific purpose. </p>
5123</div>
5124
5125<!-- _______________________________________________________________________ -->
5126<div class="doc_subsubsection">
5127 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
5128</div>
5129
5130<div class="doc_text">
5131
5132<h5>Syntax:</h5>
5133<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]5134 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]5135</pre>
5136
5137<h5>Overview:</h5>
5138
5139<p>
5140The '<tt>llvm.var.annotation</tt>' intrinsic
5141</p>
5142
5143<h5>Arguments:</h5>
5144
5145<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]5146The first argument is a pointer to a value, the second is a pointer to a
5147global string, the third is a pointer to a global string which is the source
5148file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5149</p>
5150
5151<h5>Semantics:</h5>
5152
5153<p>
5154This intrinsic allows annotation of local variables with arbitrary strings.
5155This can be useful for special purpose optimizations that want to look for these
5156 annotations. These have no other defined use, they are ignored by code
5157 generation and optimization.
5158</div>
5159
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5160<!-- _______________________________________________________________________ -->
5161<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]5162 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5163</div>
5164
5165<div class="doc_text">
5166
5167<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5168<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
5169any integer bit width.
5170</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5171<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]5172 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5173 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5174 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5175 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5176 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]5177</pre>
5178
5179<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5180
5181<p>
5182The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5183</p>
5184
5185<h5>Arguments:</h5>
5186
5187<p>
5188The first argument is an integer value (result of some expression),
5189the second is a pointer to a global string, the third is a pointer to a global
5190string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5191It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5192</p>
5193
5194<h5>Semantics:</h5>
5195
5196<p>
5197This intrinsic allows annotations to be put on arbitrary expressions
5198with arbitrary strings. This can be useful for special purpose optimizations
5199that want to look for these annotations. These have no other defined use, they
5200are ignored by code generation and optimization.
5201</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5202
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5203<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5204<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]5205<address>
5206 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
5207 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
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5209 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
5210
5211 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]5212 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]5213 Last modified: $Date$
5214</address>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5215</body>
5216</html>