Gitiles
Code Review Sign In
gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / dc024674ff96820d6020757b48d47f46d4c07db2 / . / docs / LangRef.html
blob: f85a441e5317f7f1917bb0cf999001f42115407f [file] [log] [blame]
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
2 "http://www.w3.org/TR/html4/strict.dtd">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3<html>
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>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]29 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]30 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]31 </ol>
32 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]33 <li><a href="#typesystem">Type System</a>
34 <ol>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]35 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]36 <ol>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]37 <li><a href="#t_classifications">Type Classifications</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]38 </ol>
39 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]40 <li><a href="#t_derived">Derived Types</a>
41 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]42 <li><a href="#t_array">Array Type</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]43 <li><a href="#t_function">Function Type</a></li>
44 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]45 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]46 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]47 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]48 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]49 </ol>
50 </li>
51 </ol>
52 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]53 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]54 <ol>
55 <li><a href="#simpleconstants">Simple Constants</a>
56 <li><a href="#aggregateconstants">Aggregate Constants</a>
57 <li><a href="#globalconstants">Global Variable and Function Addresses</a>
58 <li><a href="#undefvalues">Undefined Values</a>
59 <li><a href="#constantexprs">Constant Expressions</a>
60 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]61 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]62 <li><a href="#othervalues">Other Values</a>
63 <ol>
64 <li><a href="#inlineasm">Inline Assembler Expressions</a>
65 </ol>
66 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]67 <li><a href="#instref">Instruction Reference</a>
68 <ol>
69 <li><a href="#terminators">Terminator Instructions</a>
70 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]71 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
72 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]73 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
74 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]75 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]76 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]77 </ol>
78 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]79 <li><a href="#binaryops">Binary Operations</a>
80 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]81 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
82 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
83 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]84 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
85 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
86 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]87 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
88 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
89 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]90 </ol>
91 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]92 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
93 <ol>
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]94 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
95 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
96 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]97 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]98 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]99 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]100 </ol>
101 </li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]102 <li><a href="#vectorops">Vector Operations</a>
103 <ol>
104 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
105 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
106 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]107 </ol>
108 </li>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]109 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]110 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]111 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
112 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
113 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]114 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
115 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
116 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]117 </ol>
118 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]119 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]120 <ol>
121 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
122 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
123 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
124 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
125 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]126 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
127 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
128 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
129 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]130 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
131 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]132 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]133 </ol>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]134 <li><a href="#otherops">Other Operations</a>
135 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]136 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
137 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]138 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]139 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]140 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]141 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]142 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]143 </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 Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]146 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]147 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]148 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
149 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]150 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
151 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
152 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]153 </ol>
154 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]155 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
156 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]157 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
158 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
159 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]160 </ol>
161 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]162 <li><a href="#int_codegen">Code Generator Intrinsics</a>
163 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]164 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
165 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
166 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
167 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
168 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
169 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
170 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]171 </ol>
172 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]173 <li><a href="#int_libc">Standard C Library Intrinsics</a>
174 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]175 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
176 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
177 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
178 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
179 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]180 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
181 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
182 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]183 </ol>
184 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]185 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]186 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]187 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]188 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
189 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
190 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]191 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
192 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]193 </ol>
194 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]195 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]196 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]197 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]198 <ol>
199 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]200 </ol>
201 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]202 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]203 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]204 <li><a href="#int_var_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]205 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]206 </ol>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]207 <ol>
208 <li><a href="#int_annotation">
Tanya Lattner91d0b882007-09-22 00:01:26 +0000[diff] [blame]209 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]210 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]211 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]212 </ol>
213 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]214</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]215
216<div class="doc_author">
217 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
218 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]219</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]220
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]221<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]222<div class="doc_section"> <a name="abstract">Abstract </a></div>
223<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]224
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]225<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]226<p>This document is a reference manual for the LLVM assembly language.
227LLVM is an SSA based representation that provides type safety,
228low-level operations, flexibility, and the capability of representing
229'all' high-level languages cleanly. It is the common code
230representation used throughout all phases of the LLVM compilation
231strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]232</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]233
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]234<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]235<div class="doc_section"> <a name="introduction">Introduction</a> </div>
236<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]237
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]238<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]239
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]240<p>The LLVM code representation is designed to be used in three
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]241different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]242representation (suitable for fast loading by a Just-In-Time compiler),
243and as a human readable assembly language representation. This allows
244LLVM to provide a powerful intermediate representation for efficient
245compiler transformations and analysis, while providing a natural means
246to debug and visualize the transformations. The three different forms
247of LLVM are all equivalent. This document describes the human readable
248representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]249
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]250<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]251while being expressive, typed, and extensible at the same time. It
252aims to be a "universal IR" of sorts, by being at a low enough level
253that high-level ideas may be cleanly mapped to it (similar to how
254microprocessors are "universal IR's", allowing many source languages to
255be mapped to them). By providing type information, LLVM can be used as
256the target of optimizations: for example, through pointer analysis, it
257can be proven that a C automatic variable is never accessed outside of
258the current function... allowing it to be promoted to a simple SSA
259value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]260
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]261</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]262
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]263<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]264<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]265
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]266<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]267
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]268<p>It is important to note that this document describes 'well formed'
269LLVM assembly language. There is a difference between what the parser
270accepts and what is considered 'well formed'. For example, the
271following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]272
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]273<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]274<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]275%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]276</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]277</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]278
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]279<p>...because the definition of <tt>%x</tt> does not dominate all of
280its uses. The LLVM infrastructure provides a verification pass that may
281be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]282automatically run by the parser after parsing input assembly and by
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]283the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]284by the verifier pass indicate bugs in transformation passes or input to
285the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]286</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]287
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]288<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]289
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]290<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]291<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]292<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]293
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]294<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]295
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]296 <p>LLVM identifiers come in two basic types: global and local. Global
297 identifiers (functions, global variables) begin with the @ character. Local
298 identifiers (register names, types) begin with the % character. Additionally,
299 there are three different formats for identifiers, for different purposes:
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]300
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]301<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]302 <li>Named values are represented as a string of characters with their prefix.
303 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
304 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]305 Identifiers which require other characters in their names can be surrounded
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]306 with quotes. In this way, anything except a <tt>&quot;</tt> character can
307 be used in a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]308
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]309 <li>Unnamed values are represented as an unsigned numeric value with their
310 prefix. For example, %12, @2, %44.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]311
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]312 <li>Constants, which are described in a <a href="#constants">section about
313 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]314</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]315
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]316<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]317don't need to worry about name clashes with reserved words, and the set of
318reserved words may be expanded in the future without penalty. Additionally,
319unnamed identifiers allow a compiler to quickly come up with a temporary
320variable without having to avoid symbol table conflicts.</p>
321
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]322<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]323languages. There are keywords for different opcodes
324('<tt><a href="#i_add">add</a></tt>',
325 '<tt><a href="#i_bitcast">bitcast</a></tt>',
326 '<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]327href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]328and others. These reserved words cannot conflict with variable names, because
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]329none of them start with a prefix character ('%' or '@').</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]330
331<p>Here is an example of LLVM code to multiply the integer variable
332'<tt>%X</tt>' by 8:</p>
333
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]334<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]335
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]336<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]337<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]338%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]339</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]340</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]341
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]342<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]343
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]344<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]345<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]346%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]347</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]348</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]349
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]350<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]351
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]352<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]353<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]354<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
355<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
356%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]357</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]358</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]359
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]360<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
361important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]362
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]363<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]364
365 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
366 line.</li>
367
368 <li>Unnamed temporaries are created when the result of a computation is not
369 assigned to a named value.</li>
370
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]371 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]372
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]373</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]374
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]375<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]376demonstrating instructions, we will follow an instruction with a comment that
377defines the type and name of value produced. Comments are shown in italic
378text.</p>
379
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]380</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]381
382<!-- *********************************************************************** -->
383<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
384<!-- *********************************************************************** -->
385
386<!-- ======================================================================= -->
387<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
388</div>
389
390<div class="doc_text">
391
392<p>LLVM programs are composed of "Module"s, each of which is a
393translation unit of the input programs. Each module consists of
394functions, global variables, and symbol table entries. Modules may be
395combined together with the LLVM linker, which merges function (and
396global variable) definitions, resolves forward declarations, and merges
397symbol table entries. Here is an example of the "hello world" module:</p>
398
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]399<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]400<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]401<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
402 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]403
404<i>; External declaration of the puts function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]405<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]406
407<i>; Definition of main function</i>
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]408define i32 @main() { <i>; i32()* </i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]409 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]410 %cast210 = <a
Chris Lattner6c0955b2007-06-12 17:01:15 +0000[diff] [blame]411 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]412
413 <i>; Call puts function to write out the string to stdout...</i>
414 <a
Chris Lattnera89e5f12007-06-12 17:00:26 +0000[diff] [blame]415 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]416 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]417 href="#i_ret">ret</a> i32 0<br>}<br>
418</pre>
419</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]420
421<p>This example is made up of a <a href="#globalvars">global variable</a>
422named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
423function, and a <a href="#functionstructure">function definition</a>
424for "<tt>main</tt>".</p>
425
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]426<p>In general, a module is made up of a list of global values,
427where both functions and global variables are global values. Global values are
428represented by a pointer to a memory location (in this case, a pointer to an
429array of char, and a pointer to a function), and have one of the following <a
430href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]431
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]432</div>
433
434<!-- ======================================================================= -->
435<div class="doc_subsection">
436 <a name="linkage">Linkage Types</a>
437</div>
438
439<div class="doc_text">
440
441<p>
442All Global Variables and Functions have one of the following types of linkage:
443</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]444
445<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]446
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]447 <dt><tt><b><a name="linkage_internal">internal</a></b></tt> </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]448
449 <dd>Global values with internal linkage are only directly accessible by
450 objects in the current module. In particular, linking code into a module with
451 an internal global value may cause the internal to be renamed as necessary to
452 avoid collisions. Because the symbol is internal to the module, all
453 references can be updated. This corresponds to the notion of the
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]454 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]455 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]456
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]457 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]458
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]459 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
460 the same name when linkage occurs. This is typically used to implement
461 inline functions, templates, or other code which must be generated in each
462 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
463 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]464 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]465
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]466 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]467
468 <dd>"<tt>weak</tt>" linkage is exactly the same as <tt>linkonce</tt> linkage,
469 except that unreferenced <tt>weak</tt> globals may not be discarded. This is
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]470 used for globals that may be emitted in multiple translation units, but that
471 are not guaranteed to be emitted into every translation unit that uses them.
472 One example of this are common globals in C, such as "<tt>int X;</tt>" at
473 global scope.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]474 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]475
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]476 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]477
478 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
479 pointer to array type. When two global variables with appending linkage are
480 linked together, the two global arrays are appended together. This is the
481 LLVM, typesafe, equivalent of having the system linker append together
482 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]483 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]484
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]485 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
486 <dd>The semantics of this linkage follow the ELF model: the symbol is weak
487 until linked, if not linked, the symbol becomes null instead of being an
488 undefined reference.
489 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]490
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]491 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]492
493 <dd>If none of the above identifiers are used, the global is externally
494 visible, meaning that it participates in linkage and can be used to resolve
495 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]496 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]497</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]498
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]499 <p>
500 The next two types of linkage are targeted for Microsoft Windows platform
501 only. They are designed to support importing (exporting) symbols from (to)
502 DLLs.
503 </p>
504
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]505 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]506 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
507
508 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
509 or variable via a global pointer to a pointer that is set up by the DLL
510 exporting the symbol. On Microsoft Windows targets, the pointer name is
511 formed by combining <code>_imp__</code> and the function or variable name.
512 </dd>
513
514 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
515
516 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
517 pointer to a pointer in a DLL, so that it can be referenced with the
518 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
519 name is formed by combining <code>_imp__</code> and the function or variable
520 name.
521 </dd>
522
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]523</dl>
524
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]525<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]526variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
527variable and was linked with this one, one of the two would be renamed,
528preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
529external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]530outside of the current module.</p>
531<p>It is illegal for a function <i>declaration</i>
532to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]533or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]534<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
535linkages.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]536</div>
537
538<!-- ======================================================================= -->
539<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]540 <a name="callingconv">Calling Conventions</a>
541</div>
542
543<div class="doc_text">
544
545<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
546and <a href="#i_invoke">invokes</a> can all have an optional calling convention
547specified for the call. The calling convention of any pair of dynamic
548caller/callee must match, or the behavior of the program is undefined. The
549following calling conventions are supported by LLVM, and more may be added in
550the future:</p>
551
552<dl>
553 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
554
555 <dd>This calling convention (the default if no other calling convention is
556 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]557 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]558 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]559 </dd>
560
561 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
562
563 <dd>This calling convention attempts to make calls as fast as possible
564 (e.g. by passing things in registers). This calling convention allows the
565 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner8cdc5bc2005-05-06 23:08:23 +0000[diff] [blame]566 without having to conform to an externally specified ABI. Implementations of
567 this convention should allow arbitrary tail call optimization to be supported.
568 This calling convention does not support varargs and requires the prototype of
569 all callees to exactly match the prototype of the function definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]570 </dd>
571
572 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
573
574 <dd>This calling convention attempts to make code in the caller as efficient
575 as possible under the assumption that the call is not commonly executed. As
576 such, these calls often preserve all registers so that the call does not break
577 any live ranges in the caller side. This calling convention does not support
578 varargs and requires the prototype of all callees to exactly match the
579 prototype of the function definition.
580 </dd>
581
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]582 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]583
584 <dd>Any calling convention may be specified by number, allowing
585 target-specific calling conventions to be used. Target specific calling
586 conventions start at 64.
587 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]588</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]589
590<p>More calling conventions can be added/defined on an as-needed basis, to
591support pascal conventions or any other well-known target-independent
592convention.</p>
593
594</div>
595
596<!-- ======================================================================= -->
597<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]598 <a name="visibility">Visibility Styles</a>
599</div>
600
601<div class="doc_text">
602
603<p>
604All Global Variables and Functions have one of the following visibility styles:
605</p>
606
607<dl>
608 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
609
610 <dd>On ELF, default visibility means that the declaration is visible to other
611 modules and, in shared libraries, means that the declared entity may be
612 overridden. On Darwin, default visibility means that the declaration is
613 visible to other modules. Default visibility corresponds to "external
614 linkage" in the language.
615 </dd>
616
617 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
618
619 <dd>Two declarations of an object with hidden visibility refer to the same
620 object if they are in the same shared object. Usually, hidden visibility
621 indicates that the symbol will not be placed into the dynamic symbol table,
622 so no other module (executable or shared library) can reference it
623 directly.
624 </dd>
625
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]626 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
627
628 <dd>On ELF, protected visibility indicates that the symbol will be placed in
629 the dynamic symbol table, but that references within the defining module will
630 bind to the local symbol. That is, the symbol cannot be overridden by another
631 module.
632 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]633</dl>
634
635</div>
636
637<!-- ======================================================================= -->
638<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]639 <a name="globalvars">Global Variables</a>
640</div>
641
642<div class="doc_text">
643
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]644<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]645instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]646an explicit section to be placed in, and may have an optional explicit alignment
647specified. A variable may be defined as "thread_local", which means that it
648will not be shared by threads (each thread will have a separated copy of the
649variable). A variable may be defined as a global "constant," which indicates
650that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]651optimization, allowing the global data to be placed in the read-only section of
652an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]653cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]654
655<p>
656LLVM explicitly allows <em>declarations</em> of global variables to be marked
657constant, even if the final definition of the global is not. This capability
658can be used to enable slightly better optimization of the program, but requires
659the language definition to guarantee that optimizations based on the
660'constantness' are valid for the translation units that do not include the
661definition.
662</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]663
664<p>As SSA values, global variables define pointer values that are in
665scope (i.e. they dominate) all basic blocks in the program. Global
666variables always define a pointer to their "content" type because they
667describe a region of memory, and all memory objects in LLVM are
668accessed through pointers.</p>
669
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]670<p>LLVM allows an explicit section to be specified for globals. If the target
671supports it, it will emit globals to the section specified.</p>
672
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]673<p>An explicit alignment may be specified for a global. If not present, or if
674the alignment is set to zero, the alignment of the global is set by the target
675to whatever it feels convenient. If an explicit alignment is specified, the
676global is forced to have at least that much alignment. All alignments must be
677a power of 2.</p>
678
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]679<p>For example, the following defines a global with an initializer, section,
680 and alignment:</p>
681
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]682<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]683<pre>
Chris Lattner3e63a9d2007-07-13 20:01:46 +0000[diff] [blame]684@G = constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]685</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]686</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]687
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]688</div>
689
690
691<!-- ======================================================================= -->
692<div class="doc_subsection">
693 <a name="functionstructure">Functions</a>
694</div>
695
696<div class="doc_text">
697
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]698<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
699an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]700<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]701<a href="#callingconv">calling convention</a>, a return type, an optional
702<a href="#paramattrs">parameter attribute</a> for the return type, a function
703name, a (possibly empty) argument list (each with optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]704<a href="#paramattrs">parameter attributes</a>), an optional section, an
705optional alignment, an opening curly brace, a list of basic blocks, and a
706closing curly brace.
707
708LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
709optional <a href="#linkage">linkage type</a>, an optional
710<a href="#visibility">visibility style</a>, an optional
711<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]712<a href="#paramattrs">parameter attribute</a> for the return type, a function
713name, a possibly empty list of arguments, and an optional alignment.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]714
715<p>A function definition contains a list of basic blocks, forming the CFG for
716the function. Each basic block may optionally start with a label (giving the
717basic block a symbol table entry), contains a list of instructions, and ends
718with a <a href="#terminators">terminator</a> instruction (such as a branch or
719function return).</p>
720
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]721<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]722executed on entrance to the function, and it is not allowed to have predecessor
723basic blocks (i.e. there can not be any branches to the entry block of a
724function). Because the block can have no predecessors, it also cannot have any
725<a href="#i_phi">PHI nodes</a>.</p>
726
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]727<p>LLVM allows an explicit section to be specified for functions. If the target
728supports it, it will emit functions to the section specified.</p>
729
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]730<p>An explicit alignment may be specified for a function. If not present, or if
731the alignment is set to zero, the alignment of the function is set by the target
732to whatever it feels convenient. If an explicit alignment is specified, the
733function is forced to have at least that much alignment. All alignments must be
734a power of 2.</p>
735
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]736</div>
737
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]738
739<!-- ======================================================================= -->
740<div class="doc_subsection">
741 <a name="aliasstructure">Aliases</a>
742</div>
743<div class="doc_text">
744 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikova80e1182007-04-28 13:45:00 +0000[diff] [blame]745 function or global variable or bitcast of global value). Aliases may have an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]746 optional <a href="#linkage">linkage type</a>, and an
747 optional <a href="#visibility">visibility style</a>.</p>
748
749 <h5>Syntax:</h5>
750
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]751<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]752<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]753@&lt;Name&gt; = [Linkage] [Visibility] alias &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]754</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]755</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]756
757</div>
758
759
760
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]761<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]762<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
763<div class="doc_text">
764 <p>The return type and each parameter of a function type may have a set of
765 <i>parameter attributes</i> associated with them. Parameter attributes are
766 used to communicate additional information about the result or parameters of
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame^]767 a function. Parameter attributes are considered to be part of the function,
768 not of the function type, so functions with different parameter attributes
769 can have the same function type.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]770
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]771 <p>Parameter attributes are simple keywords that follow the type specified. If
772 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]773 example:</p>
774
775<div class="doc_code">
776<pre>
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame^]777declare i32 @printf(i8* noalias , ...) nounwind
778declare i32 @atoi(i8*) nounwind readonly
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]779</pre>
780</div>
781
Duncan Sandsdc024672007-11-27 13:23:08 +0000[diff] [blame^]782 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
783 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]784
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]785 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]786 <dl>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]787 <dt><tt>zeroext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]788 <dd>This indicates that the parameter should be zero extended just before
789 a call to this function.</dd>
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]790 <dt><tt>signext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]791 <dd>This indicates that the parameter should be sign extended just before
792 a call to this function.</dd>
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]793 <dt><tt>inreg</tt></dt>
794 <dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000[diff] [blame]795 possible) during assembling function call. Support for this attribute is
796 target-specific</dd>
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]797 <dt><tt>sret</tt></dt>
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000[diff] [blame]798 <dd>This indicates that the parameter specifies the address of a structure
Reid Spencer67606122007-03-22 02:02:11 +0000[diff] [blame]799 that is the return value of the function in the source program.</dd>
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]800 <dt><tt>noalias</tt></dt>
801 <dd>This indicates that the parameter not alias any other object or any
802 other "noalias" objects during the function call.
Reid Spencer2dc52012007-03-22 02:18:56 +0000[diff] [blame]803 <dt><tt>noreturn</tt></dt>
804 <dd>This function attribute indicates that the function never returns. This
805 indicates to LLVM that every call to this function should be treated as if
806 an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Reid Spencer67606122007-03-22 02:02:11 +0000[diff] [blame]807 <dt><tt>nounwind</tt></dt>
808 <dd>This function attribute indicates that the function type does not use
809 the unwind instruction and does not allow stack unwinding to propagate
810 through it.</dd>
Duncan Sands50f19f52007-07-27 19:57:41 +0000[diff] [blame]811 <dt><tt>nest</tt></dt>
812 <dd>This indicates that the parameter can be excised using the
813 <a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sandsed4a2f12007-11-22 20:23:04 +0000[diff] [blame]814 <dt><tt>readonly</tt></dt>
Duncan Sandsf04d5842007-11-14 21:14:02 +0000[diff] [blame]815 <dd>This function attribute indicates that the function has no side-effects
Duncan Sandsed4a2f12007-11-22 20:23:04 +0000[diff] [blame]816 except for producing a return value or throwing an exception. The value
817 returned must only depend on the function arguments and/or global variables.
818 It may use values obtained by dereferencing pointers.</dd>
819 <dt><tt>readnone</tt></dt>
820 <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]821 function, but in addition it is not allowed to dereference any pointer arguments
822 or global variables.
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]823 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]824
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]825</div>
826
827<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]828<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]829 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]830</div>
831
832<div class="doc_text">
833<p>
834Modules may contain "module-level inline asm" blocks, which corresponds to the
835GCC "file scope inline asm" blocks. These blocks are internally concatenated by
836LLVM and treated as a single unit, but may be separated in the .ll file if
837desired. The syntax is very simple:
838</p>
839
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]840<div class="doc_code">
841<pre>
842module asm "inline asm code goes here"
843module asm "more can go here"
844</pre>
845</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]846
847<p>The strings can contain any character by escaping non-printable characters.
848 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
849 for the number.
850</p>
851
852<p>
853 The inline asm code is simply printed to the machine code .s file when
854 assembly code is generated.
855</p>
856</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]857
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]858<!-- ======================================================================= -->
859<div class="doc_subsection">
860 <a name="datalayout">Data Layout</a>
861</div>
862
863<div class="doc_text">
864<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]865data is to be laid out in memory. The syntax for the data layout is simply:</p>
866<pre> target datalayout = "<i>layout specification</i>"</pre>
867<p>The <i>layout specification</i> consists of a list of specifications
868separated by the minus sign character ('-'). Each specification starts with a
869letter and may include other information after the letter to define some
870aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]871<dl>
872 <dt><tt>E</tt></dt>
873 <dd>Specifies that the target lays out data in big-endian form. That is, the
874 bits with the most significance have the lowest address location.</dd>
875 <dt><tt>e</tt></dt>
876 <dd>Specifies that hte target lays out data in little-endian form. That is,
877 the bits with the least significance have the lowest address location.</dd>
878 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
879 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
880 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
881 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
882 too.</dd>
883 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
884 <dd>This specifies the alignment for an integer type of a given bit
885 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
886 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
887 <dd>This specifies the alignment for a vector type of a given bit
888 <i>size</i>.</dd>
889 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
890 <dd>This specifies the alignment for a floating point type of a given bit
891 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
892 (double).</dd>
893 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
894 <dd>This specifies the alignment for an aggregate type of a given bit
895 <i>size</i>.</dd>
896</dl>
897<p>When constructing the data layout for a given target, LLVM starts with a
898default set of specifications which are then (possibly) overriden by the
899specifications in the <tt>datalayout</tt> keyword. The default specifications
900are given in this list:</p>
901<ul>
902 <li><tt>E</tt> - big endian</li>
903 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
904 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
905 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
906 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
907 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
908 <li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
909 alignment of 64-bits</li>
910 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
911 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
912 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
913 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
914 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
915</ul>
916<p>When llvm is determining the alignment for a given type, it uses the
917following rules:
918<ol>
919 <li>If the type sought is an exact match for one of the specifications, that
920 specification is used.</li>
921 <li>If no match is found, and the type sought is an integer type, then the
922 smallest integer type that is larger than the bitwidth of the sought type is
923 used. If none of the specifications are larger than the bitwidth then the the
924 largest integer type is used. For example, given the default specifications
925 above, the i7 type will use the alignment of i8 (next largest) while both
926 i65 and i256 will use the alignment of i64 (largest specified).</li>
927 <li>If no match is found, and the type sought is a vector type, then the
928 largest vector type that is smaller than the sought vector type will be used
929 as a fall back. This happens because <128 x double> can be implemented in
930 terms of 64 <2 x double>, for example.</li>
931</ol>
932</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]933
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]934<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]935<div class="doc_section"> <a name="typesystem">Type System</a> </div>
936<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]937
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]938<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]939
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]940<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]941intermediate representation. Being typed enables a number of
942optimizations to be performed on the IR directly, without having to do
943extra analyses on the side before the transformation. A strong type
944system makes it easier to read the generated code and enables novel
945analyses and transformations that are not feasible to perform on normal
946three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]947
948</div>
949
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]950<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]951<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]952<div class="doc_text">
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]953<p>The primitive types are the fundamental building blocks of the LLVM
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]954system. The current set of primitive types is as follows:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]955
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]956<table class="layout">
957 <tr class="layout">
958 <td class="left">
959 <table>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]960 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]961 <tr><th>Type</th><th>Description</th></tr>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]962 <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]963 <tr><td><tt>label</tt></td><td>Branch destination</td></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]964 </tbody>
965 </table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]966 </td>
967 <td class="right">
968 <table>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]969 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]970 <tr><th>Type</th><th>Description</th></tr>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]971 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]972 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]973 </tbody>
974 </table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]975 </td>
976 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]977</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]978</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]979
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]980<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]981<div class="doc_subsubsection"> <a name="t_classifications">Type
982Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]983<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]984<p>These different primitive types fall into a few useful
985classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]986
987<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]988 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]989 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]990 <tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]991 <td><a name="t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]992 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]993 </tr>
994 <tr>
995 <td><a name="t_floating">floating point</a></td>
996 <td><tt>float, double</tt></td>
997 </tr>
998 <tr>
999 <td><a name="t_firstclass">first class</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1000 <td><tt>i1, ..., float, double, <br/>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1001 <a href="#t_pointer">pointer</a>,<a href="#t_vector">vector</a></tt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1002 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1003 </tr>
1004 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1005</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1006
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1007<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1008most important. Values of these types are the only ones which can be
1009produced by instructions, passed as arguments, or used as operands to
1010instructions. This means that all structures and arrays must be
1011manipulated either by pointer or by component.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1012</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1013
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1014<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1015<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1016
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1017<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1018
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1019<p>The real power in LLVM comes from the derived types in the system.
1020This is what allows a programmer to represent arrays, functions,
1021pointers, and other useful types. Note that these derived types may be
1022recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1023
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1024</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1025
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1026<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1027<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1028
1029<div class="doc_text">
1030
1031<h5>Overview:</h5>
1032<p>The integer type is a very simple derived type that simply specifies an
1033arbitrary bit width for the integer type desired. Any bit width from 1 bit to
10342^23-1 (about 8 million) can be specified.</p>
1035
1036<h5>Syntax:</h5>
1037
1038<pre>
1039 iN
1040</pre>
1041
1042<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1043value.</p>
1044
1045<h5>Examples:</h5>
1046<table class="layout">
1047 <tr class="layout">
1048 <td class="left">
1049 <tt>i1</tt><br/>
1050 <tt>i4</tt><br/>
1051 <tt>i8</tt><br/>
1052 <tt>i16</tt><br/>
1053 <tt>i32</tt><br/>
1054 <tt>i42</tt><br/>
1055 <tt>i64</tt><br/>
1056 <tt>i1942652</tt><br/>
1057 </td>
1058 <td class="left">
1059 A boolean integer of 1 bit<br/>
1060 A nibble sized integer of 4 bits.<br/>
1061 A byte sized integer of 8 bits.<br/>
1062 A half word sized integer of 16 bits.<br/>
1063 A word sized integer of 32 bits.<br/>
1064 An integer whose bit width is the answer. <br/>
1065 A double word sized integer of 64 bits.<br/>
1066 A really big integer of over 1 million bits.<br/>
1067 </td>
1068 </tr>
1069</table>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1070</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1071
1072<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1073<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1074
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1075<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1076
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1077<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1078
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1079<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1080sequentially in memory. The array type requires a size (number of
1081elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1082
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1083<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1084
1085<pre>
1086 [&lt;# elements&gt; x &lt;elementtype&gt;]
1087</pre>
1088
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1089<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1090be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1091
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1092<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1093<table class="layout">
1094 <tr class="layout">
1095 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1096 <tt>[40 x i32 ]</tt><br/>
1097 <tt>[41 x i32 ]</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1098 <tt>[40 x i8]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1099 </td>
1100 <td class="left">
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1101 Array of 40 32-bit integer values.<br/>
1102 Array of 41 32-bit integer values.<br/>
1103 Array of 40 8-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1104 </td>
1105 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1106</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1107<p>Here are some examples of multidimensional arrays:</p>
1108<table class="layout">
1109 <tr class="layout">
1110 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1111 <tt>[3 x [4 x i32]]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1112 <tt>[12 x [10 x float]]</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1113 <tt>[2 x [3 x [4 x i16]]]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1114 </td>
1115 <td class="left">
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1116 3x4 array of 32-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1117 12x10 array of single precision floating point values.<br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1118 2x3x4 array of 16-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1119 </td>
1120 </tr>
1121</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1122
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1123<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1124length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1125LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1126As a special case, however, zero length arrays are recognized to be variable
1127length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1128type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1129
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1130</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1131
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1132<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1133<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1134<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1135<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1136<p>The function type can be thought of as a function signature. It
1137consists of a return type and a list of formal parameter types.
John Criswell009900b2003-11-25 21:45:46 +0000[diff] [blame]1138Function types are usually used to build virtual function tables
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1139(which are structures of pointers to functions), for indirect function
1140calls, and when defining a function.</p>
John Criswell009900b2003-11-25 21:45:46 +0000[diff] [blame]1141<p>
1142The return type of a function type cannot be an aggregate type.
1143</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1144<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1145<pre> &lt;returntype&gt; (&lt;parameter list&gt;)<br></pre>
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1146<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]1147specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1148which indicates that the function takes a variable number of arguments.
1149Variable argument functions can access their arguments with the <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1150 href="#int_varargs">variable argument handling intrinsic</a> functions.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1151<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1152<table class="layout">
1153 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1154 <td class="left"><tt>i32 (i32)</tt></td>
1155 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1156 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1157 </tr><tr class="layout">
Reid Spencer9445e9a2007-07-19 23:13:04 +0000[diff] [blame]1158 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1159 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1160 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1161 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1162 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1163 <tt>float</tt>.
1164 </td>
1165 </tr><tr class="layout">
1166 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1167 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1168 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1169 which returns an integer. This is the signature for <tt>printf</tt> in
1170 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1171 </td>
1172 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1173</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1174
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1175</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1176<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1177<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1178<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1179<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1180<p>The structure type is used to represent a collection of data members
1181together in memory. The packing of the field types is defined to match
1182the ABI of the underlying processor. The elements of a structure may
1183be any type that has a size.</p>
1184<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1185and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1186field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1187instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1188<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1189<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1190<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1191<table class="layout">
1192 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1193 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1194 <td class="left">A triple of three <tt>i32</tt> values</td>
1195 </tr><tr class="layout">
1196 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1197 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1198 second element is a <a href="#t_pointer">pointer</a> to a
1199 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1200 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1201 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1202</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1203</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1204
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1205<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1206<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1207</div>
1208<div class="doc_text">
1209<h5>Overview:</h5>
1210<p>The packed structure type is used to represent a collection of data members
1211together in memory. There is no padding between fields. Further, the alignment
1212of a packed structure is 1 byte. The elements of a packed structure may
1213be any type that has a size.</p>
1214<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1215and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1216field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1217instruction.</p>
1218<h5>Syntax:</h5>
1219<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1220<h5>Examples:</h5>
1221<table class="layout">
1222 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1223 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1224 <td class="left">A triple of three <tt>i32</tt> values</td>
1225 </tr><tr class="layout">
1226 <td class="left"><tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}&nbsp;&gt;</tt></td>
1227 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1228 second element is a <a href="#t_pointer">pointer</a> to a
1229 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1230 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1231 </tr>
1232</table>
1233</div>
1234
1235<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1236<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1237<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1238<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1239<p>As in many languages, the pointer type represents a pointer or
1240reference to another object, which must live in memory.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1241<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1242<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1243<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1244<table class="layout">
1245 <tr class="layout">
1246 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1247 <tt>[4x i32]*</tt><br/>
1248 <tt>i32 (i32 *) *</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1249 </td>
1250 <td class="left">
1251 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]1252 four <tt>i32</tt> values<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1253 A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1254 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
1255 <tt>i32</tt>.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1256 </td>
1257 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1258</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1259</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1260
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1261<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1262<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1263<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1264
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1265<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1266
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1267<p>A vector type is a simple derived type that represents a vector
1268of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1269are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1270A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1271elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1272of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1273considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1274
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1275<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1276
1277<pre>
1278 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1279</pre>
1280
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1281<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1282be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1283
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1284<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1285
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1286<table class="layout">
1287 <tr class="layout">
1288 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1289 <tt>&lt;4 x i32&gt;</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1290 <tt>&lt;8 x float&gt;</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1291 <tt>&lt;2 x i64&gt;</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1292 </td>
1293 <td class="left">
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1294 Vector of 4 32-bit integer values.<br/>
1295 Vector of 8 floating-point values.<br/>
1296 Vector of 2 64-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1297 </td>
1298 </tr>
1299</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1300</div>
1301
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1302<!-- _______________________________________________________________________ -->
1303<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1304<div class="doc_text">
1305
1306<h5>Overview:</h5>
1307
1308<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen8ac04ff2007-10-14 00:34:53 +0000[diff] [blame]1309corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1310In LLVM, opaque types can eventually be resolved to any type (not just a
1311structure type).</p>
1312
1313<h5>Syntax:</h5>
1314
1315<pre>
1316 opaque
1317</pre>
1318
1319<h5>Examples:</h5>
1320
1321<table class="layout">
1322 <tr class="layout">
1323 <td class="left">
1324 <tt>opaque</tt>
1325 </td>
1326 <td class="left">
1327 An opaque type.<br/>
1328 </td>
1329 </tr>
1330</table>
1331</div>
1332
1333
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1334<!-- *********************************************************************** -->
1335<div class="doc_section"> <a name="constants">Constants</a> </div>
1336<!-- *********************************************************************** -->
1337
1338<div class="doc_text">
1339
1340<p>LLVM has several different basic types of constants. This section describes
1341them all and their syntax.</p>
1342
1343</div>
1344
1345<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1346<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1347
1348<div class="doc_text">
1349
1350<dl>
1351 <dt><b>Boolean constants</b></dt>
1352
1353 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1354 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1355 </dd>
1356
1357 <dt><b>Integer constants</b></dt>
1358
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1359 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1360 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1361 integer types.
1362 </dd>
1363
1364 <dt><b>Floating point constants</b></dt>
1365
1366 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1367 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1368 notation (see below). Floating point constants must have a <a
1369 href="#t_floating">floating point</a> type. </dd>
1370
1371 <dt><b>Null pointer constants</b></dt>
1372
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1373 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1374 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1375
1376</dl>
1377
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1378<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1379of floating point constants. For example, the form '<tt>double
13800x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
13814.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1382(and the only time that they are generated by the disassembler) is when a
1383floating point constant must be emitted but it cannot be represented as a
1384decimal floating point number. For example, NaN's, infinities, and other
1385special values are represented in their IEEE hexadecimal format so that
1386assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1387
1388</div>
1389
1390<!-- ======================================================================= -->
1391<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1392</div>
1393
1394<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1395<p>Aggregate constants arise from aggregation of simple constants
1396and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1397
1398<dl>
1399 <dt><b>Structure constants</b></dt>
1400
1401 <dd>Structure constants are represented with notation similar to structure
1402 type definitions (a comma separated list of elements, surrounded by braces
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1403 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* %G }</tt>",
Chris Lattner3e63a9d2007-07-13 20:01:46 +0000[diff] [blame]1404 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]1405 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1406 types of elements must match those specified by the type.
1407 </dd>
1408
1409 <dt><b>Array constants</b></dt>
1410
1411 <dd>Array constants are represented with notation similar to array type
1412 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1413 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1414 constants must have <a href="#t_array">array type</a>, and the number and
1415 types of elements must match those specified by the type.
1416 </dd>
1417
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1418 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1419
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1420 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1421 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1422 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]1423 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1424 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1425 match those specified by the type.
1426 </dd>
1427
1428 <dt><b>Zero initialization</b></dt>
1429
1430 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1431 value to zero of <em>any</em> type, including scalar and aggregate types.
1432 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]1433 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1434 initializers.
1435 </dd>
1436</dl>
1437
1438</div>
1439
1440<!-- ======================================================================= -->
1441<div class="doc_subsection">
1442 <a name="globalconstants">Global Variable and Function Addresses</a>
1443</div>
1444
1445<div class="doc_text">
1446
1447<p>The addresses of <a href="#globalvars">global variables</a> and <a
1448href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1449constants. These constants are explicitly referenced when the <a
1450href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1451href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1452file:</p>
1453
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1454<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1455<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1456@X = global i32 17
1457@Y = global i32 42
1458@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1459</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1460</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1461
1462</div>
1463
1464<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1465<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1466<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1467 <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]1468 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1469 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1470
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1471 <p>Undefined values indicate to the compiler that the program is well defined
1472 no matter what value is used, giving the compiler more freedom to optimize.
1473 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1474</div>
1475
1476<!-- ======================================================================= -->
1477<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1478</div>
1479
1480<div class="doc_text">
1481
1482<p>Constant expressions are used to allow expressions involving other constants
1483to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1484href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1485that does not have side effects (e.g. load and call are not supported). The
1486following is the syntax for constant expressions:</p>
1487
1488<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1489 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1490 <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]1491 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1492
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1493 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1494 <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]1495 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]1496
1497 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1498 <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]1499 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]1500
1501 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1502 <dd>Truncate a floating point constant to another floating point type. The
1503 size of CST must be larger than the size of TYPE. Both types must be
1504 floating point.</dd>
1505
1506 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1507 <dd>Floating point extend a constant to another type. The size of CST must be
1508 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1509
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]1510 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1511 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1512 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1513 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1514 of the same number of elements. If the value won't fit in the integer type,
1515 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1516
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1517 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1518 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1519 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1520 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1521 of the same number of elements. If the value won't fit in the integer type,
1522 the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1523
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1524 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1525 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1526 constant. TYPE must be a scalar or vector floating point type. CST must be of
1527 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1528 of the same number of elements. If the value won't fit in the floating point
1529 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1530
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1531 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1532 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]1533 constant. TYPE must be a scalar or vector floating point type. CST must be of
1534 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1535 of the same number of elements. If the value won't fit in the floating point
1536 type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1537
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1538 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1539 <dd>Convert a pointer typed constant to the corresponding integer constant
1540 TYPE must be an integer type. CST must be of pointer type. The CST value is
1541 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1542
1543 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1544 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1545 pointer type. CST must be of integer type. The CST value is zero extended,
1546 truncated, or unchanged to make it fit in a pointer size. This one is
1547 <i>really</i> dangerous!</dd>
1548
1549 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1550 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1551 identical (same number of bits). The conversion is done as if the CST value
1552 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]1553 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1554 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]1555 pointers it is only valid to cast to another pointer type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1556 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1557
1558 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1559
1560 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1561 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1562 instruction, the index list may have zero or more indexes, which are required
1563 to make sense for the type of "CSTPTR".</dd>
1564
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1565 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1566
1567 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1568 constants.</dd>
1569
1570 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1571 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1572
1573 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1574 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1575
1576 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1577
1578 <dd>Perform the <a href="#i_extractelement">extractelement
1579 operation</a> on constants.
1580
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1581 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1582
1583 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1584 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1585
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1586
1587 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1588
1589 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1590 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1591
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1592 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1593
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1594 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1595 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1596 binary</a> operations. The constraints on operands are the same as those for
1597 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1598 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1599</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1600</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1601
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1602<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1603<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1604<!-- *********************************************************************** -->
1605
1606<!-- ======================================================================= -->
1607<div class="doc_subsection">
1608<a name="inlineasm">Inline Assembler Expressions</a>
1609</div>
1610
1611<div class="doc_text">
1612
1613<p>
1614LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1615Module-Level Inline Assembly</a>) through the use of a special value. This
1616value represents the inline assembler as a string (containing the instructions
1617to emit), a list of operand constraints (stored as a string), and a flag that
1618indicates whether or not the inline asm expression has side effects. An example
1619inline assembler expression is:
1620</p>
1621
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1622<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1623<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1624i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1625</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1626</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1627
1628<p>
1629Inline assembler expressions may <b>only</b> be used as the callee operand of
1630a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1631</p>
1632
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1633<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1634<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1635%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]1636</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1637</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1638
1639<p>
1640Inline asms with side effects not visible in the constraint list must be marked
1641as having side effects. This is done through the use of the
1642'<tt>sideeffect</tt>' keyword, like so:
1643</p>
1644
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1645<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1646<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1647call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1648</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1649</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1650
1651<p>TODO: The format of the asm and constraints string still need to be
1652documented here. Constraints on what can be done (e.g. duplication, moving, etc
1653need to be documented).
1654</p>
1655
1656</div>
1657
1658<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1659<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1660<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1661
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1662<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1663
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1664<p>The LLVM instruction set consists of several different
1665classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1666instructions</a>, <a href="#binaryops">binary instructions</a>,
1667<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1668 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1669instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1670
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1671</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1672
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1673<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1674<div class="doc_subsection"> <a name="terminators">Terminator
1675Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1676
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1677<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1678
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1679<p>As mentioned <a href="#functionstructure">previously</a>, every
1680basic block in a program ends with a "Terminator" instruction, which
1681indicates which block should be executed after the current block is
1682finished. These terminator instructions typically yield a '<tt>void</tt>'
1683value: they produce control flow, not values (the one exception being
1684the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1685<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1686 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1687instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1688the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1689 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1690 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1691
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1692</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1693
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1694<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1695<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1696Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1697<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1698<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1699<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]1700 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1701</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1702<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1703<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1704value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]1705<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1706returns a value and then causes control flow, and one that just causes
1707control flow to occur.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1708<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1709<p>The '<tt>ret</tt>' instruction may return any '<a
1710 href="#t_firstclass">first class</a>' type. Notice that a function is
1711not <a href="#wellformed">well formed</a> if there exists a '<tt>ret</tt>'
1712instruction inside of the function that returns a value that does not
1713match the return type of the function.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1714<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1715<p>When the '<tt>ret</tt>' instruction is executed, control flow
1716returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]1717 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1718the instruction after the call. If the caller was an "<a
1719 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1720at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1721returns a value, that value shall set the call or invoke instruction's
1722return value.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1723<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1724<pre> ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1725 ret void <i>; Return from a void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1726</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1727</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1728<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1729<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1730<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1731<h5>Syntax:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1732<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]1733</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1734<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1735<p>The '<tt>br</tt>' instruction is used to cause control flow to
1736transfer to a different basic block in the current function. There are
1737two forms of this instruction, corresponding to a conditional branch
1738and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1739<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1740<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1741single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1742unconditional form of the '<tt>br</tt>' instruction takes a single
1743'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1744<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1745<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1746argument is evaluated. If the value is <tt>true</tt>, control flows
1747to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1748control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1749<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1750<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]1751 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]1752</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1753<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1754<div class="doc_subsubsection">
1755 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1756</div>
1757
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1758<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1759<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1760
1761<pre>
1762 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1763</pre>
1764
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1765<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1766
1767<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1768several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1769instruction, allowing a branch to occur to one of many possible
1770destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1771
1772
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1773<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1774
1775<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1776comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1777an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1778table is not allowed to contain duplicate constant entries.</p>
1779
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1780<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1781
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1782<p>The <tt>switch</tt> instruction specifies a table of values and
1783destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1784table is searched for the given value. If the value is found, control flow is
1785transfered to the corresponding destination; otherwise, control flow is
1786transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1787
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1788<h5>Implementation:</h5>
1789
1790<p>Depending on properties of the target machine and the particular
1791<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1792ways. For example, it could be generated as a series of chained conditional
1793branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1794
1795<h5>Example:</h5>
1796
1797<pre>
1798 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1799 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1800 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1801
1802 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1803 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1804
1805 <i>; Implement a jump table:</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1806 switch i32 %val, label %otherwise [ i32 0, label %onzero
1807 i32 1, label %onone
1808 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1809</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1810</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1811
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1812<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1813<div class="doc_subsubsection">
1814 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
1815</div>
1816
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1817<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1818
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1819<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1820
1821<pre>
1822 &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]1823 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1824</pre>
1825
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]1826<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1827
1828<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
1829function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1830'<tt>normal</tt>' label or the
1831'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1832"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
1833"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1834href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
1835continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1836
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1837<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1838
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1839<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1840
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1841<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1842 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]1843 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1844 convention</a> the call should use. If none is specified, the call defaults
1845 to using C calling conventions.
1846 </li>
1847 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
1848 function value being invoked. In most cases, this is a direct function
1849 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
1850 an arbitrary pointer to function value.
1851 </li>
1852
1853 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
1854 function to be invoked. </li>
1855
1856 <li>'<tt>function args</tt>': argument list whose types match the function
1857 signature argument types. If the function signature indicates the function
1858 accepts a variable number of arguments, the extra arguments can be
1859 specified. </li>
1860
1861 <li>'<tt>normal label</tt>': the label reached when the called function
1862 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
1863
1864 <li>'<tt>exception label</tt>': the label reached when a callee returns with
1865 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
1866
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1867</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1868
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1869<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1870
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1871<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1872href="#i_call">call</a></tt>' instruction in most regards. The primary
1873difference is that it establishes an association with a label, which is used by
1874the runtime library to unwind the stack.</p>
1875
1876<p>This instruction is used in languages with destructors to ensure that proper
1877cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
1878exception. Additionally, this is important for implementation of
1879'<tt>catch</tt>' clauses in high-level languages that support them.</p>
1880
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1881<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1882<pre>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1883 %retval = invoke i32 %Test(i32 15) to label %Continue
1884 unwind label %TestCleanup <i>; {i32}:retval set</i>
1885 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Test(i32 15) to label %Continue
1886 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1887</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1888</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1889
1890
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1891<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1892
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1893<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
1894Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1895
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1896<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1897
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1898<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1899<pre>
1900 unwind
1901</pre>
1902
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1903<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1904
1905<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
1906at the first callee in the dynamic call stack which used an <a
1907href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
1908primarily used to implement exception handling.</p>
1909
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1910<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1911
1912<p>The '<tt>unwind</tt>' intrinsic causes execution of the current function to
1913immediately halt. The dynamic call stack is then searched for the first <a
1914href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
1915execution continues at the "exceptional" destination block specified by the
1916<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
1917dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1918</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1919
1920<!-- _______________________________________________________________________ -->
1921
1922<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
1923Instruction</a> </div>
1924
1925<div class="doc_text">
1926
1927<h5>Syntax:</h5>
1928<pre>
1929 unreachable
1930</pre>
1931
1932<h5>Overview:</h5>
1933
1934<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
1935instruction is used to inform the optimizer that a particular portion of the
1936code is not reachable. This can be used to indicate that the code after a
1937no-return function cannot be reached, and other facts.</p>
1938
1939<h5>Semantics:</h5>
1940
1941<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
1942</div>
1943
1944
1945
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1946<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1947<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1948<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1949<p>Binary operators are used to do most of the computation in a
1950program. They require two operands, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1951produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1952multiple 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]1953The result value of a binary operator is not
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1954necessarily the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1955<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1956</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1957<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1958<div class="doc_subsubsection"> <a name="i_add">'<tt>add</tt>'
1959Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1960<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1961<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1962<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]1963</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1964<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1965<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1966<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1967<p>The two arguments to the '<tt>add</tt>' instruction must be either <a
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1968 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a> values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1969 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]1970Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1971<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1972<p>The value produced is the integer or floating point sum of the two
1973operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1974<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1975<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]1976</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1977</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1978<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1979<div class="doc_subsubsection"> <a name="i_sub">'<tt>sub</tt>'
1980Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1981<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1982<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1983<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]1984</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1985<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1986<p>The '<tt>sub</tt>' instruction returns the difference of its two
1987operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1988<p>Note that the '<tt>sub</tt>' instruction is used to represent the '<tt>neg</tt>'
1989instruction present in most other intermediate representations.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1990<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1991<p>The two arguments to the '<tt>sub</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1992 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1993values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1994This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1995Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1996<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1997<p>The value produced is the integer or floating point difference of
1998the two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1999<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2000<pre>
2001 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2002 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2003</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2004</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2005<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2006<div class="doc_subsubsection"> <a name="i_mul">'<tt>mul</tt>'
2007Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2008<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2009<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2010<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]2011</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2012<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2013<p>The '<tt>mul</tt>' instruction returns the product of its two
2014operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2015<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2016<p>The two arguments to the '<tt>mul</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2017 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2018values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2019This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2020Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2021<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2022<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2023two operands.</p>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]2024<p>Because the operands are the same width, the result of an integer
2025multiplication is the same whether the operands should be deemed unsigned or
2026signed.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2027<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2028<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]2029</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2030</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2031<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2032<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2033</a></div>
2034<div class="doc_text">
2035<h5>Syntax:</h5>
2036<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2037</pre>
2038<h5>Overview:</h5>
2039<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2040operands.</p>
2041<h5>Arguments:</h5>
2042<p>The two arguments to the '<tt>udiv</tt>' instruction must be
2043<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2044types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2045of the values in which case the elements must be integers.</p>
2046<h5>Semantics:</h5>
2047<p>The value produced is the unsigned integer quotient of the two operands. This
2048instruction always performs an unsigned division operation, regardless of
2049whether the arguments are unsigned or not.</p>
2050<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2051<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]2052</pre>
2053</div>
2054<!-- _______________________________________________________________________ -->
2055<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2056</a> </div>
2057<div class="doc_text">
2058<h5>Syntax:</h5>
2059<pre> &lt;result&gt; = sdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2060</pre>
2061<h5>Overview:</h5>
2062<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2063operands.</p>
2064<h5>Arguments:</h5>
2065<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2066<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2067types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2068of the values in which case the elements must be integers.</p>
2069<h5>Semantics:</h5>
2070<p>The value produced is the signed integer quotient of the two operands. This
2071instruction always performs a signed division operation, regardless of whether
2072the arguments are signed or not.</p>
2073<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2074<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]2075</pre>
2076</div>
2077<!-- _______________________________________________________________________ -->
2078<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2079Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2080<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2081<h5>Syntax:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2082<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]2083</pre>
2084<h5>Overview:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2085<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2086operands.</p>
2087<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2088<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2089<a href="#t_floating">floating point</a> values. Both arguments must have
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2090identical types. This instruction can also take <a href="#t_vector">vector</a>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2091versions of floating point values.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2092<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2093<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2094<h5>Example:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2095<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]2096</pre>
2097</div>
2098<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2099<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2100</div>
2101<div class="doc_text">
2102<h5>Syntax:</h5>
2103<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2104</pre>
2105<h5>Overview:</h5>
2106<p>The '<tt>urem</tt>' instruction returns the remainder from the
2107unsigned division of its two arguments.</p>
2108<h5>Arguments:</h5>
2109<p>The two arguments to the '<tt>urem</tt>' instruction must be
2110<a href="#t_integer">integer</a> values. Both arguments must have identical
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2111types. This instruction can also take <a href="#t_vector">vector</a> versions
2112of the values in which case the elements must be integers.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2113<h5>Semantics:</h5>
2114<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
2115This instruction always performs an unsigned division to get the remainder,
2116regardless of whether the arguments are unsigned or not.</p>
2117<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2118<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]2119</pre>
2120
2121</div>
2122<!-- _______________________________________________________________________ -->
2123<div class="doc_subsubsection"> <a name="i_srem">'<tt>srem</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2124Instruction</a> </div>
2125<div class="doc_text">
2126<h5>Syntax:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2127<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]2128</pre>
2129<h5>Overview:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2130<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2131signed division of its two operands. This instruction can also take
2132<a href="#t_vector">vector</a> versions of the values in which case
2133the elements must be integers.</p>
2134</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2135<h5>Arguments:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2136<p>The two arguments to the '<tt>srem</tt>' instruction must be
2137<a href="#t_integer">integer</a> values. Both arguments must have identical
2138types.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2139<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2140<p>This instruction returns the <i>remainder</i> of a division (where the result
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2141has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
2142operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
2143a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2144 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2145Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2146please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2147Wikipedia: modulo operation</a>.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2148<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2149<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]2150</pre>
2151
2152</div>
2153<!-- _______________________________________________________________________ -->
2154<div class="doc_subsubsection"> <a name="i_frem">'<tt>frem</tt>'
2155Instruction</a> </div>
2156<div class="doc_text">
2157<h5>Syntax:</h5>
2158<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2159</pre>
2160<h5>Overview:</h5>
2161<p>The '<tt>frem</tt>' instruction returns the remainder from the
2162division of its two operands.</p>
2163<h5>Arguments:</h5>
2164<p>The two arguments to the '<tt>frem</tt>' instruction must be
2165<a href="#t_floating">floating point</a> values. Both arguments must have
Dan Gohman80176312007-11-05 23:35:22 +0000[diff] [blame]2166identical types. This instruction can also take <a href="#t_vector">vector</a>
2167versions of floating point values.</p>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2168<h5>Semantics:</h5>
2169<p>This instruction returns the <i>remainder</i> of a division.</p>
2170<h5>Example:</h5>
2171<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]2172</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2173</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2174
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2175<!-- ======================================================================= -->
2176<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2177Operations</a> </div>
2178<div class="doc_text">
2179<p>Bitwise binary operators are used to do various forms of
2180bit-twiddling in a program. They are generally very efficient
2181instructions and can commonly be strength reduced from other
2182instructions. They require two operands, execute an operation on them,
2183and produce a single value. The resulting value of the bitwise binary
2184operators is always the same type as its first operand.</p>
2185</div>
2186
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2187<!-- _______________________________________________________________________ -->
2188<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2189Instruction</a> </div>
2190<div class="doc_text">
2191<h5>Syntax:</h5>
2192<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2193</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2194
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2195<h5>Overview:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2196
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2197<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2198the left a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2199
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2200<h5>Arguments:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2201
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2202<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
2203 href="#t_integer">integer</a> type.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2204
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2205<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2206
2207<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup>. If
2208<tt>var2</tt> is (statically or dynamically) equal to or larger than the number
2209of bits in <tt>var1</tt>, the result is undefined.</p>
2210
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2211<h5>Example:</h5><pre>
2212 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2213 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2214 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2215 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2216</pre>
2217</div>
2218<!-- _______________________________________________________________________ -->
2219<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2220Instruction</a> </div>
2221<div class="doc_text">
2222<h5>Syntax:</h5>
2223<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2224</pre>
2225
2226<h5>Overview:</h5>
2227<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2228operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2229
2230<h5>Arguments:</h5>
2231<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
2232<a href="#t_integer">integer</a> type.</p>
2233
2234<h5>Semantics:</h5>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2235
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2236<p>This instruction always performs a logical shift right operation. The most
2237significant bits of the result will be filled with zero bits after the
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2238shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
2239the number of bits in <tt>var1</tt>, the result is undefined.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2240
2241<h5>Example:</h5>
2242<pre>
2243 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2244 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2245 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2246 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2247 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2248</pre>
2249</div>
2250
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2251<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2252<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2253Instruction</a> </div>
2254<div class="doc_text">
2255
2256<h5>Syntax:</h5>
2257<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2258</pre>
2259
2260<h5>Overview:</h5>
2261<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2262operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2263
2264<h5>Arguments:</h5>
2265<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
2266<a href="#t_integer">integer</a> type.</p>
2267
2268<h5>Semantics:</h5>
2269<p>This instruction always performs an arithmetic shift right operation,
2270The most significant bits of the result will be filled with the sign bit
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2271of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
2272larger than the number of bits in <tt>var1</tt>, the result is undefined.
2273</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2274
2275<h5>Example:</h5>
2276<pre>
2277 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2278 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2279 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2280 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]2281 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2282</pre>
2283</div>
2284
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2285<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2286<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2287Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2288<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2289<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2290<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]2291</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2292<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2293<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2294its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2295<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2296<p>The two arguments to the '<tt>and</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2297 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2298identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2299<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2300<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2301<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2302<div style="align: center">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2303<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2304 <tbody>
2305 <tr>
2306 <td>In0</td>
2307 <td>In1</td>
2308 <td>Out</td>
2309 </tr>
2310 <tr>
2311 <td>0</td>
2312 <td>0</td>
2313 <td>0</td>
2314 </tr>
2315 <tr>
2316 <td>0</td>
2317 <td>1</td>
2318 <td>0</td>
2319 </tr>
2320 <tr>
2321 <td>1</td>
2322 <td>0</td>
2323 <td>0</td>
2324 </tr>
2325 <tr>
2326 <td>1</td>
2327 <td>1</td>
2328 <td>1</td>
2329 </tr>
2330 </tbody>
2331</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2332</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2333<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2334<pre> &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
2335 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2336 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2337</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2338</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2339<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2340<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2341<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2342<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2343<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]2344</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2345<h5>Overview:</h5>
2346<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2347or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2348<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2349<p>The two arguments to the '<tt>or</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2350 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2351identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2352<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2353<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2354<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2355<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2356<table border="1" cellspacing="0" cellpadding="4">
2357 <tbody>
2358 <tr>
2359 <td>In0</td>
2360 <td>In1</td>
2361 <td>Out</td>
2362 </tr>
2363 <tr>
2364 <td>0</td>
2365 <td>0</td>
2366 <td>0</td>
2367 </tr>
2368 <tr>
2369 <td>0</td>
2370 <td>1</td>
2371 <td>1</td>
2372 </tr>
2373 <tr>
2374 <td>1</td>
2375 <td>0</td>
2376 <td>1</td>
2377 </tr>
2378 <tr>
2379 <td>1</td>
2380 <td>1</td>
2381 <td>1</td>
2382 </tr>
2383 </tbody>
2384</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2385</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2386<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2387<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2388 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2389 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2390</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2391</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2392<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2393<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2394Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2395<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2396<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2397<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]2398</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2399<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2400<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2401or of its two operands. The <tt>xor</tt> is used to implement the
2402"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2403<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2404<p>The two arguments to the '<tt>xor</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2405 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2406identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2407<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2408<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2409<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2410<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2411<table border="1" cellspacing="0" cellpadding="4">
2412 <tbody>
2413 <tr>
2414 <td>In0</td>
2415 <td>In1</td>
2416 <td>Out</td>
2417 </tr>
2418 <tr>
2419 <td>0</td>
2420 <td>0</td>
2421 <td>0</td>
2422 </tr>
2423 <tr>
2424 <td>0</td>
2425 <td>1</td>
2426 <td>1</td>
2427 </tr>
2428 <tr>
2429 <td>1</td>
2430 <td>0</td>
2431 <td>1</td>
2432 </tr>
2433 <tr>
2434 <td>1</td>
2435 <td>1</td>
2436 <td>0</td>
2437 </tr>
2438 </tbody>
2439</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2440</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2441<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2442<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2443<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2444 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2445 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2446 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2447</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2448</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2449
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2450<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2451<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2452 <a name="vectorops">Vector Operations</a>
2453</div>
2454
2455<div class="doc_text">
2456
2457<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2458target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2459vector-specific operations needed to process vectors effectively. While LLVM
2460does directly support these vector operations, many sophisticated algorithms
2461will want to use target-specific intrinsics to take full advantage of a specific
2462target.</p>
2463
2464</div>
2465
2466<!-- _______________________________________________________________________ -->
2467<div class="doc_subsubsection">
2468 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2469</div>
2470
2471<div class="doc_text">
2472
2473<h5>Syntax:</h5>
2474
2475<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2476 &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]2477</pre>
2478
2479<h5>Overview:</h5>
2480
2481<p>
2482The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2483element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2484</p>
2485
2486
2487<h5>Arguments:</h5>
2488
2489<p>
2490The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2491value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2492an index indicating the position from which to extract the element.
2493The index may be a variable.</p>
2494
2495<h5>Semantics:</h5>
2496
2497<p>
2498The result is a scalar of the same type as the element type of
2499<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2500<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2501results are undefined.
2502</p>
2503
2504<h5>Example:</h5>
2505
2506<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2507 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2508</pre>
2509</div>
2510
2511
2512<!-- _______________________________________________________________________ -->
2513<div class="doc_subsubsection">
2514 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2515</div>
2516
2517<div class="doc_text">
2518
2519<h5>Syntax:</h5>
2520
2521<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2522 &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]2523</pre>
2524
2525<h5>Overview:</h5>
2526
2527<p>
2528The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2529element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2530</p>
2531
2532
2533<h5>Arguments:</h5>
2534
2535<p>
2536The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2537value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2538scalar value whose type must equal the element type of the first
2539operand. The third operand is an index indicating the position at
2540which to insert the value. The index may be a variable.</p>
2541
2542<h5>Semantics:</h5>
2543
2544<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2545The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2546element values are those of <tt>val</tt> except at position
2547<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2548exceeds the length of <tt>val</tt>, the results are undefined.
2549</p>
2550
2551<h5>Example:</h5>
2552
2553<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2554 %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]2555</pre>
2556</div>
2557
2558<!-- _______________________________________________________________________ -->
2559<div class="doc_subsubsection">
2560 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2561</div>
2562
2563<div class="doc_text">
2564
2565<h5>Syntax:</h5>
2566
2567<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2568 &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]2569</pre>
2570
2571<h5>Overview:</h5>
2572
2573<p>
2574The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2575from two input vectors, returning a vector of the same type.
2576</p>
2577
2578<h5>Arguments:</h5>
2579
2580<p>
2581The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2582with types that match each other and types that match the result of the
2583instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2584of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2585</p>
2586
2587<p>
2588The shuffle mask operand is required to be a constant vector with either
2589constant integer or undef values.
2590</p>
2591
2592<h5>Semantics:</h5>
2593
2594<p>
2595The elements of the two input vectors are numbered from left to right across
2596both of the vectors. The shuffle mask operand specifies, for each element of
2597the result vector, which element of the two input registers the result element
2598gets. The element selector may be undef (meaning "don't care") and the second
2599operand may be undef if performing a shuffle from only one vector.
2600</p>
2601
2602<h5>Example:</h5>
2603
2604<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2605 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2606 &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]2607 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2608 &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]2609</pre>
2610</div>
2611
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]2612
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2613<!-- ======================================================================= -->
2614<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2615 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2616</div>
2617
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2618<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2619
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2620<p>A key design point of an SSA-based representation is how it
2621represents memory. In LLVM, no memory locations are in SSA form, which
2622makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2623allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2624
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2625</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2626
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2627<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2628<div class="doc_subsubsection">
2629 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
2630</div>
2631
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2632<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2633
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2634<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2635
2636<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2637 &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]2638</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2639
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2640<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2641
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2642<p>The '<tt>malloc</tt>' instruction allocates memory from the system
2643heap and returns a pointer to it.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2644
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2645<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2646
2647<p>The '<tt>malloc</tt>' instruction allocates
2648<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]2649bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2650appropriate type to the program. If "NumElements" is specified, it is the
2651number of elements allocated. If an alignment is specified, the value result
2652of the allocation is guaranteed to be aligned to at least that boundary. If
2653not specified, or if zero, the target can choose to align the allocation on any
2654convenient boundary.</p>
2655
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2656<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2657
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2658<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2659
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2660<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
2661a pointer is returned.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2662
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2663<h5>Example:</h5>
2664
2665<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2666 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2667
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2668 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
2669 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
2670 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
2671 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
2672 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2673</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2674</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2675
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2676<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2677<div class="doc_subsubsection">
2678 <a name="i_free">'<tt>free</tt>' Instruction</a>
2679</div>
2680
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2681<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2682
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2683<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2684
2685<pre>
2686 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2687</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2688
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2689<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2690
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2691<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2692memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2693
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2694<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2695
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2696<p>'<tt>value</tt>' shall be a pointer value that points to a value
2697that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
2698instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2699
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2700<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2701
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2702<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2703after this instruction executes.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2704
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2705<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2706
2707<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2708 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
2709 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2710</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2711</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2712
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2713<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2714<div class="doc_subsubsection">
2715 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
2716</div>
2717
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2718<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2719
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2720<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2721
2722<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2723 &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]2724</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2725
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2726<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2727
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2728<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
2729currently executing function, to be automatically released when this function
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2730returns to its caller.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2731
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2732<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2733
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2734<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2735bytes of memory on the runtime stack, returning a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2736appropriate type to the program. If "NumElements" is specified, it is the
2737number of elements allocated. If an alignment is specified, the value result
2738of the allocation is guaranteed to be aligned to at least that boundary. If
2739not specified, or if zero, the target can choose to align the allocation on any
2740convenient boundary.</p>
2741
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2742<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2743
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2744<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2745
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2746<p>Memory is allocated; a pointer is returned. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2747memory is automatically released when the function returns. The '<tt>alloca</tt>'
2748instruction is commonly used to represent automatic variables that must
2749have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]2750 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]2751instructions), the memory is reclaimed.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2752
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2753<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2754
2755<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2756 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2757 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
2758 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2759 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2760</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2761</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2762
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2763<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2764<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
2765Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2766<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2767<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2768<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]2769<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2770<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2771<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2772<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2773address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]2774 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2775marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2776the number or order of execution of this <tt>load</tt> with other
2777volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
2778instructions. </p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2779<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2780<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2781<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2782<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2783 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2784 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
2785 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2786</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2787</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2788<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2789<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
2790Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]2791<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2792<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2793<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
2794 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]2795</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2796<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2797<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2798<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2799<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2800to 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]2801operand must be a pointer to the type of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2802operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2803optimizer is not allowed to modify the number or order of execution of
2804this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
2805 href="#i_store">store</a></tt> instructions.</p>
2806<h5>Semantics:</h5>
2807<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
2808at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2809<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2810<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]2811 store i32 3, i32* %ptr <i>; yields {void}</i>
2812 %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]2813</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2814</div>
2815
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2816<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2817<div class="doc_subsubsection">
2818 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
2819</div>
2820
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2821<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2822<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2823<pre>
2824 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
2825</pre>
2826
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2827<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2828
2829<p>
2830The '<tt>getelementptr</tt>' instruction is used to get the address of a
2831subelement of an aggregate data structure.</p>
2832
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2833<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2834
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2835<p>This instruction takes a list of integer operands that indicate what
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2836elements of the aggregate object to index to. The actual types of the arguments
2837provided depend on the type of the first pointer argument. The
2838'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]2839levels 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]2840structure, only <tt>i32</tt> integer constants are allowed. When indexing
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2841into an array or pointer, only integers of 32 or 64 bits are allowed, and will
2842be sign extended to 64-bit values.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2843
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2844<p>For example, let's consider a C code fragment and how it gets
2845compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2846
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2847<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2848<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2849struct RT {
2850 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2851 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2852 char C;
2853};
2854struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2855 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2856 double Y;
2857 struct RT Z;
2858};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2859
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2860int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2861 return &amp;s[1].Z.B[5][13];
2862}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2863</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2864</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2865
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2866<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2867
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2868<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2869<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2870%RT = type { i8 , [10 x [20 x i32]], i8 }
2871%ST = type { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2872
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2873define i32* %foo(%ST* %s) {
2874entry:
2875 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
2876 ret i32* %reg
2877}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2878</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2879</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2880
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2881<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2882
2883<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2884on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2885and <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]2886<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]2887to 64-bits. <a href="#t_struct">Structure</a> types require <tt>i32</tt>
Reid Spencer42ddd842006-12-03 16:53:48 +0000[diff] [blame]2888<b>constants</b>.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2889
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2890<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]2891type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2892}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2893the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
2894i8 }</tt>' type, another structure. The third index indexes into the second
2895element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2896array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2897'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
2898to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2899
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2900<p>Note that it is perfectly legal to index partially through a
2901structure, returning a pointer to an inner element. Because of this,
2902the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2903
2904<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2905 define i32* %foo(%ST* %s) {
2906 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2907 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
2908 %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]2909 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
2910 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
2911 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2912 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2913</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2914
2915<p>Note that it is undefined to access an array out of bounds: array and
2916pointer indexes must always be within the defined bounds of the array type.
2917The one exception for this rules is zero length arrays. These arrays are
2918defined to be accessible as variable length arrays, which requires access
2919beyond the zero'th element.</p>
2920
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2921<p>The getelementptr instruction is often confusing. For some more insight
2922into how it works, see <a href="GetElementPtr.html">the getelementptr
2923FAQ</a>.</p>
2924
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2925<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2926
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2927<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2928 <i>; yields [12 x i8]*:aptr</i>
2929 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2930</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2931</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2932
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2933<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]2934<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2935</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2936<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]2937<p>The instructions in this category are the conversion instructions (casting)
2938which all take a single operand and a type. They perform various bit conversions
2939on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2940</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]2941
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2942<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]2943<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2944 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
2945</div>
2946<div class="doc_text">
2947
2948<h5>Syntax:</h5>
2949<pre>
2950 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2951</pre>
2952
2953<h5>Overview:</h5>
2954<p>
2955The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
2956</p>
2957
2958<h5>Arguments:</h5>
2959<p>
2960The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
2961be 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]2962and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2963type. The bit size of <tt>value</tt> must be larger than the bit size of
2964<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2965
2966<h5>Semantics:</h5>
2967<p>
2968The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2969and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
2970larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
2971It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2972
2973<h5>Example:</h5>
2974<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2975 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2976 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
2977 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2978</pre>
2979</div>
2980
2981<!-- _______________________________________________________________________ -->
2982<div class="doc_subsubsection">
2983 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
2984</div>
2985<div class="doc_text">
2986
2987<h5>Syntax:</h5>
2988<pre>
2989 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2990</pre>
2991
2992<h5>Overview:</h5>
2993<p>The '<tt>zext</tt>' instruction zero extends its operand to type
2994<tt>ty2</tt>.</p>
2995
2996
2997<h5>Arguments:</h5>
2998<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]2999<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3000also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3001<tt>value</tt> must be smaller than the bit size of the destination type,
3002<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3003
3004<h5>Semantics:</h5>
3005<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]3006bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3007
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]3008<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]3009
3010<h5>Example:</h5>
3011<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3012 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3013 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3014</pre>
3015</div>
3016
3017<!-- _______________________________________________________________________ -->
3018<div class="doc_subsubsection">
3019 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3020</div>
3021<div class="doc_text">
3022
3023<h5>Syntax:</h5>
3024<pre>
3025 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3026</pre>
3027
3028<h5>Overview:</h5>
3029<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3030
3031<h5>Arguments:</h5>
3032<p>
3033The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3034<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3035also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3036<tt>value</tt> must be smaller than the bit size of the destination type,
3037<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3038
3039<h5>Semantics:</h5>
3040<p>
3041The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3042bit (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]3043the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3044
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3045<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]3046
3047<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3048<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3049 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3050 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3051</pre>
3052</div>
3053
3054<!-- _______________________________________________________________________ -->
3055<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3056 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3057</div>
3058
3059<div class="doc_text">
3060
3061<h5>Syntax:</h5>
3062
3063<pre>
3064 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3065</pre>
3066
3067<h5>Overview:</h5>
3068<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3069<tt>ty2</tt>.</p>
3070
3071
3072<h5>Arguments:</h5>
3073<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3074 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3075cast it to. The size of <tt>value</tt> must be larger than the size of
3076<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3077<i>no-op cast</i>.</p>
3078
3079<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3080<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3081<a href="#t_floating">floating point</a> type to a smaller
3082<a href="#t_floating">floating point</a> type. If the value cannot fit within
3083the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3084
3085<h5>Example:</h5>
3086<pre>
3087 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3088 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3089</pre>
3090</div>
3091
3092<!-- _______________________________________________________________________ -->
3093<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3094 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3095</div>
3096<div class="doc_text">
3097
3098<h5>Syntax:</h5>
3099<pre>
3100 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3101</pre>
3102
3103<h5>Overview:</h5>
3104<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3105floating point value.</p>
3106
3107<h5>Arguments:</h5>
3108<p>The '<tt>fpext</tt>' instruction takes a
3109<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3110and a <a href="#t_floating">floating point</a> type to cast it to. The source
3111type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3112
3113<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3114<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3115<a href="#t_floating">floating point</a> type to a larger
3116<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3117used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3118<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]3119
3120<h5>Example:</h5>
3121<pre>
3122 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3123 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3124</pre>
3125</div>
3126
3127<!-- _______________________________________________________________________ -->
3128<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3129 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3130</div>
3131<div class="doc_text">
3132
3133<h5>Syntax:</h5>
3134<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3135 &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]3136</pre>
3137
3138<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3139<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3140unsigned integer equivalent of type <tt>ty2</tt>.
3141</p>
3142
3143<h5>Arguments:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3144<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]3145scalar or vector <a href="#t_floating">floating point</a> value, and a type
3146to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3147type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3148vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3149
3150<h5>Semantics:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3151<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3152<a href="#t_floating">floating point</a> operand into the nearest (rounding
3153towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3154the results are undefined.</p>
3155
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3156<h5>Example:</h5>
3157<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3158 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3159 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]3160 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3161</pre>
3162</div>
3163
3164<!-- _______________________________________________________________________ -->
3165<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3166 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3167</div>
3168<div class="doc_text">
3169
3170<h5>Syntax:</h5>
3171<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3172 &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]3173</pre>
3174
3175<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3176<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3177<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]3178</p>
3179
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3180<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3181<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]3182scalar or vector <a href="#t_floating">floating point</a> value, and a type
3183to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3184type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3185vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3186
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3187<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3188<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3189<a href="#t_floating">floating point</a> operand into the nearest (rounding
3190towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3191the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3192
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3193<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3194<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3195 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]3196 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3197 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3198</pre>
3199</div>
3200
3201<!-- _______________________________________________________________________ -->
3202<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3203 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3204</div>
3205<div class="doc_text">
3206
3207<h5>Syntax:</h5>
3208<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3209 &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]3210</pre>
3211
3212<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3213<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3214integer and converts that value to the <tt>ty2</tt> type.</p>
3215
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3216<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3217<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3218scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3219to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3220type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3221floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3222
3223<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3224<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3225integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3226the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3227
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3228<h5>Example:</h5>
3229<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3230 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3231 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3232</pre>
3233</div>
3234
3235<!-- _______________________________________________________________________ -->
3236<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3237 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3238</div>
3239<div class="doc_text">
3240
3241<h5>Syntax:</h5>
3242<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3243 &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]3244</pre>
3245
3246<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3247<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3248integer and converts that value to the <tt>ty2</tt> type.</p>
3249
3250<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]3251<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3252scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3253to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3254type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3255floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3256
3257<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3258<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3259integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3260the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3261
3262<h5>Example:</h5>
3263<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3264 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3265 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3266</pre>
3267</div>
3268
3269<!-- _______________________________________________________________________ -->
3270<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3271 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3272</div>
3273<div class="doc_text">
3274
3275<h5>Syntax:</h5>
3276<pre>
3277 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3278</pre>
3279
3280<h5>Overview:</h5>
3281<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3282the integer type <tt>ty2</tt>.</p>
3283
3284<h5>Arguments:</h5>
3285<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3286must 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]3287<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3288
3289<h5>Semantics:</h5>
3290<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3291<tt>ty2</tt> by interpreting the pointer value as an integer and either
3292truncating or zero extending that value to the size of the integer type. If
3293<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3294<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]3295are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3296change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3297
3298<h5>Example:</h5>
3299<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3300 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3301 %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]3302</pre>
3303</div>
3304
3305<!-- _______________________________________________________________________ -->
3306<div class="doc_subsubsection">
3307 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3308</div>
3309<div class="doc_text">
3310
3311<h5>Syntax:</h5>
3312<pre>
3313 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3314</pre>
3315
3316<h5>Overview:</h5>
3317<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3318a pointer type, <tt>ty2</tt>.</p>
3319
3320<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3321<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3322value to cast, and a type to cast it to, which must be a
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]3323<a href="#t_pointer">pointer</a> type.
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3324
3325<h5>Semantics:</h5>
3326<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3327<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3328the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3329size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3330the size of a pointer then a zero extension is done. If they are the same size,
3331nothing is done (<i>no-op cast</i>).</p>
3332
3333<h5>Example:</h5>
3334<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3335 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3336 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3337 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3338</pre>
3339</div>
3340
3341<!-- _______________________________________________________________________ -->
3342<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3343 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3344</div>
3345<div class="doc_text">
3346
3347<h5>Syntax:</h5>
3348<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3349 &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]3350</pre>
3351
3352<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3353<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3354<tt>ty2</tt> without changing any bits.</p>
3355
3356<h5>Arguments:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3357<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3358a first class value, and a type to cast it to, which must also be a <a
3359 href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]3360and the destination type, <tt>ty2</tt>, must be identical. If the source
3361type is a pointer, the destination type must also be a pointer.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3362
3363<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3364<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3365<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3366this conversion. The conversion is done as if the <tt>value</tt> had been
3367stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3368converted to other pointer types with this instruction. To convert pointers to
3369other types, use the <a href="#i_inttoptr">inttoptr</a> or
3370<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3371
3372<h5>Example:</h5>
3373<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3374 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3375 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3376 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3377</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3378</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3379
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3380<!-- ======================================================================= -->
3381<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3382<div class="doc_text">
3383<p>The instructions in this category are the "miscellaneous"
3384instructions, which defy better classification.</p>
3385</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3386
3387<!-- _______________________________________________________________________ -->
3388<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3389</div>
3390<div class="doc_text">
3391<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3392<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]3393</pre>
3394<h5>Overview:</h5>
3395<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
3396of its two integer operands.</p>
3397<h5>Arguments:</h5>
3398<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3399the condition code indicating the kind of comparison to perform. It is not
3400a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3401<ol>
3402 <li><tt>eq</tt>: equal</li>
3403 <li><tt>ne</tt>: not equal </li>
3404 <li><tt>ugt</tt>: unsigned greater than</li>
3405 <li><tt>uge</tt>: unsigned greater or equal</li>
3406 <li><tt>ult</tt>: unsigned less than</li>
3407 <li><tt>ule</tt>: unsigned less or equal</li>
3408 <li><tt>sgt</tt>: signed greater than</li>
3409 <li><tt>sge</tt>: signed greater or equal</li>
3410 <li><tt>slt</tt>: signed less than</li>
3411 <li><tt>sle</tt>: signed less or equal</li>
3412</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3413<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3414<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3415<h5>Semantics:</h5>
3416<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3417the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3418yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3419<ol>
3420 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3421 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3422 </li>
3423 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3424 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3425 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
3426 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3427 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
3428 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3429 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
3430 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3431 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
3432 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
3433 <li><tt>sgt</tt>: interprets the operands as signed values and yields
3434 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3435 <li><tt>sge</tt>: interprets the operands as signed values and yields
3436 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3437 <li><tt>slt</tt>: interprets the operands as signed values and yields
3438 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3439 <li><tt>sle</tt>: interprets the operands as signed values and yields
3440 <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]3441</ol>
3442<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3443values are compared as if they were integers.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3444
3445<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3446<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3447 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3448 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3449 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3450 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3451 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3452</pre>
3453</div>
3454
3455<!-- _______________________________________________________________________ -->
3456<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3457</div>
3458<div class="doc_text">
3459<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3460<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]3461</pre>
3462<h5>Overview:</h5>
3463<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
3464of its floating point operands.</p>
3465<h5>Arguments:</h5>
3466<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3467the condition code indicating the kind of comparison to perform. It is not
3468a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3469<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3470 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3471 <li><tt>oeq</tt>: ordered and equal</li>
3472 <li><tt>ogt</tt>: ordered and greater than </li>
3473 <li><tt>oge</tt>: ordered and greater than or equal</li>
3474 <li><tt>olt</tt>: ordered and less than </li>
3475 <li><tt>ole</tt>: ordered and less than or equal</li>
3476 <li><tt>one</tt>: ordered and not equal</li>
3477 <li><tt>ord</tt>: ordered (no nans)</li>
3478 <li><tt>ueq</tt>: unordered or equal</li>
3479 <li><tt>ugt</tt>: unordered or greater than </li>
3480 <li><tt>uge</tt>: unordered or greater than or equal</li>
3481 <li><tt>ult</tt>: unordered or less than </li>
3482 <li><tt>ule</tt>: unordered or less than or equal</li>
3483 <li><tt>une</tt>: unordered or not equal</li>
3484 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3485 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3486</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3487<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]3488<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3489<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
3490<a href="#t_floating">floating point</a> typed. They must have identical
3491types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3492<h5>Semantics:</h5>
3493<p>The '<tt>fcmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3494the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3495yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3496<ol>
3497 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3498 <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]3499 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3500 <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]3501 <tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3502 <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]3503 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3504 <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]3505 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3506 <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]3507 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3508 <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]3509 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3510 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3511 <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]3512 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3513 <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]3514 <tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3515 <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]3516 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3517 <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]3518 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3519 <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]3520 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3521 <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]3522 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3523 <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]3524 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
3525</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3526
3527<h5>Example:</h5>
3528<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
3529 &lt;result&gt; = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
3530 &lt;result&gt; = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
3531 &lt;result&gt; = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
3532</pre>
3533</div>
3534
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3535<!-- _______________________________________________________________________ -->
3536<div class="doc_subsubsection"> <a name="i_phi">'<tt>phi</tt>'
3537Instruction</a> </div>
3538<div class="doc_text">
3539<h5>Syntax:</h5>
3540<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
3541<h5>Overview:</h5>
3542<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
3543the SSA graph representing the function.</p>
3544<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3545<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3546field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
3547as arguments, with one pair for each predecessor basic block of the
3548current block. Only values of <a href="#t_firstclass">first class</a>
3549type may be used as the value arguments to the PHI node. Only labels
3550may be used as the label arguments.</p>
3551<p>There must be no non-phi instructions between the start of a basic
3552block and the PHI instructions: i.e. PHI instructions must be first in
3553a basic block.</p>
3554<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3555<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
3556specified by the pair corresponding to the predecessor basic block that executed
3557just prior to the current block.</p>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3558<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3559<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]3560</div>
3561
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3562<!-- _______________________________________________________________________ -->
3563<div class="doc_subsubsection">
3564 <a name="i_select">'<tt>select</tt>' Instruction</a>
3565</div>
3566
3567<div class="doc_text">
3568
3569<h5>Syntax:</h5>
3570
3571<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3572 &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]3573</pre>
3574
3575<h5>Overview:</h5>
3576
3577<p>
3578The '<tt>select</tt>' instruction is used to choose one value based on a
3579condition, without branching.
3580</p>
3581
3582
3583<h5>Arguments:</h5>
3584
3585<p>
3586The '<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.
3587</p>
3588
3589<h5>Semantics:</h5>
3590
3591<p>
3592If the boolean condition evaluates to true, the instruction returns the first
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3593value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3594</p>
3595
3596<h5>Example:</h5>
3597
3598<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3599 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3600</pre>
3601</div>
3602
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]3603
3604<!-- _______________________________________________________________________ -->
3605<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3606 <a name="i_call">'<tt>call</tt>' Instruction</a>
3607</div>
3608
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3609<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3610
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3611<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3612<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3613 &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]3614</pre>
3615
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3616<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3617
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3618<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3619
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3620<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3621
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3622<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3623
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3624<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3625 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3626 <p>The optional "tail" marker indicates whether the callee function accesses
3627 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3628 function call is eligible for tail call optimization. Note that calls may
3629 be marked "tail" even if they do not occur before a <a
3630 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3631 </li>
3632 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3633 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3634 convention</a> the call should use. If none is specified, the call defaults
3635 to using C calling conventions.
3636 </li>
3637 <li>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3638 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
3639 the type of the return value. Functions that return no value are marked
3640 <tt><a href="#t_void">void</a></tt>.</p>
3641 </li>
3642 <li>
3643 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
3644 value being invoked. The argument types must match the types implied by
3645 this signature. This type can be omitted if the function is not varargs
3646 and if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3647 </li>
3648 <li>
3649 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
3650 be invoked. In most cases, this is a direct function invocation, but
3651 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3652 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3653 </li>
3654 <li>
3655 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]3656 function signature argument types. All arguments must be of
3657 <a href="#t_firstclass">first class</a> type. If the function signature
3658 indicates the function accepts a variable number of arguments, the extra
3659 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3660 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3661</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3662
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3663<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3664
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3665<p>The '<tt>call</tt>' instruction is used to cause control flow to
3666transfer to a specified function, with its incoming arguments bound to
3667the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
3668instruction in the called function, control flow continues with the
3669instruction after the function call, and the return value of the
3670function is bound to the result argument. This is a simpler case of
3671the <a href="#i_invoke">invoke</a> instruction.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3672
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3673<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3674
3675<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]3676 %retval = call i32 @test(i32 %argc)
3677 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42);
3678 %X = tail call i32 @foo()
3679 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo()
3680 %Z = call void %foo(i8 97 signext)
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3681</pre>
3682
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3683</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3684
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3685<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3686<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3687 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3688</div>
3689
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3690<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3691
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3692<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3693
3694<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3695 &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]3696</pre>
3697
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3698<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3699
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3700<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3701the "variable argument" area of a function call. It is used to implement the
3702<tt>va_arg</tt> macro in C.</p>
3703
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3704<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3705
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3706<p>This instruction takes a <tt>va_list*</tt> value and the type of
3707the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3708increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3709actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3710
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3711<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3712
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3713<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
3714type from the specified <tt>va_list</tt> and causes the
3715<tt>va_list</tt> to point to the next argument. For more information,
3716see the variable argument handling <a href="#int_varargs">Intrinsic
3717Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3718
3719<p>It is legal for this instruction to be called in a function which does not
3720take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3721function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3722
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3723<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3724href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3725argument.</p>
3726
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3727<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3728
3729<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
3730
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3731</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3732
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3733<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3734<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
3735<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3736
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3737<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3738
3739<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3740well known names and semantics and are required to follow certain restrictions.
3741Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3742language that does not require changing all of the transformations in LLVM when
Gabor Greif04367bf2007-07-06 22:07:22 +0000[diff] [blame]3743adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3744
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3745<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3746prefix is reserved in LLVM for intrinsic names; thus, function names may not
3747begin with this prefix. Intrinsic functions must always be external functions:
3748you cannot define the body of intrinsic functions. Intrinsic functions may
3749only be used in call or invoke instructions: it is illegal to take the address
3750of an intrinsic function. Additionally, because intrinsic functions are part
3751of the LLVM language, it is required if any are added that they be documented
3752here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3753
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]3754<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
3755a family of functions that perform the same operation but on different data
3756types. Because LLVM can represent over 8 million different integer types,
3757overloading is used commonly to allow an intrinsic function to operate on any
3758integer type. One or more of the argument types or the result type can be
3759overloaded to accept any integer type. Argument types may also be defined as
3760exactly matching a previous argument's type or the result type. This allows an
3761intrinsic function which accepts multiple arguments, but needs all of them to
3762be of the same type, to only be overloaded with respect to a single argument or
3763the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3764
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]3765<p>Overloaded intrinsics will have the names of its overloaded argument types
3766encoded into its function name, each preceded by a period. Only those types
3767which are overloaded result in a name suffix. Arguments whose type is matched
3768against another type do not. For example, the <tt>llvm.ctpop</tt> function can
3769take an integer of any width and returns an integer of exactly the same integer
3770width. This leads to a family of functions such as
3771<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
3772Only one type, the return type, is overloaded, and only one type suffix is
3773required. Because the argument's type is matched against the return type, it
3774does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3775
3776<p>To learn how to add an intrinsic function, please see the
3777<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3778</p>
3779
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3780</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3781
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3782<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3783<div class="doc_subsection">
3784 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
3785</div>
3786
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3787<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3788
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3789<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3790 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3791intrinsic functions. These functions are related to the similarly
3792named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3793
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3794<p>All of these functions operate on arguments that use a
3795target-specific value type "<tt>va_list</tt>". The LLVM assembly
3796language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3797transformations should be prepared to handle these functions regardless of
3798the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3799
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]3800<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]3801instruction and the variable argument handling intrinsic functions are
3802used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3803
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3804<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3805<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3806define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3807 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3808 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3809 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3810 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3811
3812 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3813 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3814
3815 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3816 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3817 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3818 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3819 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3820
3821 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3822 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3823 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3824}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3825
3826declare void @llvm.va_start(i8*)
3827declare void @llvm.va_copy(i8*, i8*)
3828declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3829</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3830</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3831
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3832</div>
3833
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3834<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3835<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3836 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3837</div>
3838
3839
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3840<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3841<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3842<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3843<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3844<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
3845<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
3846href="#i_va_arg">va_arg</a></tt>.</p>
3847
3848<h5>Arguments:</h5>
3849
3850<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
3851
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3852<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3853
3854<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
3855macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3856<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]3857<tt>va_arg</tt> will produce the first variable argument passed to the function.
3858Unlike 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]3859last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3860
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3861</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3862
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3863<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3864<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3865 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3866</div>
3867
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3868<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3869<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3870<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3871<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3872
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3873<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3874which 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]3875or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3876
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3877<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3878
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3879<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]3880
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3881<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3882
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3883<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]3884macro available in C. In a target-dependent way, it destroys the
3885<tt>va_list</tt> element to which the argument points. Calls to <a
3886href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
3887<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
3888<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3889
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3890</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3891
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3892<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3893<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3894 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3895</div>
3896
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3897<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3898
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3899<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3900
3901<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3902 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3903</pre>
3904
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3905<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3906
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3907<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
3908from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3909
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3910<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3911
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3912<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]3913The 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]3914
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3915
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3916<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3917
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3918<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
3919macro available in C. In a target-dependent way, it copies the source
3920<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
3921intrinsic is necessary because the <tt><a href="#int_va_start">
3922llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
3923example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3924
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3925</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3926
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3927<!-- ======================================================================= -->
3928<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3929 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
3930</div>
3931
3932<div class="doc_text">
3933
3934<p>
3935LLVM support for <a href="GarbageCollection.html">Accurate Garbage
3936Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3937These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3938stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3939href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3940Front-ends for type-safe garbage collected languages should generate these
3941intrinsics to make use of the LLVM garbage collectors. For more details, see <a
3942href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
3943</p>
3944</div>
3945
3946<!-- _______________________________________________________________________ -->
3947<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3948 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3949</div>
3950
3951<div class="doc_text">
3952
3953<h5>Syntax:</h5>
3954
3955<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]3956 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3957</pre>
3958
3959<h5>Overview:</h5>
3960
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3961<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]3962the code generator, and allows some metadata to be associated with it.</p>
3963
3964<h5>Arguments:</h5>
3965
3966<p>The first argument specifies the address of a stack object that contains the
3967root pointer. The second pointer (which must be either a constant or a global
3968value address) contains the meta-data to be associated with the root.</p>
3969
3970<h5>Semantics:</h5>
3971
3972<p>At runtime, a call to this intrinsics stores a null pointer into the "ptrloc"
3973location. At compile-time, the code generator generates information to allow
3974the runtime to find the pointer at GC safe points.
3975</p>
3976
3977</div>
3978
3979
3980<!-- _______________________________________________________________________ -->
3981<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3982 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3983</div>
3984
3985<div class="doc_text">
3986
3987<h5>Syntax:</h5>
3988
3989<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]3990 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3991</pre>
3992
3993<h5>Overview:</h5>
3994
3995<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
3996locations, allowing garbage collector implementations that require read
3997barriers.</p>
3998
3999<h5>Arguments:</h5>
4000
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4001<p>The second argument is the address to read from, which should be an address
4002allocated from the garbage collector. The first object is a pointer to the
4003start of the referenced object, if needed by the language runtime (otherwise
4004null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4005
4006<h5>Semantics:</h5>
4007
4008<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4009instruction, but may be replaced with substantially more complex code by the
4010garbage collector runtime, as needed.</p>
4011
4012</div>
4013
4014
4015<!-- _______________________________________________________________________ -->
4016<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4017 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4018</div>
4019
4020<div class="doc_text">
4021
4022<h5>Syntax:</h5>
4023
4024<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4025 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4026</pre>
4027
4028<h5>Overview:</h5>
4029
4030<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4031locations, allowing garbage collector implementations that require write
4032barriers (such as generational or reference counting collectors).</p>
4033
4034<h5>Arguments:</h5>
4035
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]4036<p>The first argument is the reference to store, the second is the start of the
4037object to store it to, and the third is the address of the field of Obj to
4038store to. If the runtime does not require a pointer to the object, Obj may be
4039null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]4040
4041<h5>Semantics:</h5>
4042
4043<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4044instruction, but may be replaced with substantially more complex code by the
4045garbage collector runtime, as needed.</p>
4046
4047</div>
4048
4049
4050
4051<!-- ======================================================================= -->
4052<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4053 <a name="int_codegen">Code Generator Intrinsics</a>
4054</div>
4055
4056<div class="doc_text">
4057<p>
4058These intrinsics are provided by LLVM to expose special features that may only
4059be implemented with code generator support.
4060</p>
4061
4062</div>
4063
4064<!-- _______________________________________________________________________ -->
4065<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4066 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4067</div>
4068
4069<div class="doc_text">
4070
4071<h5>Syntax:</h5>
4072<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4073 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4074</pre>
4075
4076<h5>Overview:</h5>
4077
4078<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4079The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4080target-specific value indicating the return address of the current function
4081or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4082</p>
4083
4084<h5>Arguments:</h5>
4085
4086<p>
4087The argument to this intrinsic indicates which function to return the address
4088for. Zero indicates the calling function, one indicates its caller, etc. The
4089argument is <b>required</b> to be a constant integer value.
4090</p>
4091
4092<h5>Semantics:</h5>
4093
4094<p>
4095The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4096the return address of the specified call frame, or zero if it cannot be
4097identified. The value returned by this intrinsic is likely to be incorrect or 0
4098for arguments other than zero, so it should only be used for debugging purposes.
4099</p>
4100
4101<p>
4102Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4103aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4104source-language caller.
4105</p>
4106</div>
4107
4108
4109<!-- _______________________________________________________________________ -->
4110<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4111 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4112</div>
4113
4114<div class="doc_text">
4115
4116<h5>Syntax:</h5>
4117<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4118 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4119</pre>
4120
4121<h5>Overview:</h5>
4122
4123<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4124The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4125target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4126</p>
4127
4128<h5>Arguments:</h5>
4129
4130<p>
4131The argument to this intrinsic indicates which function to return the frame
4132pointer for. Zero indicates the calling function, one indicates its caller,
4133etc. The argument is <b>required</b> to be a constant integer value.
4134</p>
4135
4136<h5>Semantics:</h5>
4137
4138<p>
4139The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4140the frame address of the specified call frame, or zero if it cannot be
4141identified. The value returned by this intrinsic is likely to be incorrect or 0
4142for arguments other than zero, so it should only be used for debugging purposes.
4143</p>
4144
4145<p>
4146Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4147aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4148source-language caller.
4149</p>
4150</div>
4151
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4152<!-- _______________________________________________________________________ -->
4153<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4154 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4155</div>
4156
4157<div class="doc_text">
4158
4159<h5>Syntax:</h5>
4160<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4161 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4162</pre>
4163
4164<h5>Overview:</h5>
4165
4166<p>
4167The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4168the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4169<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4170features like scoped automatic variable sized arrays in C99.
4171</p>
4172
4173<h5>Semantics:</h5>
4174
4175<p>
4176This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4177href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4178<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4179<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4180state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4181practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4182that were allocated after the <tt>llvm.stacksave</tt> was executed.
4183</p>
4184
4185</div>
4186
4187<!-- _______________________________________________________________________ -->
4188<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4189 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4190</div>
4191
4192<div class="doc_text">
4193
4194<h5>Syntax:</h5>
4195<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4196 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4197</pre>
4198
4199<h5>Overview:</h5>
4200
4201<p>
4202The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4203the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4204href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4205useful for implementing language features like scoped automatic variable sized
4206arrays in C99.
4207</p>
4208
4209<h5>Semantics:</h5>
4210
4211<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4212See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4213</p>
4214
4215</div>
4216
4217
4218<!-- _______________________________________________________________________ -->
4219<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4220 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4221</div>
4222
4223<div class="doc_text">
4224
4225<h5>Syntax:</h5>
4226<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4227 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]4228</pre>
4229
4230<h5>Overview:</h5>
4231
4232
4233<p>
4234The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4235a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4236no
4237effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]4238characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4239</p>
4240
4241<h5>Arguments:</h5>
4242
4243<p>
4244<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4245determining if the fetch should be for a read (0) or write (1), and
4246<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]4247locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4248<tt>locality</tt> arguments must be constant integers.
4249</p>
4250
4251<h5>Semantics:</h5>
4252
4253<p>
4254This intrinsic does not modify the behavior of the program. In particular,
4255prefetches cannot trap and do not produce a value. On targets that support this
4256intrinsic, the prefetch can provide hints to the processor cache for better
4257performance.
4258</p>
4259
4260</div>
4261
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4262<!-- _______________________________________________________________________ -->
4263<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4264 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4265</div>
4266
4267<div class="doc_text">
4268
4269<h5>Syntax:</h5>
4270<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]4271 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4272</pre>
4273
4274<h5>Overview:</h5>
4275
4276
4277<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4278The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
4279(PC) in a region of
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4280code to simulators and other tools. The method is target specific, but it is
4281expected that the marker will use exported symbols to transmit the PC of the marker.
Jeff Cohen25d4f7e2005-11-11 02:15:27 +0000[diff] [blame]4282The marker makes no guarantees that it will remain with any specific instruction
Chris Lattnerd07c3f42005-11-15 06:07:55 +0000[diff] [blame]4283after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]4284optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4285correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4286</p>
4287
4288<h5>Arguments:</h5>
4289
4290<p>
4291<tt>id</tt> is a numerical id identifying the marker.
4292</p>
4293
4294<h5>Semantics:</h5>
4295
4296<p>
4297This intrinsic does not modify the behavior of the program. Backends that do not
4298support this intrinisic may ignore it.
4299</p>
4300
4301</div>
4302
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4303<!-- _______________________________________________________________________ -->
4304<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4305 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4306</div>
4307
4308<div class="doc_text">
4309
4310<h5>Syntax:</h5>
4311<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4312 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4313</pre>
4314
4315<h5>Overview:</h5>
4316
4317
4318<p>
4319The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4320counter register (or similar low latency, high accuracy clocks) on those targets
4321that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4322As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4323should only be used for small timings.
4324</p>
4325
4326<h5>Semantics:</h5>
4327
4328<p>
4329When directly supported, reading the cycle counter should not modify any memory.
4330Implementations are allowed to either return a application specific value or a
4331system wide value. On backends without support, this is lowered to a constant 0.
4332</p>
4333
4334</div>
4335
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4336<!-- ======================================================================= -->
4337<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4338 <a name="int_libc">Standard C Library Intrinsics</a>
4339</div>
4340
4341<div class="doc_text">
4342<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4343LLVM provides intrinsics for a few important standard C library functions.
4344These intrinsics allow source-language front-ends to pass information about the
4345alignment of the pointer arguments to the code generator, providing opportunity
4346for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4347</p>
4348
4349</div>
4350
4351<!-- _______________________________________________________________________ -->
4352<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4353 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4354</div>
4355
4356<div class="doc_text">
4357
4358<h5>Syntax:</h5>
4359<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4360 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4361 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4362 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4363 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4364</pre>
4365
4366<h5>Overview:</h5>
4367
4368<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4369The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4370location to the destination location.
4371</p>
4372
4373<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4374Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
4375intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4376</p>
4377
4378<h5>Arguments:</h5>
4379
4380<p>
4381The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4382the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4383specifying the number of bytes to copy, and the fourth argument is the alignment
4384of the source and destination locations.
4385</p>
4386
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4387<p>
4388If 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]4389the caller guarantees that both the source and destination pointers are aligned
4390to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4391</p>
4392
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4393<h5>Semantics:</h5>
4394
4395<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4396The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4397location to the destination location, which are not allowed to overlap. It
4398copies "len" bytes of memory over. If the argument is known to be aligned to
4399some boundary, this can be specified as the fourth argument, otherwise it should
4400be set to 0 or 1.
4401</p>
4402</div>
4403
4404
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4405<!-- _______________________________________________________________________ -->
4406<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4407 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4408</div>
4409
4410<div class="doc_text">
4411
4412<h5>Syntax:</h5>
4413<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4414 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4415 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4416 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4417 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4418</pre>
4419
4420<h5>Overview:</h5>
4421
4422<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4423The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
4424location to the destination location. It is similar to the
4425'<tt>llvm.memcmp</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4426</p>
4427
4428<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4429Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
4430intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4431</p>
4432
4433<h5>Arguments:</h5>
4434
4435<p>
4436The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4437the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4438specifying the number of bytes to copy, and the fourth argument is the alignment
4439of the source and destination locations.
4440</p>
4441
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4442<p>
4443If 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]4444the caller guarantees that the source and destination pointers are aligned to
4445that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4446</p>
4447
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4448<h5>Semantics:</h5>
4449
4450<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4451The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4452location to the destination location, which may overlap. It
4453copies "len" bytes of memory over. If the argument is known to be aligned to
4454some boundary, this can be specified as the fourth argument, otherwise it should
4455be set to 0 or 1.
4456</p>
4457</div>
4458
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4459
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4460<!-- _______________________________________________________________________ -->
4461<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4462 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4463</div>
4464
4465<div class="doc_text">
4466
4467<h5>Syntax:</h5>
4468<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4469 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4470 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4471 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4472 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4473</pre>
4474
4475<h5>Overview:</h5>
4476
4477<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4478The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4479byte value.
4480</p>
4481
4482<p>
4483Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
4484does not return a value, and takes an extra alignment argument.
4485</p>
4486
4487<h5>Arguments:</h5>
4488
4489<p>
4490The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4491byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4492argument specifying the number of bytes to fill, and the fourth argument is the
4493known alignment of destination location.
4494</p>
4495
4496<p>
4497If 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]4498the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4499</p>
4500
4501<h5>Semantics:</h5>
4502
4503<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4504The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
4505the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4506destination location. If the argument is known to be aligned to some boundary,
4507this can be specified as the fourth argument, otherwise it should be set to 0 or
45081.
4509</p>
4510</div>
4511
4512
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4513<!-- _______________________________________________________________________ -->
4514<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4515 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4516</div>
4517
4518<div class="doc_text">
4519
4520<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4521<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]4522floating point or vector of floating point type. Not all targets support all
4523types however.
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4524<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4525 declare float @llvm.sqrt.f32(float %Val)
4526 declare double @llvm.sqrt.f64(double %Val)
4527 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
4528 declare fp128 @llvm.sqrt.f128(fp128 %Val)
4529 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4530</pre>
4531
4532<h5>Overview:</h5>
4533
4534<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4535The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4536returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4537<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
4538negative numbers (which allows for better optimization).
4539</p>
4540
4541<h5>Arguments:</h5>
4542
4543<p>
4544The argument and return value are floating point numbers of the same type.
4545</p>
4546
4547<h5>Semantics:</h5>
4548
4549<p>
Dan Gohmand6257fe2007-07-16 14:37:41 +0000[diff] [blame]4550This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4551floating point number.
4552</p>
4553</div>
4554
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4555<!-- _______________________________________________________________________ -->
4556<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4557 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4558</div>
4559
4560<div class="doc_text">
4561
4562<h5>Syntax:</h5>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4563<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]4564floating point or vector of floating point type. Not all targets support all
4565types however.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4566<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]4567 declare float @llvm.powi.f32(float %Val, i32 %power)
4568 declare double @llvm.powi.f64(double %Val, i32 %power)
4569 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
4570 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
4571 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4572</pre>
4573
4574<h5>Overview:</h5>
4575
4576<p>
4577The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
4578specified (positive or negative) power. The order of evaluation of
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4579multiplications is not defined. When a vector of floating point type is
4580used, the second argument remains a scalar integer value.
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4581</p>
4582
4583<h5>Arguments:</h5>
4584
4585<p>
4586The second argument is an integer power, and the first is a value to raise to
4587that power.
4588</p>
4589
4590<h5>Semantics:</h5>
4591
4592<p>
4593This function returns the first value raised to the second power with an
4594unspecified sequence of rounding operations.</p>
4595</div>
4596
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4597<!-- _______________________________________________________________________ -->
4598<div class="doc_subsubsection">
4599 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
4600</div>
4601
4602<div class="doc_text">
4603
4604<h5>Syntax:</h5>
4605<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
4606floating point or vector of floating point type. Not all targets support all
4607types however.
4608<pre>
4609 declare float @llvm.sin.f32(float %Val)
4610 declare double @llvm.sin.f64(double %Val)
4611 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
4612 declare fp128 @llvm.sin.f128(fp128 %Val)
4613 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
4614</pre>
4615
4616<h5>Overview:</h5>
4617
4618<p>
4619The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
4620</p>
4621
4622<h5>Arguments:</h5>
4623
4624<p>
4625The argument and return value are floating point numbers of the same type.
4626</p>
4627
4628<h5>Semantics:</h5>
4629
4630<p>
4631This function returns the sine of the specified operand, returning the
4632same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4633conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4634</div>
4635
4636<!-- _______________________________________________________________________ -->
4637<div class="doc_subsubsection">
4638 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
4639</div>
4640
4641<div class="doc_text">
4642
4643<h5>Syntax:</h5>
4644<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
4645floating point or vector of floating point type. Not all targets support all
4646types however.
4647<pre>
4648 declare float @llvm.cos.f32(float %Val)
4649 declare double @llvm.cos.f64(double %Val)
4650 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
4651 declare fp128 @llvm.cos.f128(fp128 %Val)
4652 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
4653</pre>
4654
4655<h5>Overview:</h5>
4656
4657<p>
4658The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
4659</p>
4660
4661<h5>Arguments:</h5>
4662
4663<p>
4664The argument and return value are floating point numbers of the same type.
4665</p>
4666
4667<h5>Semantics:</h5>
4668
4669<p>
4670This function returns the cosine of the specified operand, returning the
4671same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4672conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4673</div>
4674
4675<!-- _______________________________________________________________________ -->
4676<div class="doc_subsubsection">
4677 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
4678</div>
4679
4680<div class="doc_text">
4681
4682<h5>Syntax:</h5>
4683<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
4684floating point or vector of floating point type. Not all targets support all
4685types however.
4686<pre>
4687 declare float @llvm.pow.f32(float %Val, float %Power)
4688 declare double @llvm.pow.f64(double %Val, double %Power)
4689 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
4690 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
4691 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
4692</pre>
4693
4694<h5>Overview:</h5>
4695
4696<p>
4697The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
4698specified (positive or negative) power.
4699</p>
4700
4701<h5>Arguments:</h5>
4702
4703<p>
4704The second argument is a floating point power, and the first is a value to
4705raise to that power.
4706</p>
4707
4708<h5>Semantics:</h5>
4709
4710<p>
4711This function returns the first value raised to the second power,
4712returning the
4713same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmanba83b7e2007-10-17 18:05:13 +0000[diff] [blame]4714conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]4715</div>
4716
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4717
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4718<!-- ======================================================================= -->
4719<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4720 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4721</div>
4722
4723<div class="doc_text">
4724<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4725LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4726These allow efficient code generation for some algorithms.
4727</p>
4728
4729</div>
4730
4731<!-- _______________________________________________________________________ -->
4732<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4733 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4734</div>
4735
4736<div class="doc_text">
4737
4738<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4739<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4740type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4741<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4742 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
4743 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
4744 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4745</pre>
4746
4747<h5>Overview:</h5>
4748
4749<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]4750The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4751values with an even number of bytes (positive multiple of 16 bits). These are
4752useful for performing operations on data that is not in the target's native
4753byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4754</p>
4755
4756<h5>Semantics:</h5>
4757
4758<p>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4759The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4760and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
4761intrinsic returns an i32 value that has the four bytes of the input i32
4762swapped, 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]4763i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
4764<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4765additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4766</p>
4767
4768</div>
4769
4770<!-- _______________________________________________________________________ -->
4771<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4772 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4773</div>
4774
4775<div class="doc_text">
4776
4777<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4778<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
4779width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4780<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4781 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
4782 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4783 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4784 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
4785 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4786</pre>
4787
4788<h5>Overview:</h5>
4789
4790<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]4791The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
4792value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4793</p>
4794
4795<h5>Arguments:</h5>
4796
4797<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4798The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4799integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4800</p>
4801
4802<h5>Semantics:</h5>
4803
4804<p>
4805The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
4806</p>
4807</div>
4808
4809<!-- _______________________________________________________________________ -->
4810<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4811 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4812</div>
4813
4814<div class="doc_text">
4815
4816<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4817<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
4818integer bit width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4819<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4820 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
4821 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4822 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4823 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
4824 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4825</pre>
4826
4827<h5>Overview:</h5>
4828
4829<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4830The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
4831leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4832</p>
4833
4834<h5>Arguments:</h5>
4835
4836<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4837The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4838integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4839</p>
4840
4841<h5>Semantics:</h5>
4842
4843<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4844The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
4845in 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]4846of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4847</p>
4848</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4849
4850
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4851
4852<!-- _______________________________________________________________________ -->
4853<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4854 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4855</div>
4856
4857<div class="doc_text">
4858
4859<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4860<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
4861integer bit width. Not all targets support all bit widths however.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4862<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4863 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
4864 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4865 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4866 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
4867 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4868</pre>
4869
4870<h5>Overview:</h5>
4871
4872<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4873The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
4874trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4875</p>
4876
4877<h5>Arguments:</h5>
4878
4879<p>
4880The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4881integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4882</p>
4883
4884<h5>Semantics:</h5>
4885
4886<p>
4887The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
4888in a variable. If the src == 0 then the result is the size in bits of the type
4889of src. For example, <tt>llvm.cttz(2) = 1</tt>.
4890</p>
4891</div>
4892
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]4893<!-- _______________________________________________________________________ -->
4894<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4895 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4896</div>
4897
4898<div class="doc_text">
4899
4900<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4901<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4902on any integer bit width.
4903<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4904 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
4905 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4906</pre>
4907
4908<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4909<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4910range of bits from an integer value and returns them in the same bit width as
4911the original value.</p>
4912
4913<h5>Arguments:</h5>
4914<p>The first argument, <tt>%val</tt> and the result may be integer types of
4915any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4916arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4917
4918<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4919<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4920of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
4921<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
4922operates in forward mode.</p>
4923<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
4924right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4925only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
4926<ol>
4927 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
4928 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
4929 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
4930 to determine the number of bits to retain.</li>
4931 <li>A mask of the retained bits is created by shifting a -1 value.</li>
4932 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
4933</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]4934<p>In reverse mode, a similar computation is made except that the bits are
4935returned in the reverse order. So, for example, if <tt>X</tt> has the value
4936<tt>i16 0x0ACF (101011001111)</tt> and we apply
4937<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
4938<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4939</div>
4940
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]4941<div class="doc_subsubsection">
4942 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
4943</div>
4944
4945<div class="doc_text">
4946
4947<h5>Syntax:</h5>
4948<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
4949on any integer bit width.
4950<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]4951 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
4952 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]4953</pre>
4954
4955<h5>Overview:</h5>
4956<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
4957of bits in an integer value with another integer value. It returns the integer
4958with the replaced bits.</p>
4959
4960<h5>Arguments:</h5>
4961<p>The first argument, <tt>%val</tt> and the result may be integer types of
4962any bit width but they must have the same bit width. <tt>%val</tt> is the value
4963whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
4964integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
4965type since they specify only a bit index.</p>
4966
4967<h5>Semantics:</h5>
4968<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
4969of operation: forwards and reverse. If <tt>%lo</tt> is greater than
4970<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
4971operates in forward mode.</p>
4972<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
4973truncating it down to the size of the replacement area or zero extending it
4974up to that size.</p>
4975<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
4976are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
4977in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
4978to the <tt>%hi</tt>th bit.
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]4979<p>In reverse mode, a similar computation is made except that the bits are
4980reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
4981<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]4982<h5>Examples:</h5>
4983<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]4984 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]4985 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
4986 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
4987 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]4988 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]4989</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]4990</div>
4991
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4992<!-- ======================================================================= -->
4993<div class="doc_subsection">
4994 <a name="int_debugger">Debugger Intrinsics</a>
4995</div>
4996
4997<div class="doc_text">
4998<p>
4999The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5000are described in the <a
5001href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5002Debugging</a> document.
5003</p>
5004</div>
5005
5006
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5007<!-- ======================================================================= -->
5008<div class="doc_subsection">
5009 <a name="int_eh">Exception Handling Intrinsics</a>
5010</div>
5011
5012<div class="doc_text">
5013<p> The LLVM exception handling intrinsics (which all start with
5014<tt>llvm.eh.</tt> prefix), are described in the <a
5015href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5016Handling</a> document. </p>
5017</div>
5018
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5019<!-- ======================================================================= -->
5020<div class="doc_subsection">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5021 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5022</div>
5023
5024<div class="doc_text">
5025<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5026 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5027 the <tt>nest</tt> attribute, from a function. The result is a callable
5028 function pointer lacking the nest parameter - the caller does not need
5029 to provide a value for it. Instead, the value to use is stored in
5030 advance in a "trampoline", a block of memory usually allocated
5031 on the stack, which also contains code to splice the nest value into the
5032 argument list. This is used to implement the GCC nested function address
5033 extension.
5034</p>
5035<p>
5036 For example, if the function is
5037 <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]5038 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]5039<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5040 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5041 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5042 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5043 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5044</pre>
Bill Wendling03295ca2007-09-22 09:23:55 +0000[diff] [blame]5045 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5046 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5047</div>
5048
5049<!-- _______________________________________________________________________ -->
5050<div class="doc_subsubsection">
5051 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5052</div>
5053<div class="doc_text">
5054<h5>Syntax:</h5>
5055<pre>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5056declare 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]5057</pre>
5058<h5>Overview:</h5>
5059<p>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5060 This fills the memory pointed to by <tt>tramp</tt> with code
5061 and returns a function pointer suitable for executing it.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5062</p>
5063<h5>Arguments:</h5>
5064<p>
5065 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5066 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5067 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsc00c2ba2007-08-22 23:39:54 +0000[diff] [blame]5068 intrinsic. Note that the size and the alignment are target-specific - LLVM
5069 currently provides no portable way of determining them, so a front-end that
5070 generates this intrinsic needs to have some target-specific knowledge.
5071 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]5072</p>
5073<h5>Semantics:</h5>
5074<p>
5075 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5076 dependent code, turning it into a function. A pointer to this function is
5077 returned, but needs to be bitcast to an
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5078 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]5079 before being called. The new function's signature is the same as that of
5080 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5081 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5082 of pointer type. Calling the new function is equivalent to calling
5083 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5084 missing <tt>nest</tt> argument. If, after calling
5085 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5086 modified, then the effect of any later call to the returned function pointer is
5087 undefined.
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]5088</p>
5089</div>
5090
5091<!-- ======================================================================= -->
5092<div class="doc_subsection">
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5093 <a name="int_general">General Intrinsics</a>
5094</div>
5095
5096<div class="doc_text">
5097<p> This class of intrinsics is designed to be generic and has
5098no specific purpose. </p>
5099</div>
5100
5101<!-- _______________________________________________________________________ -->
5102<div class="doc_subsubsection">
5103 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
5104</div>
5105
5106<div class="doc_text">
5107
5108<h5>Syntax:</h5>
5109<pre>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]5110 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]5111</pre>
5112
5113<h5>Overview:</h5>
5114
5115<p>
5116The '<tt>llvm.var.annotation</tt>' intrinsic
5117</p>
5118
5119<h5>Arguments:</h5>
5120
5121<p>
Tanya Lattnerd2e84422007-06-18 23:42:37 +0000[diff] [blame]5122The first argument is a pointer to a value, the second is a pointer to a
5123global string, the third is a pointer to a global string which is the source
5124file name, and the last argument is the line number.
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]5125</p>
5126
5127<h5>Semantics:</h5>
5128
5129<p>
5130This intrinsic allows annotation of local variables with arbitrary strings.
5131This can be useful for special purpose optimizations that want to look for these
5132 annotations. These have no other defined use, they are ignored by code
5133 generation and optimization.
5134</div>
5135
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5136<!-- _______________________________________________________________________ -->
5137<div class="doc_subsubsection">
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]5138 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5139</div>
5140
5141<div class="doc_text">
5142
5143<h5>Syntax:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5144<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
5145any integer bit width.
5146</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5147<pre>
Tanya Lattnerd3989a82007-09-22 00:03:01 +0000[diff] [blame]5148 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5149 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5150 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5151 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5152 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]5153</pre>
5154
5155<h5>Overview:</h5>
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5156
5157<p>
5158The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5159</p>
5160
5161<h5>Arguments:</h5>
5162
5163<p>
5164The first argument is an integer value (result of some expression),
5165the second is a pointer to a global string, the third is a pointer to a global
5166string which is the source file name, and the last argument is the line number.
Tanya Lattner39cfba62007-09-21 23:56:27 +0000[diff] [blame]5167It returns the value of the first argument.
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]5168</p>
5169
5170<h5>Semantics:</h5>
5171
5172<p>
5173This intrinsic allows annotations to be put on arbitrary expressions
5174with arbitrary strings. This can be useful for special purpose optimizations
5175that want to look for these annotations. These have no other defined use, they
5176are ignored by code generation and optimization.
5177</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]5178
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5179<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5180<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]5181<address>
5182 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
5183 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
5184 <a href="http://validator.w3.org/check/referer"><img
5185 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
5186
5187 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]5188 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]5189 Last modified: $Date$
5190</address>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5191</body>
5192</html>