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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / b9488a68906811f3fc93383fe7866c9640051615 / . / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
8 <meta name="description"
9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
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">
1111 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1112 <tt>[40 x i32 ]</tt><br/>
1113 <tt>[41 x i32 ]</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1114 <tt>[40 x i8]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1115 </td>
1116 <td class="left">
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1117 Array of 40 32-bit integer values.<br/>
1118 Array of 41 32-bit integer values.<br/>
1119 Array of 40 8-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1120 </td>
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">
1126 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1127 <tt>[3 x [4 x i32]]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1128 <tt>[12 x [10 x float]]</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1129 <tt>[2 x [3 x [4 x i16]]]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1130 </td>
1131 <td class="left">
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1132 3x4 array of 32-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1133 12x10 array of single precision floating point values.<br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1134 2x3x4 array of 16-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1135 </td>
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">
1242 <td class="left"><tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}&nbsp;&gt;</tt></td>
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">
1265 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1266 <tt>[4x i32]*</tt><br/>
1267 <tt>i32 (i32 *) *</tt><br/>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1268 <tt>i32 addrspace(5)*</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1269 </td>
1270 <td class="left">
1271 A <a href="#t_pointer">pointer</a> to <a href="#t_array">array</a> of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1272 four <tt>i32</tt> values<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1273 A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1274 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
1275 <tt>i32</tt>.<br/>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]1276 A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value that resides
1277 in address space 5.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1278 </td>
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">
1310 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1311 <tt>&lt;4 x i32&gt;</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1312 <tt>&lt;8 x float&gt;</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1313 <tt>&lt;2 x i64&gt;</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1314 </td>
1315 <td class="left">
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1316 Vector of 4 32-bit integer values.<br/>
1317 Vector of 8 floating-point values.<br/>
1318 Vector of 2 64-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1319 </td>
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">
1345 <td class="left">
1346 <tt>opaque</tt>
1347 </td>
1348 <td class="left">
1349 An opaque type.<br/>
1350 </td>
1351 </tr>
1352</table>
1353</div>
1354
1355
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1356<!-- *********************************************************************** -->
1357<div class="doc_section"> <a name="constants">Constants</a> </div>
1358<!-- *********************************************************************** -->
1359
1360<div class="doc_text">
1361
1362<p>LLVM has several different basic types of constants. This section describes
1363them all and their syntax.</p>
1364
1365</div>
1366
1367<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1368<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1369
1370<div class="doc_text">
1371
1372<dl>
1373 <dt><b>Boolean constants</b></dt>
1374
1375 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1376 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1377 </dd>
1378
1379 <dt><b>Integer constants</b></dt>
1380
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1381 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1382 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1383 integer types.
1384 </dd>
1385
1386 <dt><b>Floating point constants</b></dt>
1387
1388 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1389 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1390 notation (see below). Floating point constants must have a <a
1391 href="#t_floating">floating point</a> type. </dd>
1392
1393 <dt><b>Null pointer constants</b></dt>
1394
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1395 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1396 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1397
1398</dl>
1399
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1400<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1401of floating point constants. For example, the form '<tt>double
14020x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
14034.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1404(and the only time that they are generated by the disassembler) is when a
1405floating point constant must be emitted but it cannot be represented as a
1406decimal floating point number. For example, NaN's, infinities, and other
1407special values are represented in their IEEE hexadecimal format so that
1408assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1409
1410</div>
1411
1412<!-- ======================================================================= -->
1413<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1414</div>
1415
1416<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1417<p>Aggregate constants arise from aggregation of simple constants
1418and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1419
1420<dl>
1421 <dt><b>Structure constants</b></dt>
1422
1423 <dd>Structure constants are represented with notation similar to structure
1424 type definitions (a comma separated list of elements, surrounded by braces
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1425 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* %G }</tt>",
Chris Lattner3e63a9d2007-07-13 20:01:46 +0000[diff] [blame]1426 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]1427 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1428 types of elements must match those specified by the type.
1429 </dd>
1430
1431 <dt><b>Array constants</b></dt>
1432
1433 <dd>Array constants are represented with notation similar to array type
1434 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1435 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1436 constants must have <a href="#t_array">array type</a>, and the number and
1437 types of elements must match those specified by the type.
1438 </dd>
1439
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1440 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1441
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1442 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1443 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1444 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]1445 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1446 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1447 match those specified by the type.
1448 </dd>
1449
1450 <dt><b>Zero initialization</b></dt>
1451
1452 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1453 value to zero of <em>any</em> type, including scalar and aggregate types.
1454 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]1455 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1456 initializers.
1457 </dd>
1458</dl>
1459
1460</div>
1461
1462<!-- ======================================================================= -->
1463<div class="doc_subsection">
1464 <a name="globalconstants">Global Variable and Function Addresses</a>
1465</div>
1466
1467<div class="doc_text">
1468
1469<p>The addresses of <a href="#globalvars">global variables</a> and <a
1470href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1471constants. These constants are explicitly referenced when the <a
1472href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1473href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1474file:</p>
1475
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1476<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1477<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1478@X = global i32 17
1479@Y = global i32 42
1480@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1481</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1482</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1483
1484</div>
1485
1486<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1487<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1488<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1489 <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]1490 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1491 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1492
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1493 <p>Undefined values indicate to the compiler that the program is well defined
1494 no matter what value is used, giving the compiler more freedom to optimize.
1495 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1496</div>
1497
1498<!-- ======================================================================= -->
1499<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1500</div>
1501
1502<div class="doc_text">
1503
1504<p>Constant expressions are used to allow expressions involving other constants
1505to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1506href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1507that does not have side effects (e.g. load and call are not supported). The
1508following is the syntax for constant expressions:</p>
1509
1510<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1511 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1512 <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]1513 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1514
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1515 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1516 <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]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>sext ( CST to TYPE )</tt></b></dt>
1520 <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]1521 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]1522
1523 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1524 <dd>Truncate a floating point constant to another floating point type. The
1525 size of CST must be larger than the size of TYPE. Both types must be
1526 floating point.</dd>
1527
1528 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1529 <dd>Floating point extend a constant to another type. The size of CST must be
1530 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1531
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1532 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1533 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1534 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1535 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1536 of the same number of elements. If the value won't fit in the integer type,
1537 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1538
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1539 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1540 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1541 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1542 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1543 of the same number of elements. If the value won't fit in the integer type,
1544 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1545
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1546 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1547 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1548 constant. TYPE must be a scalar or vector floating point type. CST must be of
1549 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1550 of the same number of elements. If the value won't fit in the floating point
1551 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1552
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1553 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1554 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1555 constant. TYPE must be a scalar or vector floating point type. CST must be of
1556 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1557 of the same number of elements. If the value won't fit in the floating point
1558 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1559
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1560 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1561 <dd>Convert a pointer typed constant to the corresponding integer constant
1562 TYPE must be an integer type. CST must be of pointer type. The CST value is
1563 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1564
1565 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1566 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1567 pointer type. CST must be of integer type. The CST value is zero extended,
1568 truncated, or unchanged to make it fit in a pointer size. This one is
1569 <i>really</i> dangerous!</dd>
1570
1571 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1572 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1573 identical (same number of bits). The conversion is done as if the CST value
1574 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]1575 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1576 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]1577 pointers it is only valid to cast to another pointer type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1578 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1579
1580 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1581
1582 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1583 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1584 instruction, the index list may have zero or more indexes, which are required
1585 to make sense for the type of "CSTPTR".</dd>
1586
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1587 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1588
1589 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1590 constants.</dd>
1591
1592 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1593 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1594
1595 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1596 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1597
1598 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1599
1600 <dd>Perform the <a href="#i_extractelement">extractelement
1601 operation</a> on constants.
1602
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1603 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1604
1605 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1606 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1607
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1608
1609 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1610
1611 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1612 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1613
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1614 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1615
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1616 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1617 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1618 binary</a> operations. The constraints on operands are the same as those for
1619 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1620 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1621</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1622</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1623
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1624<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1625<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1626<!-- *********************************************************************** -->
1627
1628<!-- ======================================================================= -->
1629<div class="doc_subsection">
1630<a name="inlineasm">Inline Assembler Expressions</a>
1631</div>
1632
1633<div class="doc_text">
1634
1635<p>
1636LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1637Module-Level Inline Assembly</a>) through the use of a special value. This
1638value represents the inline assembler as a string (containing the instructions
1639to emit), a list of operand constraints (stored as a string), and a flag that
1640indicates whether or not the inline asm expression has side effects. An example
1641inline assembler expression is:
1642</p>
1643
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1644<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1645<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1646i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1647</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1648</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1649
1650<p>
1651Inline assembler expressions may <b>only</b> be used as the callee operand of
1652a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1653</p>
1654
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1655<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1656<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1657%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]1658</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1659</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1660
1661<p>
1662Inline asms with side effects not visible in the constraint list must be marked
1663as having side effects. This is done through the use of the
1664'<tt>sideeffect</tt>' keyword, like so:
1665</p>
1666
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1667<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1668<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1669call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1670</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1671</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1672
1673<p>TODO: The format of the asm and constraints string still need to be
1674documented here. Constraints on what can be done (e.g. duplication, moving, etc
1675need to be documented).
1676</p>
1677
1678</div>
1679
1680<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1681<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1682<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1683
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1684<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1685
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1686<p>The LLVM instruction set consists of several different
1687classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1688instructions</a>, <a href="#binaryops">binary instructions</a>,
1689<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1690 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1691instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1692
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1693</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1694
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1695<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1696<div class="doc_subsection"> <a name="terminators">Terminator
1697Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1698
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1699<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1700
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1701<p>As mentioned <a href="#functionstructure">previously</a>, every
1702basic block in a program ends with a "Terminator" instruction, which
1703indicates which block should be executed after the current block is
1704finished. These terminator instructions typically yield a '<tt>void</tt>'
1705value: they produce control flow, not values (the one exception being
1706the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1707<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1708 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1709instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1710the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1711 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1712 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1713
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1714</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1715
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1716<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1717<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1718Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1719<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1720<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1721<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]1722 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1723</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1724<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1725<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1726value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]1727<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1728returns a value and then causes control flow, and one that just causes
1729control flow to occur.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1730<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1731<p>The '<tt>ret</tt>' instruction may return any '<a
1732 href="#t_firstclass">first class</a>' type. Notice that a function is
1733not <a href="#wellformed">well formed</a> if there exists a '<tt>ret</tt>'
1734instruction inside of the function that returns a value that does not
1735match the return type of the function.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1736<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1737<p>When the '<tt>ret</tt>' instruction is executed, control flow
1738returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]1739 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1740the instruction after the call. If the caller was an "<a
1741 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1742at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1743returns a value, that value shall set the call or invoke instruction's
1744return value.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1745<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1746<pre> ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1747 ret void <i>; Return from a void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1748</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1749</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1750<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1751<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1752<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1753<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1754<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]1755</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1756<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1757<p>The '<tt>br</tt>' instruction is used to cause control flow to
1758transfer to a different basic block in the current function. There are
1759two forms of this instruction, corresponding to a conditional branch
1760and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1761<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1762<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1763single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1764unconditional form of the '<tt>br</tt>' instruction takes a single
1765'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1766<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1767<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1768argument is evaluated. If the value is <tt>true</tt>, control flows
1769to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1770control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1771<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1772<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]1773 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]1774</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1775<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1776<div class="doc_subsubsection">
1777 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1778</div>
1779
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1780<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1781<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1782
1783<pre>
1784 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1785</pre>
1786
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1787<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1788
1789<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1790several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1791instruction, allowing a branch to occur to one of many possible
1792destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1793
1794
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1795<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1796
1797<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1798comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1799an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1800table is not allowed to contain duplicate constant entries.</p>
1801
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1802<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1803
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1804<p>The <tt>switch</tt> instruction specifies a table of values and
1805destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1806table is searched for the given value. If the value is found, control flow is
1807transfered to the corresponding destination; otherwise, control flow is
1808transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1809
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1810<h5>Implementation:</h5>
1811
1812<p>Depending on properties of the target machine and the particular
1813<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1814ways. For example, it could be generated as a series of chained conditional
1815branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1816
1817<h5>Example:</h5>
1818
1819<pre>
1820 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1821 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1822 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1823
1824 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1825 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1826
1827 <i>; Implement a jump table:</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1828 switch i32 %val, label %otherwise [ i32 0, label %onzero
1829 i32 1, label %onone
1830 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1831</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1832</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1833
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1834<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1835<div class="doc_subsubsection">
1836 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
1837</div>
1838
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1839<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1840
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1841<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1842
1843<pre>
1844 &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]1845 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1846</pre>
1847
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]1848<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1849
1850<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
1851function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1852'<tt>normal</tt>' label or the
1853'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1854"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
1855"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1856href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
1857continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1858
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1859<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1860
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1861<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1862
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1863<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1864 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]1865 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1866 convention</a> the call should use. If none is specified, the call defaults
1867 to using C calling conventions.
1868 </li>
1869 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
1870 function value being invoked. In most cases, this is a direct function
1871 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
1872 an arbitrary pointer to function value.
1873 </li>
1874
1875 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
1876 function to be invoked. </li>
1877
1878 <li>'<tt>function args</tt>': argument list whose types match the function
1879 signature argument types. If the function signature indicates the function
1880 accepts a variable number of arguments, the extra arguments can be
1881 specified. </li>
1882
1883 <li>'<tt>normal label</tt>': the label reached when the called function
1884 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
1885
1886 <li>'<tt>exception label</tt>': the label reached when a callee returns with
1887 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
1888
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1889</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1890
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1891<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1892
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1893<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1894href="#i_call">call</a></tt>' instruction in most regards. The primary
1895difference is that it establishes an association with a label, which is used by
1896the runtime library to unwind the stack.</p>
1897
1898<p>This instruction is used in languages with destructors to ensure that proper
1899cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
1900exception. Additionally, this is important for implementation of
1901'<tt>catch</tt>' clauses in high-level languages that support them.</p>
1902
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1903<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1904<pre>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1905 %retval = invoke i32 %Test(i32 15) to label %Continue
1906 unwind label %TestCleanup <i>; {i32}:retval set</i>
1907 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Test(i32 15) to label %Continue
1908 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1909</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1910</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1911
1912
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1913<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1914
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1915<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
1916Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1917
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1918<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1919
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1920<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1921<pre>
1922 unwind
1923</pre>
1924
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1925<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1926
1927<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
1928at the first callee in the dynamic call stack which used an <a
1929href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
1930primarily used to implement exception handling.</p>
1931
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1932<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1933
1934<p>The '<tt>unwind</tt>' intrinsic causes execution of the current function to
1935immediately halt. The dynamic call stack is then searched for the first <a
1936href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
1937execution continues at the "exceptional" destination block specified by the
1938<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
1939dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1940</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1941
1942<!-- _______________________________________________________________________ -->
1943
1944<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
1945Instruction</a> </div>
1946
1947<div class="doc_text">
1948
1949<h5>Syntax:</h5>
1950<pre>
1951 unreachable
1952</pre>
1953
1954<h5>Overview:</h5>
1955
1956<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
1957instruction is used to inform the optimizer that a particular portion of the
1958code is not reachable. This can be used to indicate that the code after a
1959no-return function cannot be reached, and other facts.</p>
1960
1961<h5>Semantics:</h5>
1962
1963<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
1964</div>
1965
1966
1967
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1968<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1969<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1970<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1971<p>Binary operators are used to do most of the computation in a
1972program. They require two operands, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1973produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1974multiple 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]1975The result value of a binary operator is not
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1976necessarily the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1977<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1978</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1979<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1980<div class="doc_subsubsection"> <a name="i_add">'<tt>add</tt>'
1981Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1982<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1983<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1984<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]1985</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1986<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1987<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1988<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1989<p>The two arguments to the '<tt>add</tt>' instruction must be either <a
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1990 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a> values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1991 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]1992Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1993<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1994<p>The value produced is the integer or floating point sum of the two
1995operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1996<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1997<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]1998</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1999</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2000<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2001<div class="doc_subsubsection"> <a name="i_sub">'<tt>sub</tt>'
2002Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2003<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2004<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2005<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]2006</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2007<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2008<p>The '<tt>sub</tt>' instruction returns the difference of its two
2009operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2010<p>Note that the '<tt>sub</tt>' instruction is used to represent the '<tt>neg</tt>'
2011instruction present in most other intermediate representations.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2012<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2013<p>The two arguments to the '<tt>sub</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2014 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2015values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2016This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2017Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2018<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2019<p>The value produced is the integer or floating point difference of
2020the two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2021<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2022<pre>
2023 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2024 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2025</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2026</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2027<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2028<div class="doc_subsubsection"> <a name="i_mul">'<tt>mul</tt>'
2029Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2030<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2031<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2032<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]2033</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2034<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2035<p>The '<tt>mul</tt>' instruction returns the product of its two
2036operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2037<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2038<p>The two arguments to the '<tt>mul</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2039 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2040values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2041This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2042Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2043<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2044<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2045two operands.</p>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]2046<p>Because the operands are the same width, the result of an integer
2047multiplication is the same whether the operands should be deemed unsigned or
2048signed.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2049<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2050<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]2051</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2052</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2053<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2054<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2055</a></div>
2056<div class="doc_text">
2057<h5>Syntax:</h5>
2058<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2059</pre>
2060<h5>Overview:</h5>
2061<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2062operands.</p>
2063<h5>Arguments:</h5>
2064<p>The two arguments to the '<tt>udiv</tt>' instruction must be
2065<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2066types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2067of the values in which case the elements must be integers.</p>
2068<h5>Semantics:</h5>
2069<p>The value produced is the unsigned integer quotient of the two operands. This
2070instruction always performs an unsigned division operation, regardless of
2071whether the arguments are unsigned or not.</p>
2072<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2073<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]2074</pre>
2075</div>
2076<!-- _______________________________________________________________________ -->
2077<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2078</a> </div>
2079<div class="doc_text">
2080<h5>Syntax:</h5>
2081<pre> &lt;result&gt; = sdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2082</pre>
2083<h5>Overview:</h5>
2084<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2085operands.</p>
2086<h5>Arguments:</h5>
2087<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2088<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2089types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2090of the values in which case the elements must be integers.</p>
2091<h5>Semantics:</h5>
2092<p>The value produced is the signed integer quotient of the two operands. This
2093instruction always performs a signed division operation, regardless of whether
2094the arguments are signed or not.</p>
2095<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2096<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]2097</pre>
2098</div>
2099<!-- _______________________________________________________________________ -->
2100<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2101Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2102<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2103<h5>Syntax:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2104<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]2105</pre>
2106<h5>Overview:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2107<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2108operands.</p>
2109<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2110<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2111<a href="#t_floating">floating point</a> values. Both arguments must have
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2112identical types. This instruction can also take <a href="#t_vector">vector</a>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2113versions of floating point values.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2114<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2115<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2116<h5>Example:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2117<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]2118</pre>
2119</div>
2120<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2121<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2122</div>
2123<div class="doc_text">
2124<h5>Syntax:</h5>
2125<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2126</pre>
2127<h5>Overview:</h5>
2128<p>The '<tt>urem</tt>' instruction returns the remainder from the
2129unsigned division of its two arguments.</p>
2130<h5>Arguments:</h5>
2131<p>The two arguments to the '<tt>urem</tt>' instruction must be
2132<a href="#t_integer">integer</a> values. Both arguments must have identical
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2133types. This instruction can also take <a href="#t_vector">vector</a> versions
2134of the values in which case the elements must be integers.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2135<h5>Semantics:</h5>
2136<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
2137This instruction always performs an unsigned division to get the remainder,
2138regardless of whether the arguments are unsigned or not.</p>
2139<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2140<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]2141</pre>
2142
2143</div>
2144<!-- _______________________________________________________________________ -->
2145<div class="doc_subsubsection"> <a name="i_srem">'<tt>srem</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2146Instruction</a> </div>
2147<div class="doc_text">
2148<h5>Syntax:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2149<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]2150</pre>
2151<h5>Overview:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2152<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2153signed division of its two operands. This instruction can also take
2154<a href="#t_vector">vector</a> versions of the values in which case
2155the elements must be integers.</p>
2156</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2157<h5>Arguments:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2158<p>The two arguments to the '<tt>srem</tt>' instruction must be
2159<a href="#t_integer">integer</a> values. Both arguments must have identical
2160types.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2161<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2162<p>This instruction returns the <i>remainder</i> of a division (where the result
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2163has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
2164operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
2165a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2166 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2167Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2168please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2169Wikipedia: modulo operation</a>.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2170<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2171<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]2172</pre>
2173
2174</div>
2175<!-- _______________________________________________________________________ -->
2176<div class="doc_subsubsection"> <a name="i_frem">'<tt>frem</tt>'
2177Instruction</a> </div>
2178<div class="doc_text">
2179<h5>Syntax:</h5>
2180<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2181</pre>
2182<h5>Overview:</h5>
2183<p>The '<tt>frem</tt>' instruction returns the remainder from the
2184division of its two operands.</p>
2185<h5>Arguments:</h5>
2186<p>The two arguments to the '<tt>frem</tt>' instruction must be
2187<a href="#t_floating">floating point</a> values. Both arguments must have
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2188identical types. This instruction can also take <a href="#t_vector">vector</a>
2189versions of floating point values.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2190<h5>Semantics:</h5>
2191<p>This instruction returns the <i>remainder</i> of a division.</p>
2192<h5>Example:</h5>
2193<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]2194</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2195</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2196
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2197<!-- ======================================================================= -->
2198<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2199Operations</a> </div>
2200<div class="doc_text">
2201<p>Bitwise binary operators are used to do various forms of
2202bit-twiddling in a program. They are generally very efficient
2203instructions and can commonly be strength reduced from other
2204instructions. They require two operands, execute an operation on them,
2205and produce a single value. The resulting value of the bitwise binary
2206operators is always the same type as its first operand.</p>
2207</div>
2208
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2209<!-- _______________________________________________________________________ -->
2210<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2211Instruction</a> </div>
2212<div class="doc_text">
2213<h5>Syntax:</h5>
2214<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2215</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2216
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2217<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2218
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2219<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2220the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2221
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2222<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2223
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2224<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
2225 href="#t_integer">integer</a> type.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2226
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2227<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2228
2229<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup>. If
2230<tt>var2</tt> is (statically or dynamically) equal to or larger than the number
2231of bits in <tt>var1</tt>, the result is undefined.</p>
2232
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2233<h5>Example:</h5><pre>
2234 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2235 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2236 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2237 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2238</pre>
2239</div>
2240<!-- _______________________________________________________________________ -->
2241<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2242Instruction</a> </div>
2243<div class="doc_text">
2244<h5>Syntax:</h5>
2245<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2246</pre>
2247
2248<h5>Overview:</h5>
2249<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2250operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2251
2252<h5>Arguments:</h5>
2253<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
2254<a href="#t_integer">integer</a> type.</p>
2255
2256<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2257
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2258<p>This instruction always performs a logical shift right operation. The most
2259significant bits of the result will be filled with zero bits after the
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2260shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
2261the number of bits in <tt>var1</tt>, the result is undefined.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2262
2263<h5>Example:</h5>
2264<pre>
2265 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2266 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2267 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2268 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2269 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2270</pre>
2271</div>
2272
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2273<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2274<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2275Instruction</a> </div>
2276<div class="doc_text">
2277
2278<h5>Syntax:</h5>
2279<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2280</pre>
2281
2282<h5>Overview:</h5>
2283<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2284operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2285
2286<h5>Arguments:</h5>
2287<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
2288<a href="#t_integer">integer</a> type.</p>
2289
2290<h5>Semantics:</h5>
2291<p>This instruction always performs an arithmetic shift right operation,
2292The most significant bits of the result will be filled with the sign bit
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2293of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
2294larger than the number of bits in <tt>var1</tt>, the result is undefined.
2295</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2296
2297<h5>Example:</h5>
2298<pre>
2299 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2300 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2301 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2302 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2303 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2304</pre>
2305</div>
2306
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2307<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2308<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2309Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2310<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2311<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2312<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]2313</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2314<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2315<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2316its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2317<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2318<p>The two arguments to the '<tt>and</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2319 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2320identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2321<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2322<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2323<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2324<div style="align: center">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2325<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2326 <tbody>
2327 <tr>
2328 <td>In0</td>
2329 <td>In1</td>
2330 <td>Out</td>
2331 </tr>
2332 <tr>
2333 <td>0</td>
2334 <td>0</td>
2335 <td>0</td>
2336 </tr>
2337 <tr>
2338 <td>0</td>
2339 <td>1</td>
2340 <td>0</td>
2341 </tr>
2342 <tr>
2343 <td>1</td>
2344 <td>0</td>
2345 <td>0</td>
2346 </tr>
2347 <tr>
2348 <td>1</td>
2349 <td>1</td>
2350 <td>1</td>
2351 </tr>
2352 </tbody>
2353</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2354</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2355<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2356<pre> &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
2357 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2358 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2359</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2360</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2361<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2362<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2363<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2364<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2365<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]2366</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2367<h5>Overview:</h5>
2368<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2369or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2370<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2371<p>The two arguments to the '<tt>or</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2372 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2373identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2374<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2375<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2376<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2377<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2378<table border="1" cellspacing="0" cellpadding="4">
2379 <tbody>
2380 <tr>
2381 <td>In0</td>
2382 <td>In1</td>
2383 <td>Out</td>
2384 </tr>
2385 <tr>
2386 <td>0</td>
2387 <td>0</td>
2388 <td>0</td>
2389 </tr>
2390 <tr>
2391 <td>0</td>
2392 <td>1</td>
2393 <td>1</td>
2394 </tr>
2395 <tr>
2396 <td>1</td>
2397 <td>0</td>
2398 <td>1</td>
2399 </tr>
2400 <tr>
2401 <td>1</td>
2402 <td>1</td>
2403 <td>1</td>
2404 </tr>
2405 </tbody>
2406</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2407</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2408<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2409<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2410 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2411 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2412</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2413</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2414<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2415<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2416Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2417<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2418<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2419<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]2420</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2421<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2422<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2423or of its two operands. The <tt>xor</tt> is used to implement the
2424"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2425<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2426<p>The two arguments to the '<tt>xor</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2427 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2428identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2429<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2430<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2431<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2432<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2433<table border="1" cellspacing="0" cellpadding="4">
2434 <tbody>
2435 <tr>
2436 <td>In0</td>
2437 <td>In1</td>
2438 <td>Out</td>
2439 </tr>
2440 <tr>
2441 <td>0</td>
2442 <td>0</td>
2443 <td>0</td>
2444 </tr>
2445 <tr>
2446 <td>0</td>
2447 <td>1</td>
2448 <td>1</td>
2449 </tr>
2450 <tr>
2451 <td>1</td>
2452 <td>0</td>
2453 <td>1</td>
2454 </tr>
2455 <tr>
2456 <td>1</td>
2457 <td>1</td>
2458 <td>0</td>
2459 </tr>
2460 </tbody>
2461</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2462</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2463<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2464<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2465<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2466 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2467 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2468 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2469</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2470</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2471
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2472<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2473<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2474 <a name="vectorops">Vector Operations</a>
2475</div>
2476
2477<div class="doc_text">
2478
2479<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2480target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2481vector-specific operations needed to process vectors effectively. While LLVM
2482does directly support these vector operations, many sophisticated algorithms
2483will want to use target-specific intrinsics to take full advantage of a specific
2484target.</p>
2485
2486</div>
2487
2488<!-- _______________________________________________________________________ -->
2489<div class="doc_subsubsection">
2490 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2491</div>
2492
2493<div class="doc_text">
2494
2495<h5>Syntax:</h5>
2496
2497<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2498 &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]2499</pre>
2500
2501<h5>Overview:</h5>
2502
2503<p>
2504The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2505element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2506</p>
2507
2508
2509<h5>Arguments:</h5>
2510
2511<p>
2512The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2513value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2514an index indicating the position from which to extract the element.
2515The index may be a variable.</p>
2516
2517<h5>Semantics:</h5>
2518
2519<p>
2520The result is a scalar of the same type as the element type of
2521<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2522<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2523results are undefined.
2524</p>
2525
2526<h5>Example:</h5>
2527
2528<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2529 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2530</pre>
2531</div>
2532
2533
2534<!-- _______________________________________________________________________ -->
2535<div class="doc_subsubsection">
2536 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2537</div>
2538
2539<div class="doc_text">
2540
2541<h5>Syntax:</h5>
2542
2543<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2544 &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]2545</pre>
2546
2547<h5>Overview:</h5>
2548
2549<p>
2550The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2551element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2552</p>
2553
2554
2555<h5>Arguments:</h5>
2556
2557<p>
2558The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2559value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2560scalar value whose type must equal the element type of the first
2561operand. The third operand is an index indicating the position at
2562which to insert the value. The index may be a variable.</p>
2563
2564<h5>Semantics:</h5>
2565
2566<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2567The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2568element values are those of <tt>val</tt> except at position
2569<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2570exceeds the length of <tt>val</tt>, the results are undefined.
2571</p>
2572
2573<h5>Example:</h5>
2574
2575<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2576 %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]2577</pre>
2578</div>
2579
2580<!-- _______________________________________________________________________ -->
2581<div class="doc_subsubsection">
2582 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2583</div>
2584
2585<div class="doc_text">
2586
2587<h5>Syntax:</h5>
2588
2589<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2590 &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]2591</pre>
2592
2593<h5>Overview:</h5>
2594
2595<p>
2596The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2597from two input vectors, returning a vector of the same type.
2598</p>
2599
2600<h5>Arguments:</h5>
2601
2602<p>
2603The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2604with types that match each other and types that match the result of the
2605instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2606of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2607</p>
2608
2609<p>
2610The shuffle mask operand is required to be a constant vector with either
2611constant integer or undef values.
2612</p>
2613
2614<h5>Semantics:</h5>
2615
2616<p>
2617The elements of the two input vectors are numbered from left to right across
2618both of the vectors. The shuffle mask operand specifies, for each element of
2619the result vector, which element of the two input registers the result element
2620gets. The element selector may be undef (meaning "don't care") and the second
2621operand may be undef if performing a shuffle from only one vector.
2622</p>
2623
2624<h5>Example:</h5>
2625
2626<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2627 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2628 &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]2629 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2630 &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]2631</pre>
2632</div>
2633
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]2634
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2635<!-- ======================================================================= -->
2636<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2637 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2638</div>
2639
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2640<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2641
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2642<p>A key design point of an SSA-based representation is how it
2643represents memory. In LLVM, no memory locations are in SSA form, which
2644makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2645allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2646
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2647</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2648
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2649<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2650<div class="doc_subsubsection">
2651 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
2652</div>
2653
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2654<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2655
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2656<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2657
2658<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2659 &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]2660</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2661
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2662<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2663
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2664<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]2665heap and returns a pointer to it. The object is always allocated in the generic
2666address space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2667
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2668<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2669
2670<p>The '<tt>malloc</tt>' instruction allocates
2671<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]2672bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2673appropriate type to the program. If "NumElements" is specified, it is the
2674number of elements allocated. If an alignment is specified, the value result
2675of the allocation is guaranteed to be aligned to at least that boundary. If
2676not specified, or if zero, the target can choose to align the allocation on any
2677convenient boundary.</p>
2678
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2679<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2680
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2681<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2682
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2683<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
2684a pointer is returned.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2685
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2686<h5>Example:</h5>
2687
2688<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2689 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2690
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2691 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
2692 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
2693 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
2694 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
2695 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2696</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2697</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2698
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2699<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2700<div class="doc_subsubsection">
2701 <a name="i_free">'<tt>free</tt>' Instruction</a>
2702</div>
2703
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2704<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2705
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2706<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2707
2708<pre>
2709 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2710</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2711
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2712<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2713
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2714<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2715memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2716
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2717<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2718
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2719<p>'<tt>value</tt>' shall be a pointer value that points to a value
2720that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
2721instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2722
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2723<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2724
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2725<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2726after this instruction executes.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2727
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2728<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2729
2730<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2731 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
2732 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2733</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2734</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2735
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2736<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2737<div class="doc_subsubsection">
2738 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
2739</div>
2740
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2741<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2742
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2743<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2744
2745<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2746 &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]2747</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2748
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2749<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2750
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2751<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
2752currently executing function, to be automatically released when this function
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]2753returns to its caller. The object is always allocated in the generic address
2754space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2755
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2756<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2757
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2758<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2759bytes of memory on the runtime stack, returning a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2760appropriate type to the program. If "NumElements" is specified, it is the
2761number of elements allocated. If an alignment is specified, the value result
2762of the allocation is guaranteed to be aligned to at least that boundary. If
2763not specified, or if zero, the target can choose to align the allocation on any
2764convenient boundary.</p>
2765
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2766<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2767
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2768<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2769
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2770<p>Memory is allocated; a pointer is returned. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2771memory is automatically released when the function returns. The '<tt>alloca</tt>'
2772instruction is commonly used to represent automatic variables that must
2773have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]2774 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]2775instructions), the memory is reclaimed.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2776
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2777<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2778
2779<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2780 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2781 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
2782 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2783 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2784</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2785</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2786
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2787<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2788<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
2789Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2790<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2791<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2792<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]2793<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2794<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2795<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2796<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2797address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]2798 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2799marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2800the number or order of execution of this <tt>load</tt> with other
2801volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
2802instructions. </p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2803<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2804<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2805<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2806<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2807 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2808 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
2809 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2810</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2811</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2812<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2813<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
2814Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]2815<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2816<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2817<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
2818 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]2819</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2820<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2821<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2822<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2823<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2824to 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]2825operand must be a pointer to the type of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2826operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2827optimizer is not allowed to modify the number or order of execution of
2828this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
2829 href="#i_store">store</a></tt> instructions.</p>
2830<h5>Semantics:</h5>
2831<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
2832at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2833<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2834<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]2835 store i32 3, i32* %ptr <i>; yields {void}</i>
2836 %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]2837</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2838</div>
2839
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2840<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2841<div class="doc_subsubsection">
2842 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
2843</div>
2844
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2845<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2846<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2847<pre>
2848 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
2849</pre>
2850
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2851<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2852
2853<p>
2854The '<tt>getelementptr</tt>' instruction is used to get the address of a
2855subelement of an aggregate data structure.</p>
2856
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2857<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2858
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2859<p>This instruction takes a list of integer operands that indicate what
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2860elements of the aggregate object to index to. The actual types of the arguments
2861provided depend on the type of the first pointer argument. The
2862'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]2863levels 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]2864structure, only <tt>i32</tt> integer constants are allowed. When indexing
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2865into an array or pointer, only integers of 32 or 64 bits are allowed, and will
2866be sign extended to 64-bit values.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2867
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2868<p>For example, let's consider a C code fragment and how it gets
2869compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2870
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2871<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2872<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2873struct RT {
2874 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2875 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2876 char C;
2877};
2878struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2879 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2880 double Y;
2881 struct RT Z;
2882};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2883
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2884int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2885 return &amp;s[1].Z.B[5][13];
2886}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2887</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2888</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2889
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2890<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2891
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2892<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2893<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2894%RT = type { i8 , [10 x [20 x i32]], i8 }
2895%ST = type { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2896
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2897define i32* %foo(%ST* %s) {
2898entry:
2899 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
2900 ret i32* %reg
2901}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2902</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2903</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2904
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2905<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2906
2907<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2908on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2909and <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]2910<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]2911to 64-bits. <a href="#t_struct">Structure</a> types require <tt>i32</tt>
Reid Spencer42ddd842006-12-03 16:53:48 +0000[diff] [blame]2912<b>constants</b>.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2913
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2914<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]2915type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2916}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2917the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
2918i8 }</tt>' type, another structure. The third index indexes into the second
2919element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2920array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2921'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
2922to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2923
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2924<p>Note that it is perfectly legal to index partially through a
2925structure, returning a pointer to an inner element. Because of this,
2926the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2927
2928<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2929 define i32* %foo(%ST* %s) {
2930 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2931 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
2932 %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]2933 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
2934 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
2935 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2936 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2937</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2938
2939<p>Note that it is undefined to access an array out of bounds: array and
2940pointer indexes must always be within the defined bounds of the array type.
2941The one exception for this rules is zero length arrays. These arrays are
2942defined to be accessible as variable length arrays, which requires access
2943beyond the zero'th element.</p>
2944
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2945<p>The getelementptr instruction is often confusing. For some more insight
2946into how it works, see <a href="GetElementPtr.html">the getelementptr
2947FAQ</a>.</p>
2948
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2949<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2950
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2951<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2952 <i>; yields [12 x i8]*:aptr</i>
2953 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2954</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2955</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2956
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2957<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]2958<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2959</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2960<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]2961<p>The instructions in this category are the conversion instructions (casting)
2962which all take a single operand and a type. They perform various bit conversions
2963on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2964</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]2965
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2966<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]2967<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2968 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
2969</div>
2970<div class="doc_text">
2971
2972<h5>Syntax:</h5>
2973<pre>
2974 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2975</pre>
2976
2977<h5>Overview:</h5>
2978<p>
2979The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
2980</p>
2981
2982<h5>Arguments:</h5>
2983<p>
2984The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
2985be 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]2986and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2987type. The bit size of <tt>value</tt> must be larger than the bit size of
2988<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2989
2990<h5>Semantics:</h5>
2991<p>
2992The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2993and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
2994larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
2995It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2996
2997<h5>Example:</h5>
2998<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2999 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3000 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3001 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3002</pre>
3003</div>
3004
3005<!-- _______________________________________________________________________ -->
3006<div class="doc_subsubsection">
3007 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3008</div>
3009<div class="doc_text">
3010
3011<h5>Syntax:</h5>
3012<pre>
3013 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3014</pre>
3015
3016<h5>Overview:</h5>
3017<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3018<tt>ty2</tt>.</p>
3019
3020
3021<h5>Arguments:</h5>
3022<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]3023<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3024also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3025<tt>value</tt> must be smaller than the bit size of the destination type,
3026<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3027
3028<h5>Semantics:</h5>
3029<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]3030bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3031
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3032<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]3033
3034<h5>Example:</h5>
3035<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3036 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3037 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3038</pre>
3039</div>
3040
3041<!-- _______________________________________________________________________ -->
3042<div class="doc_subsubsection">
3043 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3044</div>
3045<div class="doc_text">
3046
3047<h5>Syntax:</h5>
3048<pre>
3049 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3050</pre>
3051
3052<h5>Overview:</h5>
3053<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3054
3055<h5>Arguments:</h5>
3056<p>
3057The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3058<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3059also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3060<tt>value</tt> must be smaller than the bit size of the destination type,
3061<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3062
3063<h5>Semantics:</h5>
3064<p>
3065The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3066bit (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]3067the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3068
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3069<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]3070
3071<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3072<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3073 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3074 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3075</pre>
3076</div>
3077
3078<!-- _______________________________________________________________________ -->
3079<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3080 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3081</div>
3082
3083<div class="doc_text">
3084
3085<h5>Syntax:</h5>
3086
3087<pre>
3088 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3089</pre>
3090
3091<h5>Overview:</h5>
3092<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3093<tt>ty2</tt>.</p>
3094
3095
3096<h5>Arguments:</h5>
3097<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3098 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3099cast it to. The size of <tt>value</tt> must be larger than the size of
3100<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3101<i>no-op cast</i>.</p>
3102
3103<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3104<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3105<a href="#t_floating">floating point</a> type to a smaller
3106<a href="#t_floating">floating point</a> type. If the value cannot fit within
3107the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3108
3109<h5>Example:</h5>
3110<pre>
3111 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3112 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3113</pre>
3114</div>
3115
3116<!-- _______________________________________________________________________ -->
3117<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3118 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3119</div>
3120<div class="doc_text">
3121
3122<h5>Syntax:</h5>
3123<pre>
3124 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3125</pre>
3126
3127<h5>Overview:</h5>
3128<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3129floating point value.</p>
3130
3131<h5>Arguments:</h5>
3132<p>The '<tt>fpext</tt>' instruction takes a
3133<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3134and a <a href="#t_floating">floating point</a> type to cast it to. The source
3135type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3136
3137<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3138<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3139<a href="#t_floating">floating point</a> type to a larger
3140<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3141used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3142<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]3143
3144<h5>Example:</h5>
3145<pre>
3146 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3147 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3148</pre>
3149</div>
3150
3151<!-- _______________________________________________________________________ -->
3152<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3153 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3154</div>
3155<div class="doc_text">
3156
3157<h5>Syntax:</h5>
3158<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3159 &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]3160</pre>
3161
3162<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3163<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3164unsigned integer equivalent of type <tt>ty2</tt>.
3165</p>
3166
3167<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3168<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]3169scalar or vector <a href="#t_floating">floating point</a> value, and a type
3170to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3171type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3172vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3173
3174<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3175<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3176<a href="#t_floating">floating point</a> operand into the nearest (rounding
3177towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3178the results are undefined.</p>
3179
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3180<h5>Example:</h5>
3181<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3182 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3183 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3184 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3185</pre>
3186</div>
3187
3188<!-- _______________________________________________________________________ -->
3189<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3190 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3191</div>
3192<div class="doc_text">
3193
3194<h5>Syntax:</h5>
3195<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3196 &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]3197</pre>
3198
3199<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3200<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3201<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]3202</p>
3203
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3204<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3205<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]3206scalar or vector <a href="#t_floating">floating point</a> value, and a type
3207to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3208type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3209vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3210
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3211<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3212<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3213<a href="#t_floating">floating point</a> operand into the nearest (rounding
3214towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3215the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3216
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3217<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3218<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3219 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3220 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3221 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3222</pre>
3223</div>
3224
3225<!-- _______________________________________________________________________ -->
3226<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3227 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3228</div>
3229<div class="doc_text">
3230
3231<h5>Syntax:</h5>
3232<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3233 &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]3234</pre>
3235
3236<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3237<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3238integer and converts that value to the <tt>ty2</tt> type.</p>
3239
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3240<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3241<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3242scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3243to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3244type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3245floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3246
3247<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3248<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3249integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3250the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3251
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3252<h5>Example:</h5>
3253<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3254 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3255 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3256</pre>
3257</div>
3258
3259<!-- _______________________________________________________________________ -->
3260<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3261 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3262</div>
3263<div class="doc_text">
3264
3265<h5>Syntax:</h5>
3266<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3267 &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]3268</pre>
3269
3270<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3271<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3272integer and converts that value to the <tt>ty2</tt> type.</p>
3273
3274<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3275<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3276scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3277to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3278type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3279floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3280
3281<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3282<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3283integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3284the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3285
3286<h5>Example:</h5>
3287<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3288 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3289 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3290</pre>
3291</div>
3292
3293<!-- _______________________________________________________________________ -->
3294<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3295 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3296</div>
3297<div class="doc_text">
3298
3299<h5>Syntax:</h5>
3300<pre>
3301 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3302</pre>
3303
3304<h5>Overview:</h5>
3305<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3306the integer type <tt>ty2</tt>.</p>
3307
3308<h5>Arguments:</h5>
3309<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3310must 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]3311<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3312
3313<h5>Semantics:</h5>
3314<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3315<tt>ty2</tt> by interpreting the pointer value as an integer and either
3316truncating or zero extending that value to the size of the integer type. If
3317<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3318<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]3319are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3320change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3321
3322<h5>Example:</h5>
3323<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3324 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3325 %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]3326</pre>
3327</div>
3328
3329<!-- _______________________________________________________________________ -->
3330<div class="doc_subsubsection">
3331 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3332</div>
3333<div class="doc_text">
3334
3335<h5>Syntax:</h5>
3336<pre>
3337 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3338</pre>
3339
3340<h5>Overview:</h5>
3341<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3342a pointer type, <tt>ty2</tt>.</p>
3343
3344<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3345<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3346value to cast, and a type to cast it to, which must be a
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]3347<a href="#t_pointer">pointer</a> type.
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3348
3349<h5>Semantics:</h5>
3350<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3351<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3352the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3353size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3354the size of a pointer then a zero extension is done. If they are the same size,
3355nothing is done (<i>no-op cast</i>).</p>
3356
3357<h5>Example:</h5>
3358<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3359 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3360 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3361 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3362</pre>
3363</div>
3364
3365<!-- _______________________________________________________________________ -->
3366<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3367 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3368</div>
3369<div class="doc_text">
3370
3371<h5>Syntax:</h5>
3372<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3373 &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]3374</pre>
3375
3376<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3377<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3378<tt>ty2</tt> without changing any bits.</p>
3379
3380<h5>Arguments:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3381<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3382a first class value, and a type to cast it to, which must also be a <a
3383 href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]3384and the destination type, <tt>ty2</tt>, must be identical. If the source
3385type is a pointer, the destination type must also be a pointer.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3386
3387<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3388<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3389<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3390this conversion. The conversion is done as if the <tt>value</tt> had been
3391stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3392converted to other pointer types with this instruction. To convert pointers to
3393other types, use the <a href="#i_inttoptr">inttoptr</a> or
3394<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3395
3396<h5>Example:</h5>
3397<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3398 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3399 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3400 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3401</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3402</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3403
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3404<!-- ======================================================================= -->
3405<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3406<div class="doc_text">
3407<p>The instructions in this category are the "miscellaneous"
3408instructions, which defy better classification.</p>
3409</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3410
3411<!-- _______________________________________________________________________ -->
3412<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3413</div>
3414<div class="doc_text">
3415<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3416<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]3417</pre>
3418<h5>Overview:</h5>
3419<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
3420of its two integer operands.</p>
3421<h5>Arguments:</h5>
3422<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3423the condition code indicating the kind of comparison to perform. It is not
3424a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3425<ol>
3426 <li><tt>eq</tt>: equal</li>
3427 <li><tt>ne</tt>: not equal </li>
3428 <li><tt>ugt</tt>: unsigned greater than</li>
3429 <li><tt>uge</tt>: unsigned greater or equal</li>
3430 <li><tt>ult</tt>: unsigned less than</li>
3431 <li><tt>ule</tt>: unsigned less or equal</li>
3432 <li><tt>sgt</tt>: signed greater than</li>
3433 <li><tt>sge</tt>: signed greater or equal</li>
3434 <li><tt>slt</tt>: signed less than</li>
3435 <li><tt>sle</tt>: signed less or equal</li>
3436</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3437<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3438<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3439<h5>Semantics:</h5>
3440<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3441the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3442yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3443<ol>
3444 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3445 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3446 </li>
3447 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3448 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3449 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
3450 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3451 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
3452 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3453 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
3454 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3455 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
3456 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
3457 <li><tt>sgt</tt>: interprets the operands as signed values and yields
3458 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3459 <li><tt>sge</tt>: interprets the operands as signed values and yields
3460 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3461 <li><tt>slt</tt>: interprets the operands as signed values and yields
3462 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3463 <li><tt>sle</tt>: interprets the operands as signed values and yields
3464 <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]3465</ol>
3466<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3467values are compared as if they were integers.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3468
3469<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3470<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3471 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3472 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3473 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3474 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3475 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3476</pre>
3477</div>
3478
3479<!-- _______________________________________________________________________ -->
3480<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3481</div>
3482<div class="doc_text">
3483<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3484<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]3485</pre>
3486<h5>Overview:</h5>
3487<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
3488of its floating point operands.</p>
3489<h5>Arguments:</h5>
3490<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3491the condition code indicating the kind of comparison to perform. It is not
3492a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3493<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3494 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3495 <li><tt>oeq</tt>: ordered and equal</li>
3496 <li><tt>ogt</tt>: ordered and greater than </li>
3497 <li><tt>oge</tt>: ordered and greater than or equal</li>
3498 <li><tt>olt</tt>: ordered and less than </li>
3499 <li><tt>ole</tt>: ordered and less than or equal</li>
3500 <li><tt>one</tt>: ordered and not equal</li>
3501 <li><tt>ord</tt>: ordered (no nans)</li>
3502 <li><tt>ueq</tt>: unordered or equal</li>
3503 <li><tt>ugt</tt>: unordered or greater than </li>
3504 <li><tt>uge</tt>: unordered or greater than or equal</li>
3505 <li><tt>ult</tt>: unordered or less than </li>
3506 <li><tt>ule</tt>: unordered or less than or equal</li>
3507 <li><tt>une</tt>: unordered or not equal</li>
3508 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3509 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3510</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3511<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]3512<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3513<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
3514<a href="#t_floating">floating point</a> typed. They must have identical
3515types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3516<h5>Semantics:</h5>
3517<p>The '<tt>fcmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3518the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3519yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3520<ol>
3521 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3522 <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]3523 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3524 <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]3525 <tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3526 <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]3527 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3528 <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]3529 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3530 <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]3531 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3532 <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]3533 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3534 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3535 <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]3536 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3537 <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]3538 <tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3539 <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]3540 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3541 <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]3542 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3543 <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]3544 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3545 <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]3546 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3547 <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]3548 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
3549</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3550
3551<h5>Example:</h5>
3552<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
3553 &lt;result&gt; = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
3554 &lt;result&gt; = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
3555 &lt;result&gt; = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
3556</pre>
3557</div>
3558
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3559<!-- _______________________________________________________________________ -->
3560<div class="doc_subsubsection"> <a name="i_phi">'<tt>phi</tt>'
3561Instruction</a> </div>
3562<div class="doc_text">
3563<h5>Syntax:</h5>
3564<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
3565<h5>Overview:</h5>
3566<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
3567the SSA graph representing the function.</p>
3568<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3569<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3570field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
3571as arguments, with one pair for each predecessor basic block of the
3572current block. Only values of <a href="#t_firstclass">first class</a>
3573type may be used as the value arguments to the PHI node. Only labels
3574may be used as the label arguments.</p>
3575<p>There must be no non-phi instructions between the start of a basic
3576block and the PHI instructions: i.e. PHI instructions must be first in
3577a basic block.</p>
3578<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3579<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
3580specified by the pair corresponding to the predecessor basic block that executed
3581just prior to the current block.</p>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3582<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3583<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]3584</div>
3585
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3586<!-- _______________________________________________________________________ -->
3587<div class="doc_subsubsection">
3588 <a name="i_select">'<tt>select</tt>' Instruction</a>
3589</div>
3590
3591<div class="doc_text">
3592
3593<h5>Syntax:</h5>
3594
3595<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3596 &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]3597</pre>
3598
3599<h5>Overview:</h5>
3600
3601<p>
3602The '<tt>select</tt>' instruction is used to choose one value based on a
3603condition, without branching.
3604</p>
3605
3606
3607<h5>Arguments:</h5>
3608
3609<p>
3610The '<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.
3611</p>
3612
3613<h5>Semantics:</h5>
3614
3615<p>
3616If the boolean condition evaluates to true, the instruction returns the first
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3617value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3618</p>
3619
3620<h5>Example:</h5>
3621
3622<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3623 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3624</pre>
3625</div>
3626
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]3627
3628<!-- _______________________________________________________________________ -->
3629<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3630 <a name="i_call">'<tt>call</tt>' Instruction</a>
3631</div>
3632
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3633<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3634
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3635<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3636<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3637 &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]3638</pre>
3639
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3640<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3641
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3642<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3643
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3644<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3645
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3646<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3647
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3648<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3649 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3650 <p>The optional "tail" marker indicates whether the callee function accesses
3651 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3652 function call is eligible for tail call optimization. Note that calls may
3653 be marked "tail" even if they do not occur before a <a
3654 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3655 </li>
3656 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3657 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3658 convention</a> the call should use. If none is specified, the call defaults
3659 to using C calling conventions.
3660 </li>
3661 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3662 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
3663 the type of the return value. Functions that return no value are marked
3664 <tt><a href="#t_void">void</a></tt>.</p>
3665 </li>
3666 <li>
3667 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
3668 value being invoked. The argument types must match the types implied by
3669 this signature. This type can be omitted if the function is not varargs
3670 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3671 </li>
3672 <li>
3673 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
3674 be invoked. In most cases, this is a direct function invocation, but
3675 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3676 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3677 </li>
3678 <li>
3679 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]3680 function signature argument types. All arguments must be of
3681 <a href="#t_firstclass">first class</a> type. If the function signature
3682 indicates the function accepts a variable number of arguments, the extra
3683 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3684 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3685</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3686
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3687<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3688
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3689<p>The '<tt>call</tt>' instruction is used to cause control flow to
3690transfer to a specified function, with its incoming arguments bound to
3691the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
3692instruction in the called function, control flow continues with the
3693instruction after the function call, and the return value of the
3694function is bound to the result argument. This is a simpler case of
3695the <a href="#i_invoke">invoke</a> instruction.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3696
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3697<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3698
3699<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3700 %retval = call i32 @test(i32 %argc)
3701 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42);
3702 %X = tail call i32 @foo()
3703 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo()
3704 %Z = call void %foo(i8 97 signext)
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3705</pre>
3706
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3707</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3708
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3709<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3710<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3711 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3712</div>
3713
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3714<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3715
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3716<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3717
3718<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3719 &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]3720</pre>
3721
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3722<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3723
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3724<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3725the "variable argument" area of a function call. It is used to implement the
3726<tt>va_arg</tt> macro in C.</p>
3727
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3728<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3729
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3730<p>This instruction takes a <tt>va_list*</tt> value and the type of
3731the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3732increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3733actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3734
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3735<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3736
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3737<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
3738type from the specified <tt>va_list</tt> and causes the
3739<tt>va_list</tt> to point to the next argument. For more information,
3740see the variable argument handling <a href="#int_varargs">Intrinsic
3741Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3742
3743<p>It is legal for this instruction to be called in a function which does not
3744take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3745function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3746
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3747<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3748href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3749argument.</p>
3750
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3751<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3752
3753<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
3754
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3755</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3756
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3757<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3758<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
3759<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3760
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3761<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3762
3763<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3764well known names and semantics and are required to follow certain restrictions.
3765Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3766language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]3767adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3768
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3769<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3770prefix is reserved in LLVM for intrinsic names; thus, function names may not
3771begin with this prefix. Intrinsic functions must always be external functions:
3772you cannot define the body of intrinsic functions. Intrinsic functions may
3773only be used in call or invoke instructions: it is illegal to take the address
3774of an intrinsic function. Additionally, because intrinsic functions are part
3775of the LLVM language, it is required if any are added that they be documented
3776here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3777
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]3778<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
3779a family of functions that perform the same operation but on different data
3780types. Because LLVM can represent over 8 million different integer types,
3781overloading is used commonly to allow an intrinsic function to operate on any
3782integer type. One or more of the argument types or the result type can be
3783overloaded to accept any integer type. Argument types may also be defined as
3784exactly matching a previous argument's type or the result type. This allows an
3785intrinsic function which accepts multiple arguments, but needs all of them to
3786be of the same type, to only be overloaded with respect to a single argument or
3787the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3788
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]3789<p>Overloaded intrinsics will have the names of its overloaded argument types
3790encoded into its function name, each preceded by a period. Only those types
3791which are overloaded result in a name suffix. Arguments whose type is matched
3792against another type do not. For example, the <tt>llvm.ctpop</tt> function can
3793take an integer of any width and returns an integer of exactly the same integer
3794width. This leads to a family of functions such as
3795<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
3796Only one type, the return type, is overloaded, and only one type suffix is
3797required. Because the argument's type is matched against the return type, it
3798does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3799
3800<p>To learn how to add an intrinsic function, please see the
3801<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3802</p>
3803
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3804</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3805
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3806<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3807<div class="doc_subsection">
3808 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
3809</div>
3810
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3811<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3812
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3813<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3814 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3815intrinsic functions. These functions are related to the similarly
3816named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3817
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3818<p>All of these functions operate on arguments that use a
3819target-specific value type "<tt>va_list</tt>". The LLVM assembly
3820language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3821transformations should be prepared to handle these functions regardless of
3822the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3823
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]3824<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]3825instruction and the variable argument handling intrinsic functions are
3826used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3827
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3828<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3829<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3830define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3831 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3832 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3833 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3834 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3835
3836 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3837 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3838
3839 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3840 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3841 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3842 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3843 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3844
3845 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3846 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3847 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3848}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3849
3850declare void @llvm.va_start(i8*)
3851declare void @llvm.va_copy(i8*, i8*)
3852declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3853</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3854</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3855
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3856</div>
3857
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3858<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3859<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3860 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3861</div>
3862
3863
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3864<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3865<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3866<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3867<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3868<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
3869<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
3870href="#i_va_arg">va_arg</a></tt>.</p>
3871
3872<h5>Arguments:</h5>
3873
3874<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
3875
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3876<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3877
3878<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
3879macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3880<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]3881<tt>va_arg</tt> will produce the first variable argument passed to the function.
3882Unlike 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]3883last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3884
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3885</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3886
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3887<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3888<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3889 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3890</div>
3891
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3892<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3893<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3894<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3895<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3896
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3897<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3898which 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]3899or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3900
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3901<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3902
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3903<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3904
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3905<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3906
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3907<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]3908macro available in C. In a target-dependent way, it destroys the
3909<tt>va_list</tt> element to which the argument points. Calls to <a
3910href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
3911<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
3912<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3913
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3914</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3915
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3916<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3917<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3918 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3919</div>
3920
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3921<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3922
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3923<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3924
3925<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3926 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3927</pre>
3928
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3929<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3930
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3931<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
3932from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3933
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3934<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3935
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3936<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]3937The 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]3938
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3939
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3940<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3941
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3942<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
3943macro available in C. In a target-dependent way, it copies the source
3944<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
3945intrinsic is necessary because the <tt><a href="#int_va_start">
3946llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
3947example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3948
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3949</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3950
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3951<!-- ======================================================================= -->
3952<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3953 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
3954</div>
3955
3956<div class="doc_text">
3957
3958<p>
3959LLVM support for <a href="GarbageCollection.html">Accurate Garbage
3960Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3961These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3962stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3963href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3964Front-ends for type-safe garbage collected languages should generate these
3965intrinsics to make use of the LLVM garbage collectors. For more details, see <a
3966href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
3967</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]3968
3969<p>The garbage collection intrinsics only operate on objects in the generic
3970 address space (address space zero).</p>
3971
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3972</div>
3973
3974<!-- _______________________________________________________________________ -->
3975<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3976 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3977</div>
3978
3979<div class="doc_text">
3980
3981<h5>Syntax:</h5>
3982
3983<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]3984 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3985</pre>
3986
3987<h5>Overview:</h5>
3988
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3989<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]3990the code generator, and allows some metadata to be associated with it.</p>
3991
3992<h5>Arguments:</h5>
3993
3994<p>The first argument specifies the address of a stack object that contains the
3995root pointer. The second pointer (which must be either a constant or a global
3996value address) contains the meta-data to be associated with the root.</p>
3997
3998<h5>Semantics:</h5>
3999
4000<p>At runtime, a call to this intrinsics stores a null pointer into the "ptrloc"
4001location. At compile-time, the code generator generates information to allow
4002the runtime to find the pointer at GC safe points.
4003</p>
4004
4005</div>
4006
4007
4008<!-- _______________________________________________________________________ -->
4009<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4010 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4011</div>
4012
4013<div class="doc_text">
4014
4015<h5>Syntax:</h5>
4016
4017<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4018 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4019</pre>
4020
4021<h5>Overview:</h5>
4022
4023<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4024locations, allowing garbage collector implementations that require read
4025barriers.</p>
4026
4027<h5>Arguments:</h5>
4028
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4029<p>The second argument is the address to read from, which should be an address
4030allocated from the garbage collector. The first object is a pointer to the
4031start of the referenced object, if needed by the language runtime (otherwise
4032null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4033
4034<h5>Semantics:</h5>
4035
4036<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4037instruction, but may be replaced with substantially more complex code by the
4038garbage collector runtime, as needed.</p>
4039
4040</div>
4041
4042
4043<!-- _______________________________________________________________________ -->
4044<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4045 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4046</div>
4047
4048<div class="doc_text">
4049
4050<h5>Syntax:</h5>
4051
4052<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4053 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4054</pre>
4055
4056<h5>Overview:</h5>
4057
4058<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4059locations, allowing garbage collector implementations that require write
4060barriers (such as generational or reference counting collectors).</p>
4061
4062<h5>Arguments:</h5>
4063
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4064<p>The first argument is the reference to store, the second is the start of the
4065object to store it to, and the third is the address of the field of Obj to
4066store to. If the runtime does not require a pointer to the object, Obj may be
4067null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4068
4069<h5>Semantics:</h5>
4070
4071<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4072instruction, but may be replaced with substantially more complex code by the
4073garbage collector runtime, as needed.</p>
4074
4075</div>
4076
4077
4078
4079<!-- ======================================================================= -->
4080<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4081 <a name="int_codegen">Code Generator Intrinsics</a>
4082</div>
4083
4084<div class="doc_text">
4085<p>
4086These intrinsics are provided by LLVM to expose special features that may only
4087be implemented with code generator support.
4088</p>
4089
4090</div>
4091
4092<!-- _______________________________________________________________________ -->
4093<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4094 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4095</div>
4096
4097<div class="doc_text">
4098
4099<h5>Syntax:</h5>
4100<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4101 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4102</pre>
4103
4104<h5>Overview:</h5>
4105
4106<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4107The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4108target-specific value indicating the return address of the current function
4109or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4110</p>
4111
4112<h5>Arguments:</h5>
4113
4114<p>
4115The argument to this intrinsic indicates which function to return the address
4116for. Zero indicates the calling function, one indicates its caller, etc. The
4117argument is <b>required</b> to be a constant integer value.
4118</p>
4119
4120<h5>Semantics:</h5>
4121
4122<p>
4123The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4124the return address of the specified call frame, or zero if it cannot be
4125identified. The value returned by this intrinsic is likely to be incorrect or 0
4126for arguments other than zero, so it should only be used for debugging purposes.
4127</p>
4128
4129<p>
4130Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4131aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4132source-language caller.
4133</p>
4134</div>
4135
4136
4137<!-- _______________________________________________________________________ -->
4138<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4139 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4140</div>
4141
4142<div class="doc_text">
4143
4144<h5>Syntax:</h5>
4145<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4146 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4147</pre>
4148
4149<h5>Overview:</h5>
4150
4151<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4152The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4153target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4154</p>
4155
4156<h5>Arguments:</h5>
4157
4158<p>
4159The argument to this intrinsic indicates which function to return the frame
4160pointer for. Zero indicates the calling function, one indicates its caller,
4161etc. The argument is <b>required</b> to be a constant integer value.
4162</p>
4163
4164<h5>Semantics:</h5>
4165
4166<p>
4167The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4168the frame address of the specified call frame, or zero if it cannot be
4169identified. The value returned by this intrinsic is likely to be incorrect or 0
4170for arguments other than zero, so it should only be used for debugging purposes.
4171</p>
4172
4173<p>
4174Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4175aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4176source-language caller.
4177</p>
4178</div>
4179
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4180<!-- _______________________________________________________________________ -->
4181<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4182 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4183</div>
4184
4185<div class="doc_text">
4186
4187<h5>Syntax:</h5>
4188<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4189 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4190</pre>
4191
4192<h5>Overview:</h5>
4193
4194<p>
4195The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4196the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4197<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4198features like scoped automatic variable sized arrays in C99.
4199</p>
4200
4201<h5>Semantics:</h5>
4202
4203<p>
4204This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4205href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4206<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4207<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4208state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4209practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4210that were allocated after the <tt>llvm.stacksave</tt> was executed.
4211</p>
4212
4213</div>
4214
4215<!-- _______________________________________________________________________ -->
4216<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4217 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4218</div>
4219
4220<div class="doc_text">
4221
4222<h5>Syntax:</h5>
4223<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4224 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4225</pre>
4226
4227<h5>Overview:</h5>
4228
4229<p>
4230The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4231the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4232href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4233useful for implementing language features like scoped automatic variable sized
4234arrays in C99.
4235</p>
4236
4237<h5>Semantics:</h5>
4238
4239<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4240See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4241</p>
4242
4243</div>
4244
4245
4246<!-- _______________________________________________________________________ -->
4247<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4248 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4249</div>
4250
4251<div class="doc_text">
4252
4253<h5>Syntax:</h5>
4254<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4255 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]4256</pre>
4257
4258<h5>Overview:</h5>
4259
4260
4261<p>
4262The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4263a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4264no
4265effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]4266characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4267</p>
4268
4269<h5>Arguments:</h5>
4270
4271<p>
4272<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4273determining if the fetch should be for a read (0) or write (1), and
4274<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]4275locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4276<tt>locality</tt> arguments must be constant integers.
4277</p>
4278
4279<h5>Semantics:</h5>
4280
4281<p>
4282This intrinsic does not modify the behavior of the program. In particular,
4283prefetches cannot trap and do not produce a value. On targets that support this
4284intrinsic, the prefetch can provide hints to the processor cache for better
4285performance.
4286</p>
4287
4288</div>
4289
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4290<!-- _______________________________________________________________________ -->
4291<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4292 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4293</div>
4294
4295<div class="doc_text">
4296
4297<h5>Syntax:</h5>
4298<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4299 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4300</pre>
4301
4302<h5>Overview:</h5>
4303
4304
4305<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4306The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
4307(PC) in a region of
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4308code to simulators and other tools. The method is target specific, but it is
4309expected that the marker will use exported symbols to transmit the PC of the marker.
Jeff Cohen25d4f7e2005-11-11 02:15:27 +0000[diff] [blame]4310The marker makes no guarantees that it will remain with any specific instruction
Chris Lattnerd07c3f42005-11-15 06:07:55 +0000[diff] [blame]4311after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]4312optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4313correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4314</p>
4315
4316<h5>Arguments:</h5>
4317
4318<p>
4319<tt>id</tt> is a numerical id identifying the marker.
4320</p>
4321
4322<h5>Semantics:</h5>
4323
4324<p>
4325This intrinsic does not modify the behavior of the program. Backends that do not
4326support this intrinisic may ignore it.
4327</p>
4328
4329</div>
4330
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4331<!-- _______________________________________________________________________ -->
4332<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4333 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4334</div>
4335
4336<div class="doc_text">
4337
4338<h5>Syntax:</h5>
4339<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4340 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4341</pre>
4342
4343<h5>Overview:</h5>
4344
4345
4346<p>
4347The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4348counter register (or similar low latency, high accuracy clocks) on those targets
4349that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4350As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4351should only be used for small timings.
4352</p>
4353
4354<h5>Semantics:</h5>
4355
4356<p>
4357When directly supported, reading the cycle counter should not modify any memory.
4358Implementations are allowed to either return a application specific value or a
4359system wide value. On backends without support, this is lowered to a constant 0.
4360</p>
4361
4362</div>
4363
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4364<!-- ======================================================================= -->
4365<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4366 <a name="int_libc">Standard C Library Intrinsics</a>
4367</div>
4368
4369<div class="doc_text">
4370<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4371LLVM provides intrinsics for a few important standard C library functions.
4372These intrinsics allow source-language front-ends to pass information about the
4373alignment of the pointer arguments to the code generator, providing opportunity
4374for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4375</p>
4376
4377</div>
4378
4379<!-- _______________________________________________________________________ -->
4380<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4381 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4382</div>
4383
4384<div class="doc_text">
4385
4386<h5>Syntax:</h5>
4387<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4388 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4389 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4390 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4391 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4392</pre>
4393
4394<h5>Overview:</h5>
4395
4396<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4397The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4398location to the destination location.
4399</p>
4400
4401<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4402Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
4403intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4404</p>
4405
4406<h5>Arguments:</h5>
4407
4408<p>
4409The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4410the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4411specifying the number of bytes to copy, and the fourth argument is the alignment
4412of the source and destination locations.
4413</p>
4414
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4415<p>
4416If 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]4417the caller guarantees that both the source and destination pointers are aligned
4418to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4419</p>
4420
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4421<h5>Semantics:</h5>
4422
4423<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4424The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4425location to the destination location, which are not allowed to overlap. It
4426copies "len" bytes of memory over. If the argument is known to be aligned to
4427some boundary, this can be specified as the fourth argument, otherwise it should
4428be set to 0 or 1.
4429</p>
4430</div>
4431
4432
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4433<!-- _______________________________________________________________________ -->
4434<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4435 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4436</div>
4437
4438<div class="doc_text">
4439
4440<h5>Syntax:</h5>
4441<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4442 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4443 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4444 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4445 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4446</pre>
4447
4448<h5>Overview:</h5>
4449
4450<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4451The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
4452location to the destination location. It is similar to the
4453'<tt>llvm.memcmp</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4454</p>
4455
4456<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4457Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
4458intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4459</p>
4460
4461<h5>Arguments:</h5>
4462
4463<p>
4464The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4465the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4466specifying the number of bytes to copy, and the fourth argument is the alignment
4467of the source and destination locations.
4468</p>
4469
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4470<p>
4471If 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]4472the caller guarantees that the source and destination pointers are aligned to
4473that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4474</p>
4475
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4476<h5>Semantics:</h5>
4477
4478<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4479The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4480location to the destination location, which may overlap. It
4481copies "len" bytes of memory over. If the argument is known to be aligned to
4482some boundary, this can be specified as the fourth argument, otherwise it should
4483be set to 0 or 1.
4484</p>
4485</div>
4486
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4487
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4488<!-- _______________________________________________________________________ -->
4489<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4490 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4491</div>
4492
4493<div class="doc_text">
4494
4495<h5>Syntax:</h5>
4496<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4497 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4498 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4499 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4500 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4501</pre>
4502
4503<h5>Overview:</h5>
4504
4505<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4506The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4507byte value.
4508</p>
4509
4510<p>
4511Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
4512does not return a value, and takes an extra alignment argument.
4513</p>
4514
4515<h5>Arguments:</h5>
4516
4517<p>
4518The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4519byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4520argument specifying the number of bytes to fill, and the fourth argument is the
4521known alignment of destination location.
4522</p>
4523
4524<p>
4525If 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]4526the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4527</p>
4528
4529<h5>Semantics:</h5>
4530
4531<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4532The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
4533the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4534destination location. If the argument is known to be aligned to some boundary,
4535this can be specified as the fourth argument, otherwise it should be set to 0 or
45361.
4537</p>
4538</div>
4539
4540
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4541<!-- _______________________________________________________________________ -->
4542<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4543 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4544</div>
4545
4546<div class="doc_text">
4547
4548<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4549<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]4550floating point or vector of floating point type. Not all targets support all
4551types however.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4552<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4553 declare float @llvm.sqrt.f32(float %Val)
4554 declare double @llvm.sqrt.f64(double %Val)
4555 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
4556 declare fp128 @llvm.sqrt.f128(fp128 %Val)
4557 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4558</pre>
4559
4560<h5>Overview:</h5>
4561
4562<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4563The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4564returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4565<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
4566negative numbers (which allows for better optimization).
4567</p>
4568
4569<h5>Arguments:</h5>
4570
4571<p>
4572The argument and return value are floating point numbers of the same type.
4573</p>
4574
4575<h5>Semantics:</h5>
4576
4577<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]4578This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4579floating point number.
4580</p>
4581</div>
4582
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4583<!-- _______________________________________________________________________ -->
4584<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4585 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4586</div>
4587
4588<div class="doc_text">
4589
4590<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4591<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]4592floating point or vector of floating point type. Not all targets support all
4593types however.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4594<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4595 declare float @llvm.powi.f32(float %Val, i32 %power)
4596 declare double @llvm.powi.f64(double %Val, i32 %power)
4597 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
4598 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
4599 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4600</pre>
4601
4602<h5>Overview:</h5>
4603
4604<p>
4605The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
4606specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4607multiplications is not defined. When a vector of floating point type is
4608used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4609</p>
4610
4611<h5>Arguments:</h5>
4612
4613<p>
4614The second argument is an integer power, and the first is a value to raise to
4615that power.
4616</p>
4617
4618<h5>Semantics:</h5>
4619
4620<p>
4621This function returns the first value raised to the second power with an
4622unspecified sequence of rounding operations.</p>
4623</div>
4624
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4625<!-- _______________________________________________________________________ -->
4626<div class="doc_subsubsection">
4627 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
4628</div>
4629
4630<div class="doc_text">
4631
4632<h5>Syntax:</h5>
4633<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
4634floating point or vector of floating point type. Not all targets support all
4635types however.
4636<pre>
4637 declare float @llvm.sin.f32(float %Val)
4638 declare double @llvm.sin.f64(double %Val)
4639 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
4640 declare fp128 @llvm.sin.f128(fp128 %Val)
4641 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
4642</pre>
4643
4644<h5>Overview:</h5>
4645
4646<p>
4647The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
4648</p>
4649
4650<h5>Arguments:</h5>
4651
4652<p>
4653The argument and return value are floating point numbers of the same type.
4654</p>
4655
4656<h5>Semantics:</h5>
4657
4658<p>
4659This function returns the sine of the specified operand, returning the
4660same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4661conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4662</div>
4663
4664<!-- _______________________________________________________________________ -->
4665<div class="doc_subsubsection">
4666 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
4667</div>
4668
4669<div class="doc_text">
4670
4671<h5>Syntax:</h5>
4672<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
4673floating point or vector of floating point type. Not all targets support all
4674types however.
4675<pre>
4676 declare float @llvm.cos.f32(float %Val)
4677 declare double @llvm.cos.f64(double %Val)
4678 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
4679 declare fp128 @llvm.cos.f128(fp128 %Val)
4680 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
4681</pre>
4682
4683<h5>Overview:</h5>
4684
4685<p>
4686The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
4687</p>
4688
4689<h5>Arguments:</h5>
4690
4691<p>
4692The argument and return value are floating point numbers of the same type.
4693</p>
4694
4695<h5>Semantics:</h5>
4696
4697<p>
4698This function returns the cosine of the specified operand, returning the
4699same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4700conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4701</div>
4702
4703<!-- _______________________________________________________________________ -->
4704<div class="doc_subsubsection">
4705 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
4706</div>
4707
4708<div class="doc_text">
4709
4710<h5>Syntax:</h5>
4711<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
4712floating point or vector of floating point type. Not all targets support all
4713types however.
4714<pre>
4715 declare float @llvm.pow.f32(float %Val, float %Power)
4716 declare double @llvm.pow.f64(double %Val, double %Power)
4717 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
4718 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
4719 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
4720</pre>
4721
4722<h5>Overview:</h5>
4723
4724<p>
4725The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
4726specified (positive or negative) power.
4727</p>
4728
4729<h5>Arguments:</h5>
4730
4731<p>
4732The second argument is a floating point power, and the first is a value to
4733raise to that power.
4734</p>
4735
4736<h5>Semantics:</h5>
4737
4738<p>
4739This function returns the first value raised to the second power,
4740returning the
4741same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4742conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4743</div>
4744
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4745
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4746<!-- ======================================================================= -->
4747<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4748 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4749</div>
4750
4751<div class="doc_text">
4752<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4753LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4754These allow efficient code generation for some algorithms.
4755</p>
4756
4757</div>
4758
4759<!-- _______________________________________________________________________ -->
4760<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4761 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4762</div>
4763
4764<div class="doc_text">
4765
4766<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4767<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4768type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4769<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4770 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
4771 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
4772 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4773</pre>
4774
4775<h5>Overview:</h5>
4776
4777<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]4778The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4779values with an even number of bytes (positive multiple of 16 bits). These are
4780useful for performing operations on data that is not in the target's native
4781byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4782</p>
4783
4784<h5>Semantics:</h5>
4785
4786<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4787The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4788and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
4789intrinsic returns an i32 value that has the four bytes of the input i32
4790swapped, 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]4791i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
4792<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4793additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4794</p>
4795
4796</div>
4797
4798<!-- _______________________________________________________________________ -->
4799<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4800 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4801</div>
4802
4803<div class="doc_text">
4804
4805<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4806<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
4807width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4808<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4809 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
4810 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4811 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4812 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
4813 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4814</pre>
4815
4816<h5>Overview:</h5>
4817
4818<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]4819The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
4820value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4821</p>
4822
4823<h5>Arguments:</h5>
4824
4825<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4826The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4827integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4828</p>
4829
4830<h5>Semantics:</h5>
4831
4832<p>
4833The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
4834</p>
4835</div>
4836
4837<!-- _______________________________________________________________________ -->
4838<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4839 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4840</div>
4841
4842<div class="doc_text">
4843
4844<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4845<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
4846integer bit width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4847<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4848 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
4849 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4850 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4851 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
4852 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4853</pre>
4854
4855<h5>Overview:</h5>
4856
4857<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4858The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
4859leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4860</p>
4861
4862<h5>Arguments:</h5>
4863
4864<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4865The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4866integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4867</p>
4868
4869<h5>Semantics:</h5>
4870
4871<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4872The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
4873in 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]4874of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4875</p>
4876</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4877
4878
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4879
4880<!-- _______________________________________________________________________ -->
4881<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4882 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4883</div>
4884
4885<div class="doc_text">
4886
4887<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4888<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
4889integer bit width. Not all targets support all bit widths however.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4890<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4891 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
4892 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4893 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4894 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
4895 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4896</pre>
4897
4898<h5>Overview:</h5>
4899
4900<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4901The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
4902trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4903</p>
4904
4905<h5>Arguments:</h5>
4906
4907<p>
4908The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4909integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4910</p>
4911
4912<h5>Semantics:</h5>
4913
4914<p>
4915The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
4916in a variable. If the src == 0 then the result is the size in bits of the type
4917of src. For example, <tt>llvm.cttz(2) = 1</tt>.
4918</p>
4919</div>
4920
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]4921<!-- _______________________________________________________________________ -->
4922<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4923 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4924</div>
4925
4926<div class="doc_text">
4927
4928<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4929<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4930on any integer bit width.
4931<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4932 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
4933 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4934</pre>
4935
4936<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4937<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4938range of bits from an integer value and returns them in the same bit width as
4939the original value.</p>
4940
4941<h5>Arguments:</h5>
4942<p>The first argument, <tt>%val</tt> and the result may be integer types of
4943any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4944arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4945
4946<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4947<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4948of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
4949<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
4950operates in forward mode.</p>
4951<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
4952right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4953only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
4954<ol>
4955 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
4956 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
4957 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
4958 to determine the number of bits to retain.</li>
4959 <li>A mask of the retained bits is created by shifting a -1 value.</li>
4960 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
4961</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]4962<p>In reverse mode, a similar computation is made except that the bits are
4963returned in the reverse order. So, for example, if <tt>X</tt> has the value
4964<tt>i16 0x0ACF (101011001111)</tt> and we apply
4965<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
4966<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4967</div>
4968
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]4969<div class="doc_subsubsection">
4970 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
4971</div>
4972
4973<div class="doc_text">
4974
4975<h5>Syntax:</h5>
4976<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
4977on any integer bit width.
4978<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4979 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
4980 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]4981</pre>
4982
4983<h5>Overview:</h5>
4984<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
4985of bits in an integer value with another integer value. It returns the integer
4986with the replaced bits.</p>
4987
4988<h5>Arguments:</h5>
4989<p>The first argument, <tt>%val</tt> and the result may be integer types of
4990any bit width but they must have the same bit width. <tt>%val</tt> is the value
4991whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
4992integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
4993type since they specify only a bit index.</p>
4994
4995<h5>Semantics:</h5>
4996<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
4997of operation: forwards and reverse. If <tt>%lo</tt> is greater than
4998<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
4999operates in forward mode.</p>
5000<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5001truncating it down to the size of the replacement area or zero extending it
5002up to that size.</p>
5003<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5004are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5005in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
5006to the <tt>%hi</tt>th bit.
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5007<p>In reverse mode, a similar computation is made except that the bits are
5008reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
5009<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]5010<h5>Examples:</h5>
5011<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5012 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]5013 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5014 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5015 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]5016 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]5017</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]5018</div>
5019
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5020<!-- ======================================================================= -->
5021<div class="doc_subsection">
5022 <a name="int_debugger">Debugger Intrinsics</a>
5023</div>
5024
5025<div class="doc_text">
5026<p>
5027The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5028are described in the <a
5029href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5030Debugging</a> document.
5031</p>
5032</div>
5033
5034
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5035<!-- ======================================================================= -->
5036<div class="doc_subsection">
5037 <a name="int_eh">Exception Handling Intrinsics</a>
5038</div>
5039
5040<div class="doc_text">
5041<p> The LLVM exception handling intrinsics (which all start with
5042<tt>llvm.eh.</tt> prefix), are described in the <a
5043href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5044Handling</a> document. </p>
5045</div>
5046
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5047<!-- ======================================================================= -->
5048<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5049 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5050</div>
5051
5052<div class="doc_text">
5053<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5054 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5055 the <tt>nest</tt> attribute, from a function. The result is a callable
5056 function pointer lacking the nest parameter - the caller does not need
5057 to provide a value for it. Instead, the value to use is stored in
5058 advance in a "trampoline", a block of memory usually allocated
5059 on the stack, which also contains code to splice the nest value into the
5060 argument list. This is used to implement the GCC nested function address
5061 extension.
5062</p>
5063<p>
5064 For example, if the function is
5065 <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]5066 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]5067<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5068 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5069 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5070 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5071 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5072</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5073 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5074 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5075</div>
5076
5077<!-- _______________________________________________________________________ -->
5078<div class="doc_subsubsection">
5079 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5080</div>
5081<div class="doc_text">
5082<h5>Syntax:</h5>
5083<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5084declare 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]5085</pre>
5086<h5>Overview:</h5>
5087<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5088 This fills the memory pointed to by <tt>tramp</tt> with code
5089 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5090</p>
5091<h5>Arguments:</h5>
5092<p>
5093 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5094 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5095 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]5096 intrinsic. Note that the size and the alignment are target-specific - LLVM
5097 currently provides no portable way of determining them, so a front-end that
5098 generates this intrinsic needs to have some target-specific knowledge.
5099 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]5100</p>
5101<h5>Semantics:</h5>
5102<p>
5103 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5104 dependent code, turning it into a function. A pointer to this function is
5105 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5106 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5107 before being called. The new function's signature is the same as that of
5108 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5109 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5110 of pointer type. Calling the new function is equivalent to calling
5111 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5112 missing <tt>nest</tt> argument. If, after calling
5113 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5114 modified, then the effect of any later call to the returned function pointer is
5115 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5116</p>
5117</div>
5118
5119<!-- ======================================================================= -->
5120<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5121 <a name="int_general">General Intrinsics</a>
5122</div>
5123
5124<div class="doc_text">
5125<p> This class of intrinsics is designed to be generic and has
5126no specific purpose. </p>
5127</div>
5128
5129<!-- _______________________________________________________________________ -->
5130<div class="doc_subsubsection">
5131 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
5132</div>
5133
5134<div class="doc_text">
5135
5136<h5>Syntax:</h5>
5137<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]5138 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]5139</pre>
5140
5141<h5>Overview:</h5>
5142
5143<p>
5144The '<tt>llvm.var.annotation</tt>' intrinsic
5145</p>
5146
5147<h5>Arguments:</h5>
5148
5149<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]5150The first argument is a pointer to a value, the second is a pointer to a
5151global string, the third is a pointer to a global string which is the source
5152file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5153</p>
5154
5155<h5>Semantics:</h5>
5156
5157<p>
5158This intrinsic allows annotation of local variables with arbitrary strings.
5159This can be useful for special purpose optimizations that want to look for these
5160 annotations. These have no other defined use, they are ignored by code
5161 generation and optimization.
5162</div>
5163
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5164<!-- _______________________________________________________________________ -->
5165<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]5166 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5167</div>
5168
5169<div class="doc_text">
5170
5171<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5172<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
5173any integer bit width.
5174</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5175<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]5176 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5177 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5178 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5179 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5180 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]5181</pre>
5182
5183<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5184
5185<p>
5186The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5187</p>
5188
5189<h5>Arguments:</h5>
5190
5191<p>
5192The first argument is an integer value (result of some expression),
5193the second is a pointer to a global string, the third is a pointer to a global
5194string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5195It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5196</p>
5197
5198<h5>Semantics:</h5>
5199
5200<p>
5201This intrinsic allows annotations to be put on arbitrary expressions
5202with arbitrary strings. This can be useful for special purpose optimizations
5203that want to look for these annotations. These have no other defined use, they
5204are ignored by code generation and optimization.
5205</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5206
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5207<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5208<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]5209<address>
5210 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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5214
5215 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]5216 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]5217 Last modified: $Date$
5218</address>
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