Gitiles
Code Review Sign In
gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 4a3c9019032d892008f868fa5f9a806dc4b783ce / . / docs / LangRef.html
blob: e8813d2751b2f1e704dd7337b40bcd2abf235a40 [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>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]180 </ol>
181 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]182 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]183 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]184 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]185 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
186 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
187 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]188 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
189 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]190 </ol>
191 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]192 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]193 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]194 </ol>
195 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]196</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]197
198<div class="doc_author">
199 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
200 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]201</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]202
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]203<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]204<div class="doc_section"> <a name="abstract">Abstract </a></div>
205<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]206
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]207<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]208<p>This document is a reference manual for the LLVM assembly language.
209LLVM is an SSA based representation that provides type safety,
210low-level operations, flexibility, and the capability of representing
211'all' high-level languages cleanly. It is the common code
212representation used throughout all phases of the LLVM compilation
213strategy.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]214</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]215
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]216<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]217<div class="doc_section"> <a name="introduction">Introduction</a> </div>
218<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]219
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]220<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]221
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]222<p>The LLVM code representation is designed to be used in three
223different forms: as an in-memory compiler IR, as an on-disk bytecode
224representation (suitable for fast loading by a Just-In-Time compiler),
225and as a human readable assembly language representation. This allows
226LLVM to provide a powerful intermediate representation for efficient
227compiler transformations and analysis, while providing a natural means
228to debug and visualize the transformations. The three different forms
229of LLVM are all equivalent. This document describes the human readable
230representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]231
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]232<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]233while being expressive, typed, and extensible at the same time. It
234aims to be a "universal IR" of sorts, by being at a low enough level
235that high-level ideas may be cleanly mapped to it (similar to how
236microprocessors are "universal IR's", allowing many source languages to
237be mapped to them). By providing type information, LLVM can be used as
238the target of optimizations: for example, through pointer analysis, it
239can be proven that a C automatic variable is never accessed outside of
240the current function... allowing it to be promoted to a simple SSA
241value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]242
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]243</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]244
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]245<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]246<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]247
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]248<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]249
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]250<p>It is important to note that this document describes 'well formed'
251LLVM assembly language. There is a difference between what the parser
252accepts and what is considered 'well formed'. For example, the
253following instruction is syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]254
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]255<div class="doc_code">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]256<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]257%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]258</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]259</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]260
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]261<p>...because the definition of <tt>%x</tt> does not dominate all of
262its uses. The LLVM infrastructure provides a verification pass that may
263be used to verify that an LLVM module is well formed. This pass is
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]264automatically run by the parser after parsing input assembly and by
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]265the optimizer before it outputs bytecode. The violations pointed out
266by the verifier pass indicate bugs in transformation passes or input to
267the parser.</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]268</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]269
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]270<!-- Describe the typesetting conventions here. --> </div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]271
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]272<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]273<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]274<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]275
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]276<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]277
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]278<p>LLVM uses three different forms of identifiers, for different
279purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]280
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]281<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]282 <li>Named values are represented as a string of characters with a '%' prefix.
283 For example, %foo, %DivisionByZero, %a.really.long.identifier. The actual
284 regular expression used is '<tt>%[a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
285 Identifiers which require other characters in their names can be surrounded
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]286 with quotes. In this way, anything except a <tt>&quot;</tt> character can be used
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]287 in a name.</li>
288
289 <li>Unnamed values are represented as an unsigned numeric value with a '%'
290 prefix. For example, %12, %2, %44.</li>
291
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]292 <li>Constants, which are described in a <a href="#constants">section about
293 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]294</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]295
296<p>LLVM requires that values start with a '%' sign for two reasons: Compilers
297don't need to worry about name clashes with reserved words, and the set of
298reserved words may be expanded in the future without penalty. Additionally,
299unnamed identifiers allow a compiler to quickly come up with a temporary
300variable without having to avoid symbol table conflicts.</p>
301
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]302<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]303languages. There are keywords for different opcodes
304('<tt><a href="#i_add">add</a></tt>',
305 '<tt><a href="#i_bitcast">bitcast</a></tt>',
306 '<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]307href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]308and others. These reserved words cannot conflict with variable names, because
309none of them start with a '%' character.</p>
310
311<p>Here is an example of LLVM code to multiply the integer variable
312'<tt>%X</tt>' by 8:</p>
313
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]314<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]315
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]316<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]317<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]318%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]319</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]320</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]321
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]322<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]323
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]324<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]325<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]326%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]327</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]328</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]329
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]330<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]331
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]332<div class="doc_code">
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]333<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]334<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
335<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
336%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]337</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]338</div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]339
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]340<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
341important lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]342
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]343<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]344
345 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
346 line.</li>
347
348 <li>Unnamed temporaries are created when the result of a computation is not
349 assigned to a named value.</li>
350
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]351 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]352
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]353</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]354
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]355<p>...and it also shows a convention that we follow in this document. When
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]356demonstrating instructions, we will follow an instruction with a comment that
357defines the type and name of value produced. Comments are shown in italic
358text.</p>
359
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]360</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]361
362<!-- *********************************************************************** -->
363<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
364<!-- *********************************************************************** -->
365
366<!-- ======================================================================= -->
367<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
368</div>
369
370<div class="doc_text">
371
372<p>LLVM programs are composed of "Module"s, each of which is a
373translation unit of the input programs. Each module consists of
374functions, global variables, and symbol table entries. Modules may be
375combined together with the LLVM linker, which merges function (and
376global variable) definitions, resolves forward declarations, and merges
377symbol table entries. Here is an example of the "hello world" module:</p>
378
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]379<div class="doc_code">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]380<pre><i>; Declare the string constant as a global constant...</i>
381<a href="#identifiers">%.LC0</a> = <a href="#linkage_internal">internal</a> <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]382 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]383
384<i>; External declaration of the puts function</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]385<a href="#functionstructure">declare</a> i32 %puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]386
387<i>; Definition of main function</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]388define i32 %main() { <i>; i32()* </i>
389 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]390 %cast210 = <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]391 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]392
393 <i>; Call puts function to write out the string to stdout...</i>
394 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]395 href="#i_call">call</a> i32 %puts(i8 * %cast210) <i>; i32</i>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]396 <a
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]397 href="#i_ret">ret</a> i32 0<br>}<br>
398</pre>
399</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]400
401<p>This example is made up of a <a href="#globalvars">global variable</a>
402named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
403function, and a <a href="#functionstructure">function definition</a>
404for "<tt>main</tt>".</p>
405
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]406<p>In general, a module is made up of a list of global values,
407where both functions and global variables are global values. Global values are
408represented by a pointer to a memory location (in this case, a pointer to an
409array of char, and a pointer to a function), and have one of the following <a
410href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]411
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]412</div>
413
414<!-- ======================================================================= -->
415<div class="doc_subsection">
416 <a name="linkage">Linkage Types</a>
417</div>
418
419<div class="doc_text">
420
421<p>
422All Global Variables and Functions have one of the following types of linkage:
423</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]424
425<dl>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]426
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]427 <dt><tt><b><a name="linkage_internal">internal</a></b></tt> </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]428
429 <dd>Global values with internal linkage are only directly accessible by
430 objects in the current module. In particular, linking code into a module with
431 an internal global value may cause the internal to be renamed as necessary to
432 avoid collisions. Because the symbol is internal to the module, all
433 references can be updated. This corresponds to the notion of the
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]434 '<tt>static</tt>' keyword in C.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]435 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]436
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]437 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]438
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]439 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
440 the same name when linkage occurs. This is typically used to implement
441 inline functions, templates, or other code which must be generated in each
442 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
443 allowed to be discarded.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]444 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]445
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]446 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]447
448 <dd>"<tt>weak</tt>" linkage is exactly the same as <tt>linkonce</tt> linkage,
449 except that unreferenced <tt>weak</tt> globals may not be discarded. This is
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]450 used for globals that may be emitted in multiple translation units, but that
451 are not guaranteed to be emitted into every translation unit that uses them.
452 One example of this are common globals in C, such as "<tt>int X;</tt>" at
453 global scope.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]454 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]455
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]456 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]457
458 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
459 pointer to array type. When two global variables with appending linkage are
460 linked together, the two global arrays are appended together. This is the
461 LLVM, typesafe, equivalent of having the system linker append together
462 "sections" with identical names when .o files are linked.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]463 </dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]464
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]465 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
466 <dd>The semantics of this linkage follow the ELF model: the symbol is weak
467 until linked, if not linked, the symbol becomes null instead of being an
468 undefined reference.
469 </dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]470
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]471 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]472
473 <dd>If none of the above identifiers are used, the global is externally
474 visible, meaning that it participates in linkage and can be used to resolve
475 external symbol references.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]476 </dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]477</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]478
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]479 <p>
480 The next two types of linkage are targeted for Microsoft Windows platform
481 only. They are designed to support importing (exporting) symbols from (to)
482 DLLs.
483 </p>
484
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]485 <dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]486 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
487
488 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
489 or variable via a global pointer to a pointer that is set up by the DLL
490 exporting the symbol. On Microsoft Windows targets, the pointer name is
491 formed by combining <code>_imp__</code> and the function or variable name.
492 </dd>
493
494 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
495
496 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
497 pointer to a pointer in a DLL, so that it can be referenced with the
498 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
499 name is formed by combining <code>_imp__</code> and the function or variable
500 name.
501 </dd>
502
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]503</dl>
504
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]505<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]506variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
507variable and was linked with this one, one of the two would be renamed,
508preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
509external (i.e., lacking any linkage declarations), they are accessible
Reid Spencerac8d2762007-01-05 00:59:10 +0000[diff] [blame]510outside of the current module.</p>
511<p>It is illegal for a function <i>declaration</i>
512to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]513or <tt>extern_weak</tt>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]514<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
515linkages.
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]516</div>
517
518<!-- ======================================================================= -->
519<div class="doc_subsection">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]520 <a name="callingconv">Calling Conventions</a>
521</div>
522
523<div class="doc_text">
524
525<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
526and <a href="#i_invoke">invokes</a> can all have an optional calling convention
527specified for the call. The calling convention of any pair of dynamic
528caller/callee must match, or the behavior of the program is undefined. The
529following calling conventions are supported by LLVM, and more may be added in
530the future:</p>
531
532<dl>
533 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
534
535 <dd>This calling convention (the default if no other calling convention is
536 specified) matches the target C calling conventions. This calling convention
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]537 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencerc28d2bc2006-12-31 21:30:18 +0000[diff] [blame]538 prototype and implemented declaration of the function (as does normal C).
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]539 </dd>
540
541 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
542
543 <dd>This calling convention attempts to make calls as fast as possible
544 (e.g. by passing things in registers). This calling convention allows the
545 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner8cdc5bc2005-05-06 23:08:23 +0000[diff] [blame]546 without having to conform to an externally specified ABI. Implementations of
547 this convention should allow arbitrary tail call optimization to be supported.
548 This calling convention does not support varargs and requires the prototype of
549 all callees to exactly match the prototype of the function definition.
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]550 </dd>
551
552 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
553
554 <dd>This calling convention attempts to make code in the caller as efficient
555 as possible under the assumption that the call is not commonly executed. As
556 such, these calls often preserve all registers so that the call does not break
557 any live ranges in the caller side. This calling convention does not support
558 varargs and requires the prototype of all callees to exactly match the
559 prototype of the function definition.
560 </dd>
561
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]562 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]563
564 <dd>Any calling convention may be specified by number, allowing
565 target-specific calling conventions to be used. Target specific calling
566 conventions start at 64.
567 </dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]568</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]569
570<p>More calling conventions can be added/defined on an as-needed basis, to
571support pascal conventions or any other well-known target-independent
572convention.</p>
573
574</div>
575
576<!-- ======================================================================= -->
577<div class="doc_subsection">
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]578 <a name="visibility">Visibility Styles</a>
579</div>
580
581<div class="doc_text">
582
583<p>
584All Global Variables and Functions have one of the following visibility styles:
585</p>
586
587<dl>
588 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
589
590 <dd>On ELF, default visibility means that the declaration is visible to other
591 modules and, in shared libraries, means that the declared entity may be
592 overridden. On Darwin, default visibility means that the declaration is
593 visible to other modules. Default visibility corresponds to "external
594 linkage" in the language.
595 </dd>
596
597 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
598
599 <dd>Two declarations of an object with hidden visibility refer to the same
600 object if they are in the same shared object. Usually, hidden visibility
601 indicates that the symbol will not be placed into the dynamic symbol table,
602 so no other module (executable or shared library) can reference it
603 directly.
604 </dd>
605
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]606 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
607
608 <dd>On ELF, protected visibility indicates that the symbol will be placed in
609 the dynamic symbol table, but that references within the defining module will
610 bind to the local symbol. That is, the symbol cannot be overridden by another
611 module.
612 </dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]613</dl>
614
615</div>
616
617<!-- ======================================================================= -->
618<div class="doc_subsection">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]619 <a name="globalvars">Global Variables</a>
620</div>
621
622<div class="doc_text">
623
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]624<p>Global variables define regions of memory allocated at compilation time
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]625instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]626an explicit section to be placed in, and may have an optional explicit alignment
627specified. A variable may be defined as "thread_local", which means that it
628will not be shared by threads (each thread will have a separated copy of the
629variable). A variable may be defined as a global "constant," which indicates
630that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]631optimization, allowing the global data to be placed in the read-only section of
632an executable, etc). Note that variables that need runtime initialization
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]633cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]634
635<p>
636LLVM explicitly allows <em>declarations</em> of global variables to be marked
637constant, even if the final definition of the global is not. This capability
638can be used to enable slightly better optimization of the program, but requires
639the language definition to guarantee that optimizations based on the
640'constantness' are valid for the translation units that do not include the
641definition.
642</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]643
644<p>As SSA values, global variables define pointer values that are in
645scope (i.e. they dominate) all basic blocks in the program. Global
646variables always define a pointer to their "content" type because they
647describe a region of memory, and all memory objects in LLVM are
648accessed through pointers.</p>
649
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]650<p>LLVM allows an explicit section to be specified for globals. If the target
651supports it, it will emit globals to the section specified.</p>
652
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]653<p>An explicit alignment may be specified for a global. If not present, or if
654the alignment is set to zero, the alignment of the global is set by the target
655to whatever it feels convenient. If an explicit alignment is specified, the
656global is forced to have at least that much alignment. All alignments must be
657a power of 2.</p>
658
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]659<p>For example, the following defines a global with an initializer, section,
660 and alignment:</p>
661
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]662<div class="doc_code">
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]663<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]664%G = constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]665</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]666</div>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]667
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]668</div>
669
670
671<!-- ======================================================================= -->
672<div class="doc_subsection">
673 <a name="functionstructure">Functions</a>
674</div>
675
676<div class="doc_text">
677
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]678<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
679an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]680<a href="#visibility">visibility style</a>, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]681<a href="#callingconv">calling convention</a>, a return type, an optional
682<a href="#paramattrs">parameter attribute</a> for the return type, a function
683name, a (possibly empty) argument list (each with optional
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]684<a href="#paramattrs">parameter attributes</a>), an optional section, an
685optional alignment, an opening curly brace, a list of basic blocks, and a
686closing curly brace.
687
688LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
689optional <a href="#linkage">linkage type</a>, an optional
690<a href="#visibility">visibility style</a>, an optional
691<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]692<a href="#paramattrs">parameter attribute</a> for the return type, a function
693name, a possibly empty list of arguments, and an optional alignment.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]694
695<p>A function definition contains a list of basic blocks, forming the CFG for
696the function. Each basic block may optionally start with a label (giving the
697basic block a symbol table entry), contains a list of instructions, and ends
698with a <a href="#terminators">terminator</a> instruction (such as a branch or
699function return).</p>
700
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame^]701<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]702executed on entrance to the function, and it is not allowed to have predecessor
703basic blocks (i.e. there can not be any branches to the entry block of a
704function). Because the block can have no predecessors, it also cannot have any
705<a href="#i_phi">PHI nodes</a>.</p>
706
707<p>LLVM functions are identified by their name and type signature. Hence, two
708functions with the same name but different parameter lists or return values are
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]709considered different functions, and LLVM will resolve references to each
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]710appropriately.</p>
711
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]712<p>LLVM allows an explicit section to be specified for functions. If the target
713supports it, it will emit functions to the section specified.</p>
714
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]715<p>An explicit alignment may be specified for a function. If not present, or if
716the alignment is set to zero, the alignment of the function is set by the target
717to whatever it feels convenient. If an explicit alignment is specified, the
718function is forced to have at least that much alignment. All alignments must be
719a power of 2.</p>
720
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]721</div>
722
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]723
724<!-- ======================================================================= -->
725<div class="doc_subsection">
726 <a name="aliasstructure">Aliases</a>
727</div>
728<div class="doc_text">
729 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikova80e1182007-04-28 13:45:00 +0000[diff] [blame]730 function or global variable or bitcast of global value). Aliases may have an
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]731 optional <a href="#linkage">linkage type</a>, and an
732 optional <a href="#visibility">visibility style</a>.</p>
733
734 <h5>Syntax:</h5>
735
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]736<div class="doc_code">
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]737<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]738@&lt;Name&gt; = [Linkage] [Visibility] alias &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]739</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]740</div>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]741
742</div>
743
744
745
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]746<!-- ======================================================================= -->
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]747<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
748<div class="doc_text">
749 <p>The return type and each parameter of a function type may have a set of
750 <i>parameter attributes</i> associated with them. Parameter attributes are
751 used to communicate additional information about the result or parameters of
752 a function. Parameter attributes are considered to be part of the function
753 type so two functions types that differ only by the parameter attributes
754 are different function types.</p>
755
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]756 <p>Parameter attributes are simple keywords that follow the type specified. If
757 multiple parameter attributes are needed, they are space separated. For
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]758 example:</p>
759
760<div class="doc_code">
761<pre>
762%someFunc = i16 (i8 sext %someParam) zext
763%someFunc = i16 (i8 zext %someParam) zext
764</pre>
765</div>
766
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]767 <p>Note that the two function types above are unique because the parameter has
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]768 a different attribute (sext in the first one, zext in the second). Also note
769 that the attribute for the function result (zext) comes immediately after the
770 argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]771
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]772 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]773 <dl>
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]774 <dt><tt>zext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]775 <dd>This indicates that the parameter should be zero extended just before
776 a call to this function.</dd>
Reid Spencer950e9f82007-01-15 18:27:39 +0000[diff] [blame]777 <dt><tt>sext</tt></dt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]778 <dd>This indicates that the parameter should be sign extended just before
779 a call to this function.</dd>
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]780 <dt><tt>inreg</tt></dt>
781 <dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000[diff] [blame]782 possible) during assembling function call. Support for this attribute is
783 target-specific</dd>
Anton Korobeynikov34d6dea2007-01-28 14:30:45 +0000[diff] [blame]784 <dt><tt>sret</tt></dt>
Anton Korobeynikov66a8c8c2007-01-28 15:27:21 +0000[diff] [blame]785 <dd>This indicates that the parameter specifies the address of a structure
Reid Spencer67606122007-03-22 02:02:11 +0000[diff] [blame]786 that is the return value of the function in the source program.</dd>
Zhou Shengfebca342007-06-05 05:28:26 +0000[diff] [blame]787 <dt><tt>noalias</tt></dt>
788 <dd>This indicates that the parameter not alias any other object or any
789 other "noalias" objects during the function call.
Reid Spencer2dc52012007-03-22 02:18:56 +0000[diff] [blame]790 <dt><tt>noreturn</tt></dt>
791 <dd>This function attribute indicates that the function never returns. This
792 indicates to LLVM that every call to this function should be treated as if
793 an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Reid Spencer67606122007-03-22 02:02:11 +0000[diff] [blame]794 <dt><tt>nounwind</tt></dt>
795 <dd>This function attribute indicates that the function type does not use
796 the unwind instruction and does not allow stack unwinding to propagate
797 through it.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]798 </dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]799
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]800</div>
801
802<!-- ======================================================================= -->
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]803<div class="doc_subsection">
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]804 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]805</div>
806
807<div class="doc_text">
808<p>
809Modules may contain "module-level inline asm" blocks, which corresponds to the
810GCC "file scope inline asm" blocks. These blocks are internally concatenated by
811LLVM and treated as a single unit, but may be separated in the .ll file if
812desired. The syntax is very simple:
813</p>
814
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]815<div class="doc_code">
816<pre>
817module asm "inline asm code goes here"
818module asm "more can go here"
819</pre>
820</div>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]821
822<p>The strings can contain any character by escaping non-printable characters.
823 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
824 for the number.
825</p>
826
827<p>
828 The inline asm code is simply printed to the machine code .s file when
829 assembly code is generated.
830</p>
831</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]832
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]833<!-- ======================================================================= -->
834<div class="doc_subsection">
835 <a name="datalayout">Data Layout</a>
836</div>
837
838<div class="doc_text">
839<p>A module may specify a target specific data layout string that specifies how
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]840data is to be laid out in memory. The syntax for the data layout is simply:</p>
841<pre> target datalayout = "<i>layout specification</i>"</pre>
842<p>The <i>layout specification</i> consists of a list of specifications
843separated by the minus sign character ('-'). Each specification starts with a
844letter and may include other information after the letter to define some
845aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]846<dl>
847 <dt><tt>E</tt></dt>
848 <dd>Specifies that the target lays out data in big-endian form. That is, the
849 bits with the most significance have the lowest address location.</dd>
850 <dt><tt>e</tt></dt>
851 <dd>Specifies that hte target lays out data in little-endian form. That is,
852 the bits with the least significance have the lowest address location.</dd>
853 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
854 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
855 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
856 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
857 too.</dd>
858 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
859 <dd>This specifies the alignment for an integer type of a given bit
860 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
861 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
862 <dd>This specifies the alignment for a vector type of a given bit
863 <i>size</i>.</dd>
864 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
865 <dd>This specifies the alignment for a floating point type of a given bit
866 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
867 (double).</dd>
868 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
869 <dd>This specifies the alignment for an aggregate type of a given bit
870 <i>size</i>.</dd>
871</dl>
872<p>When constructing the data layout for a given target, LLVM starts with a
873default set of specifications which are then (possibly) overriden by the
874specifications in the <tt>datalayout</tt> keyword. The default specifications
875are given in this list:</p>
876<ul>
877 <li><tt>E</tt> - big endian</li>
878 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
879 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
880 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
881 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
882 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
883 <li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
884 alignment of 64-bits</li>
885 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
886 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
887 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
888 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
889 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
890</ul>
891<p>When llvm is determining the alignment for a given type, it uses the
892following rules:
893<ol>
894 <li>If the type sought is an exact match for one of the specifications, that
895 specification is used.</li>
896 <li>If no match is found, and the type sought is an integer type, then the
897 smallest integer type that is larger than the bitwidth of the sought type is
898 used. If none of the specifications are larger than the bitwidth then the the
899 largest integer type is used. For example, given the default specifications
900 above, the i7 type will use the alignment of i8 (next largest) while both
901 i65 and i256 will use the alignment of i64 (largest specified).</li>
902 <li>If no match is found, and the type sought is a vector type, then the
903 largest vector type that is smaller than the sought vector type will be used
904 as a fall back. This happens because <128 x double> can be implemented in
905 terms of 64 <2 x double>, for example.</li>
906</ol>
907</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]908
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]909<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]910<div class="doc_section"> <a name="typesystem">Type System</a> </div>
911<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]912
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]913<div class="doc_text">
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]914
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]915<p>The LLVM type system is one of the most important features of the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]916intermediate representation. Being typed enables a number of
917optimizations to be performed on the IR directly, without having to do
918extra analyses on the side before the transformation. A strong type
919system makes it easier to read the generated code and enables novel
920analyses and transformations that are not feasible to perform on normal
921three address code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]922
923</div>
924
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]925<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]926<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]927<div class="doc_text">
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]928<p>The primitive types are the fundamental building blocks of the LLVM
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]929system. The current set of primitive types is as follows:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]930
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]931<table class="layout">
932 <tr class="layout">
933 <td class="left">
934 <table>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]935 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]936 <tr><th>Type</th><th>Description</th></tr>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]937 <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]938 <tr><td><tt>label</tt></td><td>Branch destination</td></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]939 </tbody>
940 </table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]941 </td>
942 <td class="right">
943 <table>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]944 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]945 <tr><th>Type</th><th>Description</th></tr>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]946 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]947 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]948 </tbody>
949 </table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]950 </td>
951 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]952</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]953</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]954
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]955<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]956<div class="doc_subsubsection"> <a name="t_classifications">Type
957Classifications</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]958<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]959<p>These different primitive types fall into a few useful
960classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]961
962<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]963 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]964 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]965 <tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]966 <td><a name="t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]967 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]968 </tr>
969 <tr>
970 <td><a name="t_floating">floating point</a></td>
971 <td><tt>float, double</tt></td>
972 </tr>
973 <tr>
974 <td><a name="t_firstclass">first class</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]975 <td><tt>i1, ..., float, double, <br/>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]976 <a href="#t_pointer">pointer</a>,<a href="#t_vector">vector</a></tt>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]977 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]978 </tr>
979 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]980</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]981
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]982<p>The <a href="#t_firstclass">first class</a> types are perhaps the
983most important. Values of these types are the only ones which can be
984produced by instructions, passed as arguments, or used as operands to
985instructions. This means that all structures and arrays must be
986manipulated either by pointer or by component.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]987</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]988
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]989<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]990<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]991
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]992<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]993
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]994<p>The real power in LLVM comes from the derived types in the system.
995This is what allows a programmer to represent arrays, functions,
996pointers, and other useful types. Note that these derived types may be
997recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]998
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]999</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1000
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1001<!-- _______________________________________________________________________ -->
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1002<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1003
1004<div class="doc_text">
1005
1006<h5>Overview:</h5>
1007<p>The integer type is a very simple derived type that simply specifies an
1008arbitrary bit width for the integer type desired. Any bit width from 1 bit to
10092^23-1 (about 8 million) can be specified.</p>
1010
1011<h5>Syntax:</h5>
1012
1013<pre>
1014 iN
1015</pre>
1016
1017<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1018value.</p>
1019
1020<h5>Examples:</h5>
1021<table class="layout">
1022 <tr class="layout">
1023 <td class="left">
1024 <tt>i1</tt><br/>
1025 <tt>i4</tt><br/>
1026 <tt>i8</tt><br/>
1027 <tt>i16</tt><br/>
1028 <tt>i32</tt><br/>
1029 <tt>i42</tt><br/>
1030 <tt>i64</tt><br/>
1031 <tt>i1942652</tt><br/>
1032 </td>
1033 <td class="left">
1034 A boolean integer of 1 bit<br/>
1035 A nibble sized integer of 4 bits.<br/>
1036 A byte sized integer of 8 bits.<br/>
1037 A half word sized integer of 16 bits.<br/>
1038 A word sized integer of 32 bits.<br/>
1039 An integer whose bit width is the answer. <br/>
1040 A double word sized integer of 64 bits.<br/>
1041 A really big integer of over 1 million bits.<br/>
1042 </td>
1043 </tr>
1044</table>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1045</div>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1046
1047<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1048<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1049
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1050<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1051
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1052<h5>Overview:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1053
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1054<p>The array type is a very simple derived type that arranges elements
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1055sequentially in memory. The array type requires a size (number of
1056elements) and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1057
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1058<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1059
1060<pre>
1061 [&lt;# elements&gt; x &lt;elementtype&gt;]
1062</pre>
1063
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1064<p>The number of elements is a constant integer value; elementtype may
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1065be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1066
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1067<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1068<table class="layout">
1069 <tr class="layout">
1070 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1071 <tt>[40 x i32 ]</tt><br/>
1072 <tt>[41 x i32 ]</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1073 <tt>[40 x i8]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1074 </td>
1075 <td class="left">
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1076 Array of 40 32-bit integer values.<br/>
1077 Array of 41 32-bit integer values.<br/>
1078 Array of 40 8-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1079 </td>
1080 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1081</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1082<p>Here are some examples of multidimensional arrays:</p>
1083<table class="layout">
1084 <tr class="layout">
1085 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1086 <tt>[3 x [4 x i32]]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1087 <tt>[12 x [10 x float]]</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1088 <tt>[2 x [3 x [4 x i16]]]</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1089 </td>
1090 <td class="left">
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1091 3x4 array of 32-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1092 12x10 array of single precision floating point values.<br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1093 2x3x4 array of 16-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1094 </td>
1095 </tr>
1096</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1097
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1098<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1099length array. Normally, accesses past the end of an array are undefined in
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1100LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1101As a special case, however, zero length arrays are recognized to be variable
1102length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1103type "{ i32, [0 x float]}", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1104
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1105</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1106
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1107<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1108<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1109<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1110<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1111<p>The function type can be thought of as a function signature. It
1112consists of a return type and a list of formal parameter types.
John Criswell009900b2003-11-25 21:45:46 +0000[diff] [blame]1113Function types are usually used to build virtual function tables
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1114(which are structures of pointers to functions), for indirect function
1115calls, and when defining a function.</p>
John Criswell009900b2003-11-25 21:45:46 +0000[diff] [blame]1116<p>
1117The return type of a function type cannot be an aggregate type.
1118</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1119<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1120<pre> &lt;returntype&gt; (&lt;parameter list&gt;)<br></pre>
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1121<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]1122specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1123which indicates that the function takes a variable number of arguments.
1124Variable argument functions can access their arguments with the <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1125 href="#int_varargs">variable argument handling intrinsic</a> functions.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1126<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1127<table class="layout">
1128 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1129 <td class="left"><tt>i32 (i32)</tt></td>
1130 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1131 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1132 </tr><tr class="layout">
Reid Spencer7bf214d2007-01-15 18:28:34 +0000[diff] [blame]1133 <td class="left"><tt>float&nbsp;(i16&nbsp;sext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1134 </tt></td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1135 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1136 an <tt>i16</tt> that should be sign extended and a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1137 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1138 <tt>float</tt>.
1139 </td>
1140 </tr><tr class="layout">
1141 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1142 <td class="left">A vararg function that takes at least one
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1143 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1144 which returns an integer. This is the signature for <tt>printf</tt> in
1145 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1146 </td>
1147 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1148</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1149
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1150</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1151<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1152<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1153<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1154<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1155<p>The structure type is used to represent a collection of data members
1156together in memory. The packing of the field types is defined to match
1157the ABI of the underlying processor. The elements of a structure may
1158be any type that has a size.</p>
1159<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1160and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1161field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1162instruction.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1163<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1164<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1165<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1166<table class="layout">
1167 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1168 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1169 <td class="left">A triple of three <tt>i32</tt> values</td>
1170 </tr><tr class="layout">
1171 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1172 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1173 second element is a <a href="#t_pointer">pointer</a> to a
1174 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1175 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1176 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1177</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1178</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1179
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1180<!-- _______________________________________________________________________ -->
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1181<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1182</div>
1183<div class="doc_text">
1184<h5>Overview:</h5>
1185<p>The packed structure type is used to represent a collection of data members
1186together in memory. There is no padding between fields. Further, the alignment
1187of a packed structure is 1 byte. The elements of a packed structure may
1188be any type that has a size.</p>
1189<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1190and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1191field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1192instruction.</p>
1193<h5>Syntax:</h5>
1194<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1195<h5>Examples:</h5>
1196<table class="layout">
1197 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1198 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1199 <td class="left">A triple of three <tt>i32</tt> values</td>
1200 </tr><tr class="layout">
1201 <td class="left"><tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}&nbsp;&gt;</tt></td>
1202 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1203 second element is a <a href="#t_pointer">pointer</a> to a
1204 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1205 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1206 </tr>
1207</table>
1208</div>
1209
1210<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1211<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1212<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1213<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1214<p>As in many languages, the pointer type represents a pointer or
1215reference to another object, which must live in memory.</p>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1216<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1217<pre> &lt;type&gt; *<br></pre>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1218<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1219<table class="layout">
1220 <tr class="layout">
1221 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1222 <tt>[4x i32]*</tt><br/>
1223 <tt>i32 (i32 *) *</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1224 </td>
1225 <td class="left">
1226 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]1227 four <tt>i32</tt> values<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1228 A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1229 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
1230 <tt>i32</tt>.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1231 </td>
1232 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1233</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1234</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1235
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1236<!-- _______________________________________________________________________ -->
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1237<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1238<div class="doc_text">
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1239
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1240<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1241
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1242<p>A vector type is a simple derived type that represents a vector
1243of elements. Vector types are used when multiple primitive data
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1244are operated in parallel using a single instruction (SIMD).
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1245A vector type requires a size (number of
Chris Lattnerb8d172f2005-11-10 01:44:22 +0000[diff] [blame]1246elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1247of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1248considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1249
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1250<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1251
1252<pre>
1253 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1254</pre>
1255
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1256<p>The number of elements is a constant integer value; elementtype may
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]1257be any integer or floating point type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1258
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1259<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1260
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1261<table class="layout">
1262 <tr class="layout">
1263 <td class="left">
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1264 <tt>&lt;4 x i32&gt;</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1265 <tt>&lt;8 x float&gt;</tt><br/>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1266 <tt>&lt;2 x i64&gt;</tt><br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1267 </td>
1268 <td class="left">
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1269 Vector of 4 32-bit integer values.<br/>
1270 Vector of 8 floating-point values.<br/>
1271 Vector of 2 64-bit integer values.<br/>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1272 </td>
1273 </tr>
1274</table>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1275</div>
1276
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1277<!-- _______________________________________________________________________ -->
1278<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1279<div class="doc_text">
1280
1281<h5>Overview:</h5>
1282
1283<p>Opaque types are used to represent unknown types in the system. This
1284corresponds (for example) to the C notion of a foward declared structure type.
1285In LLVM, opaque types can eventually be resolved to any type (not just a
1286structure type).</p>
1287
1288<h5>Syntax:</h5>
1289
1290<pre>
1291 opaque
1292</pre>
1293
1294<h5>Examples:</h5>
1295
1296<table class="layout">
1297 <tr class="layout">
1298 <td class="left">
1299 <tt>opaque</tt>
1300 </td>
1301 <td class="left">
1302 An opaque type.<br/>
1303 </td>
1304 </tr>
1305</table>
1306</div>
1307
1308
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1309<!-- *********************************************************************** -->
1310<div class="doc_section"> <a name="constants">Constants</a> </div>
1311<!-- *********************************************************************** -->
1312
1313<div class="doc_text">
1314
1315<p>LLVM has several different basic types of constants. This section describes
1316them all and their syntax.</p>
1317
1318</div>
1319
1320<!-- ======================================================================= -->
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1321<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1322
1323<div class="doc_text">
1324
1325<dl>
1326 <dt><b>Boolean constants</b></dt>
1327
1328 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1329 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1330 </dd>
1331
1332 <dt><b>Integer constants</b></dt>
1333
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1334 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1335 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1336 integer types.
1337 </dd>
1338
1339 <dt><b>Floating point constants</b></dt>
1340
1341 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1342 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1343 notation (see below). Floating point constants must have a <a
1344 href="#t_floating">floating point</a> type. </dd>
1345
1346 <dt><b>Null pointer constants</b></dt>
1347
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1348 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1349 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1350
1351</dl>
1352
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1353<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1354of floating point constants. For example, the form '<tt>double
13550x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
13564.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]1357(and the only time that they are generated by the disassembler) is when a
1358floating point constant must be emitted but it cannot be represented as a
1359decimal floating point number. For example, NaN's, infinities, and other
1360special values are represented in their IEEE hexadecimal format so that
1361assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1362
1363</div>
1364
1365<!-- ======================================================================= -->
1366<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1367</div>
1368
1369<div class="doc_text">
Chris Lattnerd4f6b172005-03-07 22:13:59 +0000[diff] [blame]1370<p>Aggregate constants arise from aggregation of simple constants
1371and smaller aggregate constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1372
1373<dl>
1374 <dt><b>Structure constants</b></dt>
1375
1376 <dd>Structure constants are represented with notation similar to structure
1377 type definitions (a comma separated list of elements, surrounded by braces
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1378 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* %G }</tt>",
1379 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]1380 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1381 types of elements must match those specified by the type.
1382 </dd>
1383
1384 <dt><b>Array constants</b></dt>
1385
1386 <dd>Array constants are represented with notation similar to array type
1387 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1388 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1389 constants must have <a href="#t_array">array type</a>, and the number and
1390 types of elements must match those specified by the type.
1391 </dd>
1392
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1393 <dt><b>Vector constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1394
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1395 <dd>Vector constants are represented with notation similar to vector type
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1396 definitions (a comma separated list of elements, surrounded by
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1397 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]1398 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1399 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1400 match those specified by the type.
1401 </dd>
1402
1403 <dt><b>Zero initialization</b></dt>
1404
1405 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1406 value to zero of <em>any</em> type, including scalar and aggregate types.
1407 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]1408 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1409 initializers.
1410 </dd>
1411</dl>
1412
1413</div>
1414
1415<!-- ======================================================================= -->
1416<div class="doc_subsection">
1417 <a name="globalconstants">Global Variable and Function Addresses</a>
1418</div>
1419
1420<div class="doc_text">
1421
1422<p>The addresses of <a href="#globalvars">global variables</a> and <a
1423href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1424constants. These constants are explicitly referenced when the <a
1425href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1426href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1427file:</p>
1428
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1429<div class="doc_code">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1430<pre>
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]1431@X = global i32 17
1432@Y = global i32 42
1433@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1434</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1435</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1436
1437</div>
1438
1439<!-- ======================================================================= -->
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1440<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1441<div class="doc_text">
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1442 <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]1443 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1444 a constant is permitted.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1445
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1446 <p>Undefined values indicate to the compiler that the program is well defined
1447 no matter what value is used, giving the compiler more freedom to optimize.
1448 </p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1449</div>
1450
1451<!-- ======================================================================= -->
1452<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1453</div>
1454
1455<div class="doc_text">
1456
1457<p>Constant expressions are used to allow expressions involving other constants
1458to be used as constants. Constant expressions may be of any <a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1459href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1460that does not have side effects (e.g. load and call are not supported). The
1461following is the syntax for constant expressions:</p>
1462
1463<dl>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1464 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1465 <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]1466 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1467
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1468 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1469 <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]1470 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]1471
1472 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1473 <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]1474 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]1475
1476 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1477 <dd>Truncate a floating point constant to another floating point type. The
1478 size of CST must be larger than the size of TYPE. Both types must be
1479 floating point.</dd>
1480
1481 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1482 <dd>Floating point extend a constant to another type. The size of CST must be
1483 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1484
1485 <dt><b><tt>fp2uint ( CST to TYPE )</tt></b></dt>
1486 <dd>Convert a floating point constant to the corresponding unsigned integer
1487 constant. TYPE must be an integer type. CST must be floating point. If the
1488 value won't fit in the integer type, the results are undefined.</dd>
1489
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1490 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1491 <dd>Convert a floating point constant to the corresponding signed integer
1492 constant. TYPE must be an integer type. CST must be floating point. If the
1493 value won't fit in the integer type, the results are undefined.</dd>
1494
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1495 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1496 <dd>Convert an unsigned integer constant to the corresponding floating point
1497 constant. TYPE must be floating point. CST must be of integer type. If the
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]1498 value won't fit in the floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1499
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]1500 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1501 <dd>Convert a signed integer constant to the corresponding floating point
1502 constant. TYPE must be floating point. CST must be of integer type. If the
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]1503 value won't fit in the floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1504
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]1505 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1506 <dd>Convert a pointer typed constant to the corresponding integer constant
1507 TYPE must be an integer type. CST must be of pointer type. The CST value is
1508 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1509
1510 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1511 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1512 pointer type. CST must be of integer type. The CST value is zero extended,
1513 truncated, or unchanged to make it fit in a pointer size. This one is
1514 <i>really</i> dangerous!</dd>
1515
1516 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1517 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1518 identical (same number of bits). The conversion is done as if the CST value
1519 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]1520 with this operator, just the type. This can be used for conversion of
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1521 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]1522 pointers it is only valid to cast to another pointer type.
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]1523 </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1524
1525 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1526
1527 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1528 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1529 instruction, the index list may have zero or more indexes, which are required
1530 to make sense for the type of "CSTPTR".</dd>
1531
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1532 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1533
1534 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1535 constants.</dd>
1536
1537 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1538 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1539
1540 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1541 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]1542
1543 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1544
1545 <dd>Perform the <a href="#i_extractelement">extractelement
1546 operation</a> on constants.
1547
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1548 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1549
1550 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1551 operation</a> on constants.</dd>
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]1552
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1553
1554 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1555
1556 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]1557 operation</a> on constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]1558
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1559 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1560
Reid Spencer2dc45b82004-12-09 18:13:12 +0000[diff] [blame]1561 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1562 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1563 binary</a> operations. The constraints on operands are the same as those for
1564 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1565 values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1566</dl>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1567</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]1568
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1569<!-- *********************************************************************** -->
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1570<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1571<!-- *********************************************************************** -->
1572
1573<!-- ======================================================================= -->
1574<div class="doc_subsection">
1575<a name="inlineasm">Inline Assembler Expressions</a>
1576</div>
1577
1578<div class="doc_text">
1579
1580<p>
1581LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1582Module-Level Inline Assembly</a>) through the use of a special value. This
1583value represents the inline assembler as a string (containing the instructions
1584to emit), a list of operand constraints (stored as a string), and a flag that
1585indicates whether or not the inline asm expression has side effects. An example
1586inline assembler expression is:
1587</p>
1588
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1589<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1590<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1591i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1592</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1593</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1594
1595<p>
1596Inline assembler expressions may <b>only</b> be used as the callee operand of
1597a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1598</p>
1599
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1600<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1601<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1602%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]1603</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1604</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1605
1606<p>
1607Inline asms with side effects not visible in the constraint list must be marked
1608as having side effects. This is done through the use of the
1609'<tt>sideeffect</tt>' keyword, like so:
1610</p>
1611
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1612<div class="doc_code">
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1613<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1614call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1615</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1616</div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]1617
1618<p>TODO: The format of the asm and constraints string still need to be
1619documented here. Constraints on what can be done (e.g. duplication, moving, etc
1620need to be documented).
1621</p>
1622
1623</div>
1624
1625<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1626<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1627<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1628
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1629<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1630
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1631<p>The LLVM instruction set consists of several different
1632classifications of instructions: <a href="#terminators">terminator
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1633instructions</a>, <a href="#binaryops">binary instructions</a>,
1634<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1635 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1636instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1637
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1638</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1639
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1640<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1641<div class="doc_subsection"> <a name="terminators">Terminator
1642Instructions</a> </div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1643
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1644<div class="doc_text">
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1645
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1646<p>As mentioned <a href="#functionstructure">previously</a>, every
1647basic block in a program ends with a "Terminator" instruction, which
1648indicates which block should be executed after the current block is
1649finished. These terminator instructions typically yield a '<tt>void</tt>'
1650value: they produce control flow, not values (the one exception being
1651the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1652<p>There are six different terminator instructions: the '<a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1653 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1654instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1655the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1656 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1657 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1658
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1659</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1660
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1661<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1662<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1663Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1664<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1665<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1666<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]1667 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1668</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1669<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1670<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]1671value) from a function back to the caller.</p>
John Criswell4457dc92004-04-09 16:48:45 +0000[diff] [blame]1672<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1673returns a value and then causes control flow, and one that just causes
1674control flow to occur.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1675<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1676<p>The '<tt>ret</tt>' instruction may return any '<a
1677 href="#t_firstclass">first class</a>' type. Notice that a function is
1678not <a href="#wellformed">well formed</a> if there exists a '<tt>ret</tt>'
1679instruction inside of the function that returns a value that does not
1680match the return type of the function.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1681<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1682<p>When the '<tt>ret</tt>' instruction is executed, control flow
1683returns back to the calling function's context. If the caller is a "<a
John Criswellfa081872004-06-25 15:16:57 +0000[diff] [blame]1684 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1685the instruction after the call. If the caller was an "<a
1686 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1687at the beginning of the "normal" destination block. If the instruction
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1688returns a value, that value shall set the call or invoke instruction's
1689return value.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1690<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1691<pre> ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1692 ret void <i>; Return from a void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1693</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1694</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1695<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1696<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</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>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1699<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]1700</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1701<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1702<p>The '<tt>br</tt>' instruction is used to cause control flow to
1703transfer to a different basic block in the current function. There are
1704two forms of this instruction, corresponding to a conditional branch
1705and an unconditional branch.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1706<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1707<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1708single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1709unconditional form of the '<tt>br</tt>' instruction takes a single
1710'<tt>label</tt>' value as a target.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1711<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1712<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1713argument is evaluated. If the value is <tt>true</tt>, control flows
1714to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1715control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1716<h5>Example:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1717<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]1718 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]1719</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1720<!-- _______________________________________________________________________ -->
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1721<div class="doc_subsubsection">
1722 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1723</div>
1724
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1725<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1726<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1727
1728<pre>
1729 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1730</pre>
1731
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1732<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1733
1734<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1735several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1736instruction, allowing a branch to occur to one of many possible
1737destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1738
1739
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1740<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1741
1742<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1743comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1744an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1745table is not allowed to contain duplicate constant entries.</p>
1746
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1747<h5>Semantics:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1748
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1749<p>The <tt>switch</tt> instruction specifies a table of values and
1750destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1751table is searched for the given value. If the value is found, control flow is
1752transfered to the corresponding destination; otherwise, control flow is
1753transfered to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1754
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1755<h5>Implementation:</h5>
1756
1757<p>Depending on properties of the target machine and the particular
1758<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell84114752004-06-25 16:05:06 +0000[diff] [blame]1759ways. For example, it could be generated as a series of chained conditional
1760branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1761
1762<h5>Example:</h5>
1763
1764<pre>
1765 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]1766 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1767 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1768
1769 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1770 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]1771
1772 <i>; Implement a jump table:</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1773 switch i32 %val, label %otherwise [ i32 0, label %onzero
1774 i32 1, label %onone
1775 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1776</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1777</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1778
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1779<!-- _______________________________________________________________________ -->
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1780<div class="doc_subsubsection">
1781 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
1782</div>
1783
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1784<div class="doc_text">
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1785
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1786<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1787
1788<pre>
1789 &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]1790 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1791</pre>
1792
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]1793<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1794
1795<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
1796function, with the possibility of control flow transfer to either the
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1797'<tt>normal</tt>' label or the
1798'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1799"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
1800"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswelle4c57cc2005-05-12 16:52:32 +0000[diff] [blame]1801href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
1802continued at the dynamically nearest "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1803
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1804<h5>Arguments:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1805
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1806<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1807
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1808<ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1809 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]1810 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1811 convention</a> the call should use. If none is specified, the call defaults
1812 to using C calling conventions.
1813 </li>
1814 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
1815 function value being invoked. In most cases, this is a direct function
1816 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
1817 an arbitrary pointer to function value.
1818 </li>
1819
1820 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
1821 function to be invoked. </li>
1822
1823 <li>'<tt>function args</tt>': argument list whose types match the function
1824 signature argument types. If the function signature indicates the function
1825 accepts a variable number of arguments, the extra arguments can be
1826 specified. </li>
1827
1828 <li>'<tt>normal label</tt>': the label reached when the called function
1829 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
1830
1831 <li>'<tt>exception label</tt>': the label reached when a callee returns with
1832 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
1833
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1834</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1835
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1836<h5>Semantics:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1837
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1838<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1839href="#i_call">call</a></tt>' instruction in most regards. The primary
1840difference is that it establishes an association with a label, which is used by
1841the runtime library to unwind the stack.</p>
1842
1843<p>This instruction is used in languages with destructors to ensure that proper
1844cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
1845exception. Additionally, this is important for implementation of
1846'<tt>catch</tt>' clauses in high-level languages that support them.</p>
1847
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1848<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]1849<pre>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1850 %retval = invoke i32 %Test(i32 15) to label %Continue
1851 unwind label %TestCleanup <i>; {i32}:retval set</i>
1852 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Test(i32 15) to label %Continue
1853 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1854</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1855</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1856
1857
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1858<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1859
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1860<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
1861Instruction</a> </div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1862
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1863<div class="doc_text">
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1864
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1865<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1866<pre>
1867 unwind
1868</pre>
1869
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1870<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1871
1872<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
1873at the first callee in the dynamic call stack which used an <a
1874href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
1875primarily used to implement exception handling.</p>
1876
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]1877<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1878
1879<p>The '<tt>unwind</tt>' intrinsic causes execution of the current function to
1880immediately halt. The dynamic call stack is then searched for the first <a
1881href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
1882execution continues at the "exceptional" destination block specified by the
1883<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
1884dynamic call chain, undefined behavior results.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1885</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]1886
1887<!-- _______________________________________________________________________ -->
1888
1889<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
1890Instruction</a> </div>
1891
1892<div class="doc_text">
1893
1894<h5>Syntax:</h5>
1895<pre>
1896 unreachable
1897</pre>
1898
1899<h5>Overview:</h5>
1900
1901<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
1902instruction is used to inform the optimizer that a particular portion of the
1903code is not reachable. This can be used to indicate that the code after a
1904no-return function cannot be reached, and other facts.</p>
1905
1906<h5>Semantics:</h5>
1907
1908<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
1909</div>
1910
1911
1912
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1913<!-- ======================================================================= -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1914<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1915<div class="doc_text">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1916<p>Binary operators are used to do most of the computation in a
1917program. They require two operands, execute an operation on them, and
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]1918produce a single value. The operands might represent
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1919multiple 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]1920The result value of a binary operator is not
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1921necessarily the same type as its operands.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1922<p>There are several different binary operators:</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1923</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1924<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1925<div class="doc_subsubsection"> <a name="i_add">'<tt>add</tt>'
1926Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1927<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1928<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1929<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]1930</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1931<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1932<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1933<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1934<p>The two arguments to the '<tt>add</tt>' instruction must be either <a
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1935 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a> values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1936 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]1937Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1938<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1939<p>The value produced is the integer or floating point sum of the two
1940operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1941<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1942<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]1943</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1944</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1945<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1946<div class="doc_subsubsection"> <a name="i_sub">'<tt>sub</tt>'
1947Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1948<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1949<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1950<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]1951</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1952<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1953<p>The '<tt>sub</tt>' instruction returns the difference of its two
1954operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1955<p>Note that the '<tt>sub</tt>' instruction is used to represent the '<tt>neg</tt>'
1956instruction present in most other intermediate representations.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1957<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1958<p>The two arguments to the '<tt>sub</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1959 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1960values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1961This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1962Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1963<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1964<p>The value produced is the integer or floating point difference of
1965the two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1966<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]1967<pre>
1968 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1969 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1970</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1971</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1972<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1973<div class="doc_subsubsection"> <a name="i_mul">'<tt>mul</tt>'
1974Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1975<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1976<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1977<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]1978</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1979<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1980<p>The '<tt>mul</tt>' instruction returns the product of its two
1981operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1982<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1983<p>The two arguments to the '<tt>mul</tt>' instruction must be either <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1984 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1985values.
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]1986This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1987Both arguments must have identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1988<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1989<p>The value produced is the integer or floating point product of the
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1990two operands.</p>
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]1991<p>Because the operands are the same width, the result of an integer
1992multiplication is the same whether the operands should be deemed unsigned or
1993signed.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1994<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1995<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]1996</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1997</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1998<!-- _______________________________________________________________________ -->
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]1999<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2000</a></div>
2001<div class="doc_text">
2002<h5>Syntax:</h5>
2003<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2004</pre>
2005<h5>Overview:</h5>
2006<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2007operands.</p>
2008<h5>Arguments:</h5>
2009<p>The two arguments to the '<tt>udiv</tt>' instruction must be
2010<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2011types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2012of the values in which case the elements must be integers.</p>
2013<h5>Semantics:</h5>
2014<p>The value produced is the unsigned integer quotient of the two operands. This
2015instruction always performs an unsigned division operation, regardless of
2016whether the arguments are unsigned or not.</p>
2017<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2018<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]2019</pre>
2020</div>
2021<!-- _______________________________________________________________________ -->
2022<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2023</a> </div>
2024<div class="doc_text">
2025<h5>Syntax:</h5>
2026<pre> &lt;result&gt; = sdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2027</pre>
2028<h5>Overview:</h5>
2029<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2030operands.</p>
2031<h5>Arguments:</h5>
2032<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2033<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2034types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2035of the values in which case the elements must be integers.</p>
2036<h5>Semantics:</h5>
2037<p>The value produced is the signed integer quotient of the two operands. This
2038instruction always performs a signed division operation, regardless of whether
2039the arguments are signed or not.</p>
2040<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2041<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]2042</pre>
2043</div>
2044<!-- _______________________________________________________________________ -->
2045<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2046Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2047<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2048<h5>Syntax:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2049<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]2050</pre>
2051<h5>Overview:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2052<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2053operands.</p>
2054<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2055<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2056<a href="#t_floating">floating point</a> values. Both arguments must have
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2057identical types. This instruction can also take <a href="#t_vector">vector</a>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2058versions of floating point values.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2059<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2060<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2061<h5>Example:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]2062<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]2063</pre>
2064</div>
2065<!-- _______________________________________________________________________ -->
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2066<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2067</div>
2068<div class="doc_text">
2069<h5>Syntax:</h5>
2070<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2071</pre>
2072<h5>Overview:</h5>
2073<p>The '<tt>urem</tt>' instruction returns the remainder from the
2074unsigned division of its two arguments.</p>
2075<h5>Arguments:</h5>
2076<p>The two arguments to the '<tt>urem</tt>' instruction must be
2077<a href="#t_integer">integer</a> values. Both arguments must have identical
2078types.</p>
2079<h5>Semantics:</h5>
2080<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
2081This instruction always performs an unsigned division to get the remainder,
2082regardless of whether the arguments are unsigned or not.</p>
2083<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2084<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]2085</pre>
2086
2087</div>
2088<!-- _______________________________________________________________________ -->
2089<div class="doc_subsubsection"> <a name="i_srem">'<tt>srem</tt>'
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2090Instruction</a> </div>
2091<div class="doc_text">
2092<h5>Syntax:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2093<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]2094</pre>
2095<h5>Overview:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2096<p>The '<tt>srem</tt>' instruction returns the remainder from the
2097signed division of its two operands.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2098<h5>Arguments:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2099<p>The two arguments to the '<tt>srem</tt>' instruction must be
2100<a href="#t_integer">integer</a> values. Both arguments must have identical
2101types.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2102<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]2103<p>This instruction returns the <i>remainder</i> of a division (where the result
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2104has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
2105operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
2106a value. For more information about the difference, see <a
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2107 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2108Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer64f5c6c2007-03-24 22:40:44 +0000[diff] [blame]2109please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencerc9fdfc82007-03-24 22:23:39 +0000[diff] [blame]2110Wikipedia: modulo operation</a>.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2111<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2112<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]2113</pre>
2114
2115</div>
2116<!-- _______________________________________________________________________ -->
2117<div class="doc_subsubsection"> <a name="i_frem">'<tt>frem</tt>'
2118Instruction</a> </div>
2119<div class="doc_text">
2120<h5>Syntax:</h5>
2121<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2122</pre>
2123<h5>Overview:</h5>
2124<p>The '<tt>frem</tt>' instruction returns the remainder from the
2125division of its two operands.</p>
2126<h5>Arguments:</h5>
2127<p>The two arguments to the '<tt>frem</tt>' instruction must be
2128<a href="#t_floating">floating point</a> values. Both arguments must have
2129identical types.</p>
2130<h5>Semantics:</h5>
2131<p>This instruction returns the <i>remainder</i> of a division.</p>
2132<h5>Example:</h5>
2133<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]2134</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2135</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]2136
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2137<!-- ======================================================================= -->
2138<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2139Operations</a> </div>
2140<div class="doc_text">
2141<p>Bitwise binary operators are used to do various forms of
2142bit-twiddling in a program. They are generally very efficient
2143instructions and can commonly be strength reduced from other
2144instructions. They require two operands, execute an operation on them,
2145and produce a single value. The resulting value of the bitwise binary
2146operators is always the same type as its first operand.</p>
2147</div>
2148
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2149<!-- _______________________________________________________________________ -->
2150<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2151Instruction</a> </div>
2152<div class="doc_text">
2153<h5>Syntax:</h5>
2154<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2155</pre>
2156<h5>Overview:</h5>
2157<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2158the left a specified number of bits.</p>
2159<h5>Arguments:</h5>
2160<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
2161 href="#t_integer">integer</a> type.</p>
2162<h5>Semantics:</h5>
2163<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup>.</p>
2164<h5>Example:</h5><pre>
2165 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2166 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2167 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
2168</pre>
2169</div>
2170<!-- _______________________________________________________________________ -->
2171<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2172Instruction</a> </div>
2173<div class="doc_text">
2174<h5>Syntax:</h5>
2175<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2176</pre>
2177
2178<h5>Overview:</h5>
2179<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2180operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2181
2182<h5>Arguments:</h5>
2183<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
2184<a href="#t_integer">integer</a> type.</p>
2185
2186<h5>Semantics:</h5>
2187<p>This instruction always performs a logical shift right operation. The most
2188significant bits of the result will be filled with zero bits after the
2189shift.</p>
2190
2191<h5>Example:</h5>
2192<pre>
2193 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2194 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2195 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2196 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
2197</pre>
2198</div>
2199
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]2200<!-- _______________________________________________________________________ -->
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2201<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2202Instruction</a> </div>
2203<div class="doc_text">
2204
2205<h5>Syntax:</h5>
2206<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2207</pre>
2208
2209<h5>Overview:</h5>
2210<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2211operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]2212
2213<h5>Arguments:</h5>
2214<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
2215<a href="#t_integer">integer</a> type.</p>
2216
2217<h5>Semantics:</h5>
2218<p>This instruction always performs an arithmetic shift right operation,
2219The most significant bits of the result will be filled with the sign bit
2220of <tt>var1</tt>.</p>
2221
2222<h5>Example:</h5>
2223<pre>
2224 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2225 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2226 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2227 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
2228</pre>
2229</div>
2230
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2231<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2232<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2233Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2234<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2235<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2236<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]2237</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2238<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2239<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2240its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2241<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2242<p>The two arguments to the '<tt>and</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2243 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2244identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2245<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2246<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2247<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2248<div style="align: center">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2249<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2250 <tbody>
2251 <tr>
2252 <td>In0</td>
2253 <td>In1</td>
2254 <td>Out</td>
2255 </tr>
2256 <tr>
2257 <td>0</td>
2258 <td>0</td>
2259 <td>0</td>
2260 </tr>
2261 <tr>
2262 <td>0</td>
2263 <td>1</td>
2264 <td>0</td>
2265 </tr>
2266 <tr>
2267 <td>1</td>
2268 <td>0</td>
2269 <td>0</td>
2270 </tr>
2271 <tr>
2272 <td>1</td>
2273 <td>1</td>
2274 <td>1</td>
2275 </tr>
2276 </tbody>
2277</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2278</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2279<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2280<pre> &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
2281 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2282 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2283</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2284</div>
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_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2287<div class="doc_text">
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2288<h5>Syntax:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2289<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]2290</pre>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2291<h5>Overview:</h5>
2292<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2293or of its two operands.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2294<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2295<p>The two arguments to the '<tt>or</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2296 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2297identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2298<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2299<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2300<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2301<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2302<table border="1" cellspacing="0" cellpadding="4">
2303 <tbody>
2304 <tr>
2305 <td>In0</td>
2306 <td>In1</td>
2307 <td>Out</td>
2308 </tr>
2309 <tr>
2310 <td>0</td>
2311 <td>0</td>
2312 <td>0</td>
2313 </tr>
2314 <tr>
2315 <td>0</td>
2316 <td>1</td>
2317 <td>1</td>
2318 </tr>
2319 <tr>
2320 <td>1</td>
2321 <td>0</td>
2322 <td>1</td>
2323 </tr>
2324 <tr>
2325 <td>1</td>
2326 <td>1</td>
2327 <td>1</td>
2328 </tr>
2329 </tbody>
2330</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2331</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2332<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2333<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2334 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2335 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2336</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2337</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2338<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2339<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2340Instruction</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; = 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]2344</pre>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2345<h5>Overview:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2346<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2347or of its two operands. The <tt>xor</tt> is used to implement the
2348"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2349<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2350<p>The two arguments to the '<tt>xor</tt>' instruction must be <a
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2351 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2352identical types.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2353<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2354<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2355<p> </p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2356<div style="align: center">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2357<table border="1" cellspacing="0" cellpadding="4">
2358 <tbody>
2359 <tr>
2360 <td>In0</td>
2361 <td>In1</td>
2362 <td>Out</td>
2363 </tr>
2364 <tr>
2365 <td>0</td>
2366 <td>0</td>
2367 <td>0</td>
2368 </tr>
2369 <tr>
2370 <td>0</td>
2371 <td>1</td>
2372 <td>1</td>
2373 </tr>
2374 <tr>
2375 <td>1</td>
2376 <td>0</td>
2377 <td>1</td>
2378 </tr>
2379 <tr>
2380 <td>1</td>
2381 <td>1</td>
2382 <td>0</td>
2383 </tr>
2384 </tbody>
2385</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2386</div>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2387<p> </p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2388<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2389<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2390 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2391 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2392 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2393</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2394</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2395
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2396<!-- ======================================================================= -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2397<div class="doc_subsection">
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2398 <a name="vectorops">Vector Operations</a>
2399</div>
2400
2401<div class="doc_text">
2402
2403<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2404target-independent manner. These instructions cover the element-access and
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2405vector-specific operations needed to process vectors effectively. While LLVM
2406does directly support these vector operations, many sophisticated algorithms
2407will want to use target-specific intrinsics to take full advantage of a specific
2408target.</p>
2409
2410</div>
2411
2412<!-- _______________________________________________________________________ -->
2413<div class="doc_subsubsection">
2414 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2415</div>
2416
2417<div class="doc_text">
2418
2419<h5>Syntax:</h5>
2420
2421<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2422 &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]2423</pre>
2424
2425<h5>Overview:</h5>
2426
2427<p>
2428The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2429element from a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2430</p>
2431
2432
2433<h5>Arguments:</h5>
2434
2435<p>
2436The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2437value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2438an index indicating the position from which to extract the element.
2439The index may be a variable.</p>
2440
2441<h5>Semantics:</h5>
2442
2443<p>
2444The result is a scalar of the same type as the element type of
2445<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2446<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2447results are undefined.
2448</p>
2449
2450<h5>Example:</h5>
2451
2452<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2453 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2454</pre>
2455</div>
2456
2457
2458<!-- _______________________________________________________________________ -->
2459<div class="doc_subsubsection">
2460 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2461</div>
2462
2463<div class="doc_text">
2464
2465<h5>Syntax:</h5>
2466
2467<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2468 &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]2469</pre>
2470
2471<h5>Overview:</h5>
2472
2473<p>
2474The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2475element into a vector at a specified index.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2476</p>
2477
2478
2479<h5>Arguments:</h5>
2480
2481<p>
2482The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2483value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2484scalar value whose type must equal the element type of the first
2485operand. The third operand is an index indicating the position at
2486which to insert the value. The index may be a variable.</p>
2487
2488<h5>Semantics:</h5>
2489
2490<p>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2491The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2492element values are those of <tt>val</tt> except at position
2493<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2494exceeds the length of <tt>val</tt>, the results are undefined.
2495</p>
2496
2497<h5>Example:</h5>
2498
2499<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2500 %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]2501</pre>
2502</div>
2503
2504<!-- _______________________________________________________________________ -->
2505<div class="doc_subsubsection">
2506 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2507</div>
2508
2509<div class="doc_text">
2510
2511<h5>Syntax:</h5>
2512
2513<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2514 &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]2515</pre>
2516
2517<h5>Overview:</h5>
2518
2519<p>
2520The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2521from two input vectors, returning a vector of the same type.
2522</p>
2523
2524<h5>Arguments:</h5>
2525
2526<p>
2527The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2528with types that match each other and types that match the result of the
2529instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2530of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2531</p>
2532
2533<p>
2534The shuffle mask operand is required to be a constant vector with either
2535constant integer or undef values.
2536</p>
2537
2538<h5>Semantics:</h5>
2539
2540<p>
2541The elements of the two input vectors are numbered from left to right across
2542both of the vectors. The shuffle mask operand specifies, for each element of
2543the result vector, which element of the two input registers the result element
2544gets. The element selector may be undef (meaning "don't care") and the second
2545operand may be undef if performing a shuffle from only one vector.
2546</p>
2547
2548<h5>Example:</h5>
2549
2550<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2551 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2552 &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]2553 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2554 &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]2555</pre>
2556</div>
2557
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]2558
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]2559<!-- ======================================================================= -->
2560<div class="doc_subsection">
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2561 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2562</div>
2563
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2564<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2565
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2566<p>A key design point of an SSA-based representation is how it
2567represents memory. In LLVM, no memory locations are in SSA form, which
2568makes things very simple. This section describes how to read, write,
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2569allocate, and free memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2570
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2571</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2572
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2573<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2574<div class="doc_subsubsection">
2575 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
2576</div>
2577
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2578<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2579
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2580<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2581
2582<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2583 &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]2584</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2585
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2586<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2587
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2588<p>The '<tt>malloc</tt>' instruction allocates memory from the system
2589heap and returns a pointer to it.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2590
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2591<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2592
2593<p>The '<tt>malloc</tt>' instruction allocates
2594<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswell6e4ca612004-02-24 16:13:56 +0000[diff] [blame]2595bytes of memory from the operating system and returns a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2596appropriate type to the program. If "NumElements" is specified, it is the
2597number of elements allocated. If an alignment is specified, the value result
2598of the allocation is guaranteed to be aligned to at least that boundary. If
2599not specified, or if zero, the target can choose to align the allocation on any
2600convenient boundary.</p>
2601
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2602<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2603
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2604<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2605
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2606<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
2607a pointer is returned.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2608
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2609<h5>Example:</h5>
2610
2611<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2612 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2613
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]2614 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
2615 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
2616 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
2617 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
2618 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2619</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2620</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2621
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2622<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2623<div class="doc_subsubsection">
2624 <a name="i_free">'<tt>free</tt>' Instruction</a>
2625</div>
2626
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2627<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2628
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2629<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2630
2631<pre>
2632 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2633</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2634
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2635<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2636
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2637<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2638memory heap to be reallocated in the future.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2639
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2640<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2641
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2642<p>'<tt>value</tt>' shall be a pointer value that points to a value
2643that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
2644instruction.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2645
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2646<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2647
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2648<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2649after this instruction executes.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2650
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2651<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2652
2653<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2654 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
2655 free [4 x i8]* %array
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2656</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2657</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2658
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2659<!-- _______________________________________________________________________ -->
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2660<div class="doc_subsubsection">
2661 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
2662</div>
2663
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2664<div class="doc_text">
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2665
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2666<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2667
2668<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2669 &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]2670</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2671
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2672<h5>Overview:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2673
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2674<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
2675currently executing function, to be automatically released when this function
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2676returns to its caller.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2677
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2678<h5>Arguments:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2679
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2680<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2681bytes of memory on the runtime stack, returning a pointer of the
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2682appropriate type to the program. If "NumElements" is specified, it is the
2683number of elements allocated. If an alignment is specified, the value result
2684of the allocation is guaranteed to be aligned to at least that boundary. If
2685not specified, or if zero, the target can choose to align the allocation on any
2686convenient boundary.</p>
2687
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2688<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2689
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2690<h5>Semantics:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2691
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2692<p>Memory is allocated; a pointer is returned. '<tt>alloca</tt>'d
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2693memory is automatically released when the function returns. The '<tt>alloca</tt>'
2694instruction is commonly used to represent automatic variables that must
2695have an address available. When the function returns (either with the <tt><a
John Criswelldae2e932005-05-12 16:55:34 +0000[diff] [blame]2696 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]2697instructions), the memory is reclaimed.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2698
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2699<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2700
2701<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2702 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2703 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
2704 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2705 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2706</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2707</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]2708
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2709<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2710<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
2711Instruction</a> </div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2712<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2713<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2714<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]2715<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2716<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2717<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2718<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2719address from which to load. The pointer must point to a <a
Chris Lattnere53e5082004-06-03 22:57:15 +0000[diff] [blame]2720 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]2721marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2722the number or order of execution of this <tt>load</tt> with other
2723volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
2724instructions. </p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2725<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2726<p>The location of memory pointed to is loaded.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2727<h5>Examples:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2728<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2729 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2730 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
2731 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2732</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2733</div>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2734<!-- _______________________________________________________________________ -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2735<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
2736Instruction</a> </div>
Reid Spencer035ab572006-11-09 21:18:01 +0000[diff] [blame]2737<div class="doc_text">
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2738<h5>Syntax:</h5>
Christopher Lamb2330e4d2007-04-21 08:16:25 +0000[diff] [blame]2739<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
2740 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]2741</pre>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2742<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2743<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2744<h5>Arguments:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2745<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2746to 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]2747operand must be a pointer to the type of the '<tt>&lt;value&gt;</tt>'
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2748operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2749optimizer is not allowed to modify the number or order of execution of
2750this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
2751 href="#i_store">store</a></tt> instructions.</p>
2752<h5>Semantics:</h5>
2753<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
2754at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2755<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2756<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2757 <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2758 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
2759 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2760</pre>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2761</div>
2762
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]2763<!-- _______________________________________________________________________ -->
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2764<div class="doc_subsubsection">
2765 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
2766</div>
2767
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2768<div class="doc_text">
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2769<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2770<pre>
2771 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
2772</pre>
2773
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2774<h5>Overview:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2775
2776<p>
2777The '<tt>getelementptr</tt>' instruction is used to get the address of a
2778subelement of an aggregate data structure.</p>
2779
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2780<h5>Arguments:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2781
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2782<p>This instruction takes a list of integer operands that indicate what
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2783elements of the aggregate object to index to. The actual types of the arguments
2784provided depend on the type of the first pointer argument. The
2785'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]2786levels 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]2787structure, only <tt>i32</tt> integer constants are allowed. When indexing
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2788into an array or pointer, only integers of 32 or 64 bits are allowed, and will
2789be sign extended to 64-bit values.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2790
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2791<p>For example, let's consider a C code fragment and how it gets
2792compiled to LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2793
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2794<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2795<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2796struct RT {
2797 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2798 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2799 char C;
2800};
2801struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2802 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2803 double Y;
2804 struct RT Z;
2805};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2806
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]2807int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2808 return &amp;s[1].Z.B[5][13];
2809}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2810</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2811</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2812
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2813<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2814
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2815<div class="doc_code">
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2816<pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2817%RT = type { i8 , [10 x [20 x i32]], i8 }
2818%ST = type { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2819
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2820define i32* %foo(%ST* %s) {
2821entry:
2822 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
2823 ret i32* %reg
2824}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2825</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2826</div>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2827
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2828<h5>Semantics:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2829
2830<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswellc1f786c2005-05-13 22:25:59 +0000[diff] [blame]2831on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer85f5b5b2006-12-04 21:29:24 +0000[diff] [blame]2832and <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]2833<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]2834to 64-bits. <a href="#t_struct">Structure</a> types require <tt>i32</tt>
Reid Spencer42ddd842006-12-03 16:53:48 +0000[diff] [blame]2835<b>constants</b>.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2836
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2837<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]2838type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2839}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2840the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
2841i8 }</tt>' type, another structure. The third index indexes into the second
2842element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2843array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2844'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
2845to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2846
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2847<p>Note that it is perfectly legal to index partially through a
2848structure, returning a pointer to an inner element. Because of this,
2849the LLVM code for the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2850
2851<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2852 define i32* %foo(%ST* %s) {
2853 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2854 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
2855 %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]2856 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
2857 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
2858 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2859 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2860</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2861
2862<p>Note that it is undefined to access an array out of bounds: array and
2863pointer indexes must always be within the defined bounds of the array type.
2864The one exception for this rules is zero length arrays. These arrays are
2865defined to be accessible as variable length arrays, which requires access
2866beyond the zero'th element.</p>
2867
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]2868<p>The getelementptr instruction is often confusing. For some more insight
2869into how it works, see <a href="GetElementPtr.html">the getelementptr
2870FAQ</a>.</p>
2871
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2872<h5>Example:</h5>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]2873
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2874<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2875 <i>; yields [12 x i8]*:aptr</i>
2876 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2877</pre>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]2878</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]2879
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2880<!-- ======================================================================= -->
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]2881<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2882</div>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2883<div class="doc_text">
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]2884<p>The instructions in this category are the conversion instructions (casting)
2885which all take a single operand and a type. They perform various bit conversions
2886on the operand.</p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2887</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]2888
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]2889<!-- _______________________________________________________________________ -->
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]2890<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2891 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
2892</div>
2893<div class="doc_text">
2894
2895<h5>Syntax:</h5>
2896<pre>
2897 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2898</pre>
2899
2900<h5>Overview:</h5>
2901<p>
2902The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
2903</p>
2904
2905<h5>Arguments:</h5>
2906<p>
2907The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
2908be 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]2909and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2910type. The bit size of <tt>value</tt> must be larger than the bit size of
2911<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2912
2913<h5>Semantics:</h5>
2914<p>
2915The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2916and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
2917larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
2918It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2919
2920<h5>Example:</h5>
2921<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2922 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2923 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
2924 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2925</pre>
2926</div>
2927
2928<!-- _______________________________________________________________________ -->
2929<div class="doc_subsubsection">
2930 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
2931</div>
2932<div class="doc_text">
2933
2934<h5>Syntax:</h5>
2935<pre>
2936 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2937</pre>
2938
2939<h5>Overview:</h5>
2940<p>The '<tt>zext</tt>' instruction zero extends its operand to type
2941<tt>ty2</tt>.</p>
2942
2943
2944<h5>Arguments:</h5>
2945<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]2946<a href="#t_integer">integer</a> type, and a type to cast it to, which must
2947also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2948<tt>value</tt> must be smaller than the bit size of the destination type,
2949<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2950
2951<h5>Semantics:</h5>
2952<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]2953bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2954
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]2955<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]2956
2957<h5>Example:</h5>
2958<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2959 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2960 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2961</pre>
2962</div>
2963
2964<!-- _______________________________________________________________________ -->
2965<div class="doc_subsubsection">
2966 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
2967</div>
2968<div class="doc_text">
2969
2970<h5>Syntax:</h5>
2971<pre>
2972 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2973</pre>
2974
2975<h5>Overview:</h5>
2976<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
2977
2978<h5>Arguments:</h5>
2979<p>
2980The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]2981<a href="#t_integer">integer</a> type, and a type to cast it to, which must
2982also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]2983<tt>value</tt> must be smaller than the bit size of the destination type,
2984<tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2985
2986<h5>Semantics:</h5>
2987<p>
2988The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
2989bit (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]2990the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2991
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2992<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]2993
2994<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2995<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2996 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2997 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2998</pre>
2999</div>
3000
3001<!-- _______________________________________________________________________ -->
3002<div class="doc_subsubsection">
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3003 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3004</div>
3005
3006<div class="doc_text">
3007
3008<h5>Syntax:</h5>
3009
3010<pre>
3011 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3012</pre>
3013
3014<h5>Overview:</h5>
3015<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3016<tt>ty2</tt>.</p>
3017
3018
3019<h5>Arguments:</h5>
3020<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3021 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3022cast it to. The size of <tt>value</tt> must be larger than the size of
3023<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3024<i>no-op cast</i>.</p>
3025
3026<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3027<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3028<a href="#t_floating">floating point</a> type to a smaller
3029<a href="#t_floating">floating point</a> type. If the value cannot fit within
3030the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]3031
3032<h5>Example:</h5>
3033<pre>
3034 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3035 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3036</pre>
3037</div>
3038
3039<!-- _______________________________________________________________________ -->
3040<div class="doc_subsubsection">
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3041 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3042</div>
3043<div class="doc_text">
3044
3045<h5>Syntax:</h5>
3046<pre>
3047 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3048</pre>
3049
3050<h5>Overview:</h5>
3051<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3052floating point value.</p>
3053
3054<h5>Arguments:</h5>
3055<p>The '<tt>fpext</tt>' instruction takes a
3056<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3057and a <a href="#t_floating">floating point</a> type to cast it to. The source
3058type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3059
3060<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3061<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3062<a href="#t_floating">floating point</a> type to a larger
3063<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3064used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3065<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]3066
3067<h5>Example:</h5>
3068<pre>
3069 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3070 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3071</pre>
3072</div>
3073
3074<!-- _______________________________________________________________________ -->
3075<div class="doc_subsubsection">
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]3076 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3077</div>
3078<div class="doc_text">
3079
3080<h5>Syntax:</h5>
3081<pre>
3082 &lt;result&gt; = fp2uint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3083</pre>
3084
3085<h5>Overview:</h5>
3086<p>The '<tt>fp2uint</tt>' converts a floating point <tt>value</tt> to its
3087unsigned integer equivalent of type <tt>ty2</tt>.
3088</p>
3089
3090<h5>Arguments:</h5>
3091<p>The '<tt>fp2uint</tt>' instruction takes a value to cast, which must be a
3092<a href="#t_floating">floating point</a> value, and a type to cast it to, which
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3093must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3094
3095<h5>Semantics:</h5>
3096<p> The '<tt>fp2uint</tt>' instruction converts its
3097<a href="#t_floating">floating point</a> operand into the nearest (rounding
3098towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3099the results are undefined.</p>
3100
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3101<p>When converting to i1, the conversion is done as a comparison against
3102zero. If the <tt>value</tt> was zero, the i1 result will be <tt>false</tt>.
3103If the <tt>value</tt> was non-zero, the i1 result will be <tt>true</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3104
3105<h5>Example:</h5>
3106<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3107 %X = fp2uint double 123.0 to i32 <i>; yields i32:123</i>
3108 %Y = fp2uint float 1.0E+300 to i1 <i>; yields i1:true</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3109 %X = fp2uint float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3110</pre>
3111</div>
3112
3113<!-- _______________________________________________________________________ -->
3114<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3115 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3116</div>
3117<div class="doc_text">
3118
3119<h5>Syntax:</h5>
3120<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3121 &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]3122</pre>
3123
3124<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3125<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3126<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]3127</p>
3128
3129
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3130<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3131<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3132<a href="#t_floating">floating point</a> value, and a type to cast it to, which
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3133must also be an <a href="#t_integer">integer</a> type.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3134
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3135<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3136<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3137<a href="#t_floating">floating point</a> operand into the nearest (rounding
3138towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3139the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3140
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3141<p>When converting to i1, the conversion is done as a comparison against
3142zero. If the <tt>value</tt> was zero, the i1 result will be <tt>false</tt>.
3143If the <tt>value</tt> was non-zero, the i1 result will be <tt>true</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3144
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3145<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3146<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3147 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
3148 %Y = fptosi float 1.0E-247 to i1 <i>; yields i1:true</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3149 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3150</pre>
3151</div>
3152
3153<!-- _______________________________________________________________________ -->
3154<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3155 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3156</div>
3157<div class="doc_text">
3158
3159<h5>Syntax:</h5>
3160<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3161 &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]3162</pre>
3163
3164<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3165<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3166integer and converts that value to the <tt>ty2</tt> type.</p>
3167
3168
3169<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3170<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be an
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3171<a href="#t_integer">integer</a> value, and a type to cast it to, which must
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3172be a <a href="#t_floating">floating point</a> type.</p>
3173
3174<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3175<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3176integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3177the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3178
3179
3180<h5>Example:</h5>
3181<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3182 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3183 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3184</pre>
3185</div>
3186
3187<!-- _______________________________________________________________________ -->
3188<div class="doc_subsubsection">
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3189 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3190</div>
3191<div class="doc_text">
3192
3193<h5>Syntax:</h5>
3194<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3195 &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]3196</pre>
3197
3198<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3199<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3200integer and converts that value to the <tt>ty2</tt> type.</p>
3201
3202<h5>Arguments:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3203<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be an
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3204<a href="#t_integer">integer</a> value, and a type to cast it to, which must be
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3205a <a href="#t_floating">floating point</a> type.</p>
3206
3207<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]3208<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3209integer quantity and converts it to the corresponding floating point value. If
Jeff Cohencb757312007-04-22 14:56:37 +0000[diff] [blame]3210the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3211
3212<h5>Example:</h5>
3213<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3214 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3215 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3216</pre>
3217</div>
3218
3219<!-- _______________________________________________________________________ -->
3220<div class="doc_subsubsection">
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3221 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3222</div>
3223<div class="doc_text">
3224
3225<h5>Syntax:</h5>
3226<pre>
3227 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3228</pre>
3229
3230<h5>Overview:</h5>
3231<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3232the integer type <tt>ty2</tt>.</p>
3233
3234<h5>Arguments:</h5>
3235<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3236must 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]3237<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3238
3239<h5>Semantics:</h5>
3240<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3241<tt>ty2</tt> by interpreting the pointer value as an integer and either
3242truncating or zero extending that value to the size of the integer type. If
3243<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3244<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]3245are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3246change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3247
3248<h5>Example:</h5>
3249<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3250 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3251 %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]3252</pre>
3253</div>
3254
3255<!-- _______________________________________________________________________ -->
3256<div class="doc_subsubsection">
3257 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3258</div>
3259<div class="doc_text">
3260
3261<h5>Syntax:</h5>
3262<pre>
3263 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3264</pre>
3265
3266<h5>Overview:</h5>
3267<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3268a pointer type, <tt>ty2</tt>.</p>
3269
3270<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3271<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3272value to cast, and a type to cast it to, which must be a
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]3273<a href="#t_pointer">pointer</a> type.
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3274
3275<h5>Semantics:</h5>
3276<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3277<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3278the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3279size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3280the size of a pointer then a zero extension is done. If they are the same size,
3281nothing is done (<i>no-op cast</i>).</p>
3282
3283<h5>Example:</h5>
3284<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3285 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3286 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3287 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3288</pre>
3289</div>
3290
3291<!-- _______________________________________________________________________ -->
3292<div class="doc_subsubsection">
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3293 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3294</div>
3295<div class="doc_text">
3296
3297<h5>Syntax:</h5>
3298<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3299 &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]3300</pre>
3301
3302<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3303<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3304<tt>ty2</tt> without changing any bits.</p>
3305
3306<h5>Arguments:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3307<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3308a first class value, and a type to cast it to, which must also be a <a
3309 href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencer19b569f2007-01-09 20:08:58 +0000[diff] [blame]3310and the destination type, <tt>ty2</tt>, must be identical. If the source
3311type is a pointer, the destination type must also be a pointer.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3312
3313<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]3314<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]3315<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3316this conversion. The conversion is done as if the <tt>value</tt> had been
3317stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3318converted to other pointer types with this instruction. To convert pointers to
3319other types, use the <a href="#i_inttoptr">inttoptr</a> or
3320<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]3321
3322<h5>Example:</h5>
3323<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3324 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3325 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3326 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]3327</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3328</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3329
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3330<!-- ======================================================================= -->
3331<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3332<div class="doc_text">
3333<p>The instructions in this category are the "miscellaneous"
3334instructions, which defy better classification.</p>
3335</div>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3336
3337<!-- _______________________________________________________________________ -->
3338<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3339</div>
3340<div class="doc_text">
3341<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3342<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]3343</pre>
3344<h5>Overview:</h5>
3345<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
3346of its two integer operands.</p>
3347<h5>Arguments:</h5>
3348<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3349the condition code indicating the kind of comparison to perform. It is not
3350a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3351<ol>
3352 <li><tt>eq</tt>: equal</li>
3353 <li><tt>ne</tt>: not equal </li>
3354 <li><tt>ugt</tt>: unsigned greater than</li>
3355 <li><tt>uge</tt>: unsigned greater or equal</li>
3356 <li><tt>ult</tt>: unsigned less than</li>
3357 <li><tt>ule</tt>: unsigned less or equal</li>
3358 <li><tt>sgt</tt>: signed greater than</li>
3359 <li><tt>sge</tt>: signed greater or equal</li>
3360 <li><tt>slt</tt>: signed less than</li>
3361 <li><tt>sle</tt>: signed less or equal</li>
3362</ol>
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]3363<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3364<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3365<h5>Semantics:</h5>
3366<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3367the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3368yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3369<ol>
3370 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3371 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3372 </li>
3373 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3374 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3375 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
3376 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3377 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
3378 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3379 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
3380 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3381 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
3382 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
3383 <li><tt>sgt</tt>: interprets the operands as signed values and yields
3384 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3385 <li><tt>sge</tt>: interprets the operands as signed values and yields
3386 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3387 <li><tt>slt</tt>: interprets the operands as signed values and yields
3388 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3389 <li><tt>sle</tt>: interprets the operands as signed values and yields
3390 <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]3391</ol>
3392<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3393values are compared as if they were integers.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3394
3395<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3396<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3397 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3398 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3399 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3400 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3401 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3402</pre>
3403</div>
3404
3405<!-- _______________________________________________________________________ -->
3406<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3407</div>
3408<div class="doc_text">
3409<h5>Syntax:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3410<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]3411</pre>
3412<h5>Overview:</h5>
3413<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
3414of its floating point operands.</p>
3415<h5>Arguments:</h5>
3416<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3417the condition code indicating the kind of comparison to perform. It is not
3418a value, just a keyword. The possible condition code are:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3419<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3420 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3421 <li><tt>oeq</tt>: ordered and equal</li>
3422 <li><tt>ogt</tt>: ordered and greater than </li>
3423 <li><tt>oge</tt>: ordered and greater than or equal</li>
3424 <li><tt>olt</tt>: ordered and less than </li>
3425 <li><tt>ole</tt>: ordered and less than or equal</li>
3426 <li><tt>one</tt>: ordered and not equal</li>
3427 <li><tt>ord</tt>: ordered (no nans)</li>
3428 <li><tt>ueq</tt>: unordered or equal</li>
3429 <li><tt>ugt</tt>: unordered or greater than </li>
3430 <li><tt>uge</tt>: unordered or greater than or equal</li>
3431 <li><tt>ult</tt>: unordered or less than </li>
3432 <li><tt>ule</tt>: unordered or less than or equal</li>
3433 <li><tt>une</tt>: unordered or not equal</li>
3434 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3435 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3436</ol>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3437<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer93a49852006-12-06 07:08:07 +0000[diff] [blame]3438<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer350f8aa2007-01-04 05:19:58 +0000[diff] [blame]3439<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
3440<a href="#t_floating">floating point</a> typed. They must have identical
3441types.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3442<h5>Semantics:</h5>
3443<p>The '<tt>fcmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3444the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3445yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3446<ol>
3447 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3448 <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]3449 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3450 <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]3451 <tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3452 <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]3453 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3454 <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]3455 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3456 <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]3457 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3458 <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]3459 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3460 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3461 <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]3462 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3463 <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]3464 <tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3465 <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]3466 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3467 <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]3468 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3469 <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]3470 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3471 <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]3472 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]3473 <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]3474 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
3475</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]3476
3477<h5>Example:</h5>
3478<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
3479 &lt;result&gt; = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
3480 &lt;result&gt; = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
3481 &lt;result&gt; = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
3482</pre>
3483</div>
3484
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3485<!-- _______________________________________________________________________ -->
3486<div class="doc_subsubsection"> <a name="i_phi">'<tt>phi</tt>'
3487Instruction</a> </div>
3488<div class="doc_text">
3489<h5>Syntax:</h5>
3490<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
3491<h5>Overview:</h5>
3492<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
3493the SSA graph representing the function.</p>
3494<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3495<p>The type of the incoming values is specified with the first type
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3496field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
3497as arguments, with one pair for each predecessor basic block of the
3498current block. Only values of <a href="#t_firstclass">first class</a>
3499type may be used as the value arguments to the PHI node. Only labels
3500may be used as the label arguments.</p>
3501<p>There must be no non-phi instructions between the start of a basic
3502block and the PHI instructions: i.e. PHI instructions must be first in
3503a basic block.</p>
3504<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3505<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
3506specified by the pair corresponding to the predecessor basic block that executed
3507just prior to the current block.</p>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]3508<h5>Example:</h5>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3509<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]3510</div>
3511
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3512<!-- _______________________________________________________________________ -->
3513<div class="doc_subsubsection">
3514 <a name="i_select">'<tt>select</tt>' Instruction</a>
3515</div>
3516
3517<div class="doc_text">
3518
3519<h5>Syntax:</h5>
3520
3521<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3522 &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]3523</pre>
3524
3525<h5>Overview:</h5>
3526
3527<p>
3528The '<tt>select</tt>' instruction is used to choose one value based on a
3529condition, without branching.
3530</p>
3531
3532
3533<h5>Arguments:</h5>
3534
3535<p>
3536The '<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.
3537</p>
3538
3539<h5>Semantics:</h5>
3540
3541<p>
3542If the boolean condition evaluates to true, the instruction returns the first
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3543value argument; otherwise, it returns the second value argument.
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3544</p>
3545
3546<h5>Example:</h5>
3547
3548<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3549 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]3550</pre>
3551</div>
3552
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]3553
3554<!-- _______________________________________________________________________ -->
3555<div class="doc_subsubsection">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3556 <a name="i_call">'<tt>call</tt>' Instruction</a>
3557</div>
3558
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3559<div class="doc_text">
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3560
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3561<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3562<pre>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3563 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] &lt;ty&gt;* &lt;fnptrval&gt;(&lt;param list&gt;)
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3564</pre>
3565
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3566<h5>Overview:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3567
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3568<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3569
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3570<h5>Arguments:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3571
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3572<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3573
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3574<ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3575 <li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3576 <p>The optional "tail" marker indicates whether the callee function accesses
3577 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3578 function call is eligible for tail call optimization. Note that calls may
3579 be marked "tail" even if they do not occur before a <a
3580 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3581 </li>
3582 <li>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]3583 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3584 convention</a> the call should use. If none is specified, the call defaults
3585 to using C calling conventions.
3586 </li>
3587 <li>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3588 <p>'<tt>ty</tt>': shall be the signature of the pointer to function value
3589 being invoked. The argument types must match the types implied by this
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3590 signature. This type can be omitted if the function is not varargs and
3591 if the function type does not return a pointer to a function.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3592 </li>
3593 <li>
3594 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
3595 be invoked. In most cases, this is a direct function invocation, but
3596 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3597 to function value.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3598 </li>
3599 <li>
3600 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencera7e302a2005-05-01 22:22:57 +0000[diff] [blame]3601 function signature argument types. All arguments must be of
3602 <a href="#t_firstclass">first class</a> type. If the function signature
3603 indicates the function accepts a variable number of arguments, the extra
3604 arguments can be specified.</p>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3605 </li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3606</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3607
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3608<h5>Semantics:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3609
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3610<p>The '<tt>call</tt>' instruction is used to cause control flow to
3611transfer to a specified function, with its incoming arguments bound to
3612the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
3613instruction in the called function, control flow continues with the
3614instruction after the function call, and the return value of the
3615function is bound to the result argument. This is a simpler case of
3616the <a href="#i_invoke">invoke</a> instruction.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3617
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3618<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3619
3620<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3621 %retval = call i32 %test(i32 %argc)
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3622 call i32(i8 *, ...) *%printf(i8 * %msg, i32 12, i8 42);
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3623 %X = tail call i32 %foo()
3624 %Y = tail call <a href="#callingconv">fastcc</a> i32 %foo()
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]3625</pre>
3626
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3627</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3628
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3629<!-- _______________________________________________________________________ -->
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3630<div class="doc_subsubsection">
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3631 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3632</div>
3633
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3634<div class="doc_text">
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3635
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3636<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3637
3638<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3639 &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]3640</pre>
3641
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3642<h5>Overview:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3643
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3644<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3645the "variable argument" area of a function call. It is used to implement the
3646<tt>va_arg</tt> macro in C.</p>
3647
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3648<h5>Arguments:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3649
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3650<p>This instruction takes a <tt>va_list*</tt> value and the type of
3651the argument. It returns a value of the specified argument type and
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3652increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3653actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3654
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3655<h5>Semantics:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3656
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3657<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
3658type from the specified <tt>va_list</tt> and causes the
3659<tt>va_list</tt> to point to the next argument. For more information,
3660see the variable argument handling <a href="#int_varargs">Intrinsic
3661Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3662
3663<p>It is legal for this instruction to be called in a function which does not
3664take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3665function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3666
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3667<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3668href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3669argument.</p>
3670
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]3671<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]3672
3673<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
3674
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3675</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3676
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3677<!-- *********************************************************************** -->
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3678<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
3679<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3680
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3681<div class="doc_text">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3682
3683<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3684well known names and semantics and are required to follow certain restrictions.
3685Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3686language that does not require changing all of the transformations in LLVM when
3687adding to the language (or the bytecode reader/writer, the parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3688
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]3689<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3690prefix is reserved in LLVM for intrinsic names; thus, function names may not
3691begin with this prefix. Intrinsic functions must always be external functions:
3692you cannot define the body of intrinsic functions. Intrinsic functions may
3693only be used in call or invoke instructions: it is illegal to take the address
3694of an intrinsic function. Additionally, because intrinsic functions are part
3695of the LLVM language, it is required if any are added that they be documented
3696here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3697
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3698<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3699a family of functions that perform the same operation but on different data
3700types. This is most frequent with the integer types. Since LLVM can represent
3701over 8 million different integer types, there is a way to declare an intrinsic
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3702that can be overloaded based on its arguments. Such an intrinsic will have the
3703names of its argument types encoded into its function name, each
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3704preceded by a period. For example, the <tt>llvm.ctpop</tt> function can take an
3705integer of any width. This leads to a family of functions such as
3706<tt>i32 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i32 @llvm.ctpop.i29(i29 %val)</tt>.
3707</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3708
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]3709
3710<p>To learn how to add an intrinsic function, please see the
3711<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3712</p>
3713
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3714</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3715
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3716<!-- ======================================================================= -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3717<div class="doc_subsection">
3718 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
3719</div>
3720
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3721<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3722
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3723<p>Variable argument support is defined in LLVM with the <a
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]3724 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3725intrinsic functions. These functions are related to the similarly
3726named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3727
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3728<p>All of these functions operate on arguments that use a
3729target-specific value type "<tt>va_list</tt>". The LLVM assembly
3730language reference manual does not define what this type is, so all
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3731transformations should be prepared to handle these functions regardless of
3732the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3733
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]3734<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]3735instruction and the variable argument handling intrinsic functions are
3736used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3737
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3738<div class="doc_code">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3739<pre>
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3740define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3741 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3742 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3743 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3744 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3745
3746 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3747 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3748
3749 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3750 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3751 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3752 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3753 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3754
3755 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3756 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3757 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3758}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]3759
3760declare void @llvm.va_start(i8*)
3761declare void @llvm.va_copy(i8*, i8*)
3762declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3763</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3764</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3765
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]3766</div>
3767
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3768<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3769<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3770 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3771</div>
3772
3773
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3774<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3775<h5>Syntax:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3776<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3777<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3778<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
3779<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
3780href="#i_va_arg">va_arg</a></tt>.</p>
3781
3782<h5>Arguments:</h5>
3783
3784<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
3785
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3786<h5>Semantics:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3787
3788<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
3789macro available in C. In a target-dependent way, it initializes the
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3790<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]3791<tt>va_arg</tt> will produce the first variable argument passed to the function.
3792Unlike 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]3793last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3794
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3795</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3796
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3797<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3798<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3799 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3800</div>
3801
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3802<div class="doc_text">
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3803<h5>Syntax:</h5>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3804<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3805<h5>Overview:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3806
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3807<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3808which 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]3809or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3810
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3811<h5>Arguments:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3812
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3813<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]3814
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3815<h5>Semantics:</h5>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3816
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3817<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]3818macro available in C. In a target-dependent way, it destroys the
3819<tt>va_list</tt> element to which the argument points. Calls to <a
3820href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
3821<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
3822<tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]3823
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3824</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3825
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3826<!-- _______________________________________________________________________ -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3827<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3828 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3829</div>
3830
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3831<div class="doc_text">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3832
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3833<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3834
3835<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3836 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3837</pre>
3838
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3839<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3840
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3841<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
3842from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3843
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3844<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3845
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]3846<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]3847The 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]3848
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3849
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]3850<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3851
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]3852<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
3853macro available in C. In a target-dependent way, it copies the source
3854<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
3855intrinsic is necessary because the <tt><a href="#int_va_start">
3856llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
3857example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3858
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3859</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]3860
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]3861<!-- ======================================================================= -->
3862<div class="doc_subsection">
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3863 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
3864</div>
3865
3866<div class="doc_text">
3867
3868<p>
3869LLVM support for <a href="GarbageCollection.html">Accurate Garbage
3870Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3871These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3872stack</a>, as well as garbage collector implementations that require <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3873href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3874Front-ends for type-safe garbage collected languages should generate these
3875intrinsics to make use of the LLVM garbage collectors. For more details, see <a
3876href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
3877</p>
3878</div>
3879
3880<!-- _______________________________________________________________________ -->
3881<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3882 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3883</div>
3884
3885<div class="doc_text">
3886
3887<h5>Syntax:</h5>
3888
3889<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3890 declare void @llvm.gcroot(&lt;ty&gt;** %ptrloc, &lt;ty2&gt;* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3891</pre>
3892
3893<h5>Overview:</h5>
3894
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]3895<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]3896the code generator, and allows some metadata to be associated with it.</p>
3897
3898<h5>Arguments:</h5>
3899
3900<p>The first argument specifies the address of a stack object that contains the
3901root pointer. The second pointer (which must be either a constant or a global
3902value address) contains the meta-data to be associated with the root.</p>
3903
3904<h5>Semantics:</h5>
3905
3906<p>At runtime, a call to this intrinsics stores a null pointer into the "ptrloc"
3907location. At compile-time, the code generator generates information to allow
3908the runtime to find the pointer at GC safe points.
3909</p>
3910
3911</div>
3912
3913
3914<!-- _______________________________________________________________________ -->
3915<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3916 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3917</div>
3918
3919<div class="doc_text">
3920
3921<h5>Syntax:</h5>
3922
3923<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3924 declare i8 * @llvm.gcread(i8 * %ObjPtr, i8 ** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3925</pre>
3926
3927<h5>Overview:</h5>
3928
3929<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
3930locations, allowing garbage collector implementations that require read
3931barriers.</p>
3932
3933<h5>Arguments:</h5>
3934
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]3935<p>The second argument is the address to read from, which should be an address
3936allocated from the garbage collector. The first object is a pointer to the
3937start of the referenced object, if needed by the language runtime (otherwise
3938null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3939
3940<h5>Semantics:</h5>
3941
3942<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
3943instruction, but may be replaced with substantially more complex code by the
3944garbage collector runtime, as needed.</p>
3945
3946</div>
3947
3948
3949<!-- _______________________________________________________________________ -->
3950<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]3951 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3952</div>
3953
3954<div class="doc_text">
3955
3956<h5>Syntax:</h5>
3957
3958<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]3959 declare void @llvm.gcwrite(i8 * %P1, i8 * %Obj, i8 ** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3960</pre>
3961
3962<h5>Overview:</h5>
3963
3964<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
3965locations, allowing garbage collector implementations that require write
3966barriers (such as generational or reference counting collectors).</p>
3967
3968<h5>Arguments:</h5>
3969
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]3970<p>The first argument is the reference to store, the second is the start of the
3971object to store it to, and the third is the address of the field of Obj to
3972store to. If the runtime does not require a pointer to the object, Obj may be
3973null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]3974
3975<h5>Semantics:</h5>
3976
3977<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
3978instruction, but may be replaced with substantially more complex code by the
3979garbage collector runtime, as needed.</p>
3980
3981</div>
3982
3983
3984
3985<!-- ======================================================================= -->
3986<div class="doc_subsection">
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]3987 <a name="int_codegen">Code Generator Intrinsics</a>
3988</div>
3989
3990<div class="doc_text">
3991<p>
3992These intrinsics are provided by LLVM to expose special features that may only
3993be implemented with code generator support.
3994</p>
3995
3996</div>
3997
3998<!-- _______________________________________________________________________ -->
3999<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4000 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4001</div>
4002
4003<div class="doc_text">
4004
4005<h5>Syntax:</h5>
4006<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4007 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4008</pre>
4009
4010<h5>Overview:</h5>
4011
4012<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4013The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4014target-specific value indicating the return address of the current function
4015or one of its callers.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4016</p>
4017
4018<h5>Arguments:</h5>
4019
4020<p>
4021The argument to this intrinsic indicates which function to return the address
4022for. Zero indicates the calling function, one indicates its caller, etc. The
4023argument is <b>required</b> to be a constant integer value.
4024</p>
4025
4026<h5>Semantics:</h5>
4027
4028<p>
4029The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4030the return address of the specified call frame, or zero if it cannot be
4031identified. The value returned by this intrinsic is likely to be incorrect or 0
4032for arguments other than zero, so it should only be used for debugging purposes.
4033</p>
4034
4035<p>
4036Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4037aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4038source-language caller.
4039</p>
4040</div>
4041
4042
4043<!-- _______________________________________________________________________ -->
4044<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4045 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4046</div>
4047
4048<div class="doc_text">
4049
4050<h5>Syntax:</h5>
4051<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4052 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4053</pre>
4054
4055<h5>Overview:</h5>
4056
4057<p>
Chris Lattner32b5d712006-10-15 20:05:59 +0000[diff] [blame]4058The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4059target-specific frame pointer value for the specified stack frame.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4060</p>
4061
4062<h5>Arguments:</h5>
4063
4064<p>
4065The argument to this intrinsic indicates which function to return the frame
4066pointer for. Zero indicates the calling function, one indicates its caller,
4067etc. The argument is <b>required</b> to be a constant integer value.
4068</p>
4069
4070<h5>Semantics:</h5>
4071
4072<p>
4073The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4074the frame address of the specified call frame, or zero if it cannot be
4075identified. The value returned by this intrinsic is likely to be incorrect or 0
4076for arguments other than zero, so it should only be used for debugging purposes.
4077</p>
4078
4079<p>
4080Note that calling this intrinsic does not prevent function inlining or other
Chris Lattnerb40bb382005-03-07 20:30:51 +0000[diff] [blame]4081aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4082source-language caller.
4083</p>
4084</div>
4085
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4086<!-- _______________________________________________________________________ -->
4087<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4088 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4089</div>
4090
4091<div class="doc_text">
4092
4093<h5>Syntax:</h5>
4094<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4095 declare i8 *@llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4096</pre>
4097
4098<h5>Overview:</h5>
4099
4100<p>
4101The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4102the function stack, for use with <a href="#int_stackrestore">
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4103<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4104features like scoped automatic variable sized arrays in C99.
4105</p>
4106
4107<h5>Semantics:</h5>
4108
4109<p>
4110This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4111href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4112<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4113<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4114state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4115practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4116that were allocated after the <tt>llvm.stacksave</tt> was executed.
4117</p>
4118
4119</div>
4120
4121<!-- _______________________________________________________________________ -->
4122<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4123 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4124</div>
4125
4126<div class="doc_text">
4127
4128<h5>Syntax:</h5>
4129<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4130 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4131</pre>
4132
4133<h5>Overview:</h5>
4134
4135<p>
4136The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4137the function stack to the state it was in when the corresponding <a
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4138href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4139useful for implementing language features like scoped automatic variable sized
4140arrays in C99.
4141</p>
4142
4143<h5>Semantics:</h5>
4144
4145<p>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4146See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]4147</p>
4148
4149</div>
4150
4151
4152<!-- _______________________________________________________________________ -->
4153<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4154 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4155</div>
4156
4157<div class="doc_text">
4158
4159<h5>Syntax:</h5>
4160<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4161 declare void @llvm.prefetch(i8 * &lt;address&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4162 i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4163</pre>
4164
4165<h5>Overview:</h5>
4166
4167
4168<p>
4169The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4170a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4171no
4172effect on the behavior of the program but can change its performance
Chris Lattner2a615362005-02-28 19:47:14 +0000[diff] [blame]4173characteristics.
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4174</p>
4175
4176<h5>Arguments:</h5>
4177
4178<p>
4179<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4180determining if the fetch should be for a read (0) or write (1), and
4181<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattneraeffb4a2005-03-07 20:31:38 +0000[diff] [blame]4182locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]4183<tt>locality</tt> arguments must be constant integers.
4184</p>
4185
4186<h5>Semantics:</h5>
4187
4188<p>
4189This intrinsic does not modify the behavior of the program. In particular,
4190prefetches cannot trap and do not produce a value. On targets that support this
4191intrinsic, the prefetch can provide hints to the processor cache for better
4192performance.
4193</p>
4194
4195</div>
4196
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4197<!-- _______________________________________________________________________ -->
4198<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4199 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4200</div>
4201
4202<div class="doc_text">
4203
4204<h5>Syntax:</h5>
4205<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4206 declare void @llvm.pcmarker( i32 &lt;id&gt; )
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4207</pre>
4208
4209<h5>Overview:</h5>
4210
4211
4212<p>
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4213The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
4214(PC) in a region of
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4215code to simulators and other tools. The method is target specific, but it is
4216expected that the marker will use exported symbols to transmit the PC of the marker.
Jeff Cohen25d4f7e2005-11-11 02:15:27 +0000[diff] [blame]4217The marker makes no guarantees that it will remain with any specific instruction
Chris Lattnerd07c3f42005-11-15 06:07:55 +0000[diff] [blame]4218after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb3e7afd2006-03-24 07:16:10 +0000[diff] [blame]4219optimizations. The intended use is to be inserted after optimizations to allow
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]4220correlations of simulation runs.
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]4221</p>
4222
4223<h5>Arguments:</h5>
4224
4225<p>
4226<tt>id</tt> is a numerical id identifying the marker.
4227</p>
4228
4229<h5>Semantics:</h5>
4230
4231<p>
4232This intrinsic does not modify the behavior of the program. Backends that do not
4233support this intrinisic may ignore it.
4234</p>
4235
4236</div>
4237
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4238<!-- _______________________________________________________________________ -->
4239<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4240 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4241</div>
4242
4243<div class="doc_text">
4244
4245<h5>Syntax:</h5>
4246<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4247 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]4248</pre>
4249
4250<h5>Overview:</h5>
4251
4252
4253<p>
4254The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4255counter register (or similar low latency, high accuracy clocks) on those targets
4256that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4257As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4258should only be used for small timings.
4259</p>
4260
4261<h5>Semantics:</h5>
4262
4263<p>
4264When directly supported, reading the cycle counter should not modify any memory.
4265Implementations are allowed to either return a application specific value or a
4266system wide value. On backends without support, this is lowered to a constant 0.
4267</p>
4268
4269</div>
4270
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4271<!-- ======================================================================= -->
4272<div class="doc_subsection">
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4273 <a name="int_libc">Standard C Library Intrinsics</a>
4274</div>
4275
4276<div class="doc_text">
4277<p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4278LLVM provides intrinsics for a few important standard C library functions.
4279These intrinsics allow source-language front-ends to pass information about the
4280alignment of the pointer arguments to the code generator, providing opportunity
4281for more efficient code generation.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4282</p>
4283
4284</div>
4285
4286<!-- _______________________________________________________________________ -->
4287<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4288 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4289</div>
4290
4291<div class="doc_text">
4292
4293<h5>Syntax:</h5>
4294<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4295 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4296 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4297 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4298 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4299</pre>
4300
4301<h5>Overview:</h5>
4302
4303<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4304The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4305location to the destination location.
4306</p>
4307
4308<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4309Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
4310intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4311</p>
4312
4313<h5>Arguments:</h5>
4314
4315<p>
4316The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4317the source. The third argument is an integer argument
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4318specifying the number of bytes to copy, and the fourth argument is the alignment
4319of the source and destination locations.
4320</p>
4321
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4322<p>
4323If 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]4324the caller guarantees that both the source and destination pointers are aligned
4325to that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4326</p>
4327
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4328<h5>Semantics:</h5>
4329
4330<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4331The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]4332location to the destination location, which are not allowed to overlap. It
4333copies "len" bytes of memory over. If the argument is known to be aligned to
4334some boundary, this can be specified as the fourth argument, otherwise it should
4335be set to 0 or 1.
4336</p>
4337</div>
4338
4339
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4340<!-- _______________________________________________________________________ -->
4341<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4342 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4343</div>
4344
4345<div class="doc_text">
4346
4347<h5>Syntax:</h5>
4348<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4349 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4350 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4351 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4352 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4353</pre>
4354
4355<h5>Overview:</h5>
4356
4357<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4358The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
4359location to the destination location. It is similar to the
4360'<tt>llvm.memcmp</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4361</p>
4362
4363<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4364Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
4365intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4366</p>
4367
4368<h5>Arguments:</h5>
4369
4370<p>
4371The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4372the source. The third argument is an integer argument
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4373specifying the number of bytes to copy, and the fourth argument is the alignment
4374of the source and destination locations.
4375</p>
4376
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4377<p>
4378If 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]4379the caller guarantees that the source and destination pointers are aligned to
4380that boundary.
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]4381</p>
4382
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4383<h5>Semantics:</h5>
4384
4385<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4386The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]4387location to the destination location, which may overlap. It
4388copies "len" bytes of memory over. If the argument is known to be aligned to
4389some boundary, this can be specified as the fourth argument, otherwise it should
4390be set to 0 or 1.
4391</p>
4392</div>
4393
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4394
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4395<!-- _______________________________________________________________________ -->
4396<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4397 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4398</div>
4399
4400<div class="doc_text">
4401
4402<h5>Syntax:</h5>
4403<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4404 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4405 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4406 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4407 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4408</pre>
4409
4410<h5>Overview:</h5>
4411
4412<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4413The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4414byte value.
4415</p>
4416
4417<p>
4418Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
4419does not return a value, and takes an extra alignment argument.
4420</p>
4421
4422<h5>Arguments:</h5>
4423
4424<p>
4425The first argument is a pointer to the destination to fill, the second is the
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4426byte value to fill it with, the third argument is an integer
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4427argument specifying the number of bytes to fill, and the fourth argument is the
4428known alignment of destination location.
4429</p>
4430
4431<p>
4432If 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]4433the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4434</p>
4435
4436<h5>Semantics:</h5>
4437
4438<p>
Chris Lattner5b310c32006-03-03 00:07:20 +0000[diff] [blame]4439The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
4440the
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]4441destination location. If the argument is known to be aligned to some boundary,
4442this can be specified as the fourth argument, otherwise it should be set to 0 or
44431.
4444</p>
4445</div>
4446
4447
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4448<!-- _______________________________________________________________________ -->
4449<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4450 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4451</div>
4452
4453<div class="doc_text">
4454
4455<h5>Syntax:</h5>
4456<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4457 declare float @llvm.sqrt.f32(float %Val)
4458 declare double @llvm.sqrt.f64(double %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4459</pre>
4460
4461<h5>Overview:</h5>
4462
4463<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4464The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]4465returning the same value as the libm '<tt>sqrt</tt>' function would. Unlike
4466<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
4467negative numbers (which allows for better optimization).
4468</p>
4469
4470<h5>Arguments:</h5>
4471
4472<p>
4473The argument and return value are floating point numbers of the same type.
4474</p>
4475
4476<h5>Semantics:</h5>
4477
4478<p>
4479This function returns the sqrt of the specified operand if it is a positive
4480floating point number.
4481</p>
4482</div>
4483
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4484<!-- _______________________________________________________________________ -->
4485<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4486 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4487</div>
4488
4489<div class="doc_text">
4490
4491<h5>Syntax:</h5>
4492<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4493 declare float @llvm.powi.f32(float %Val, i32 %power)
4494 declare double @llvm.powi.f64(double %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]4495</pre>
4496
4497<h5>Overview:</h5>
4498
4499<p>
4500The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
4501specified (positive or negative) power. The order of evaluation of
4502multiplications is not defined.
4503</p>
4504
4505<h5>Arguments:</h5>
4506
4507<p>
4508The second argument is an integer power, and the first is a value to raise to
4509that power.
4510</p>
4511
4512<h5>Semantics:</h5>
4513
4514<p>
4515This function returns the first value raised to the second power with an
4516unspecified sequence of rounding operations.</p>
4517</div>
4518
4519
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4520<!-- ======================================================================= -->
4521<div class="doc_subsection">
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4522 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4523</div>
4524
4525<div class="doc_text">
4526<p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4527LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4528These allow efficient code generation for some algorithms.
4529</p>
4530
4531</div>
4532
4533<!-- _______________________________________________________________________ -->
4534<div class="doc_subsubsection">
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4535 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4536</div>
4537
4538<div class="doc_text">
4539
4540<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4541<p>This is an overloaded intrinsic function. You can use bswap on any integer
4542type that is an even number of bytes (i.e. BitWidth % 16 == 0). Note the suffix
4543that includes the type for the result and the operand.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4544<pre>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4545 declare i16 @llvm.bswap.i16.i16(i16 &lt;id&gt;)
4546 declare i32 @llvm.bswap.i32.i32(i32 &lt;id&gt;)
Reid Spencer543ab1d2007-04-02 00:19:52 +0000[diff] [blame]4547 declare i64 @llvm.bswap.i64.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4548</pre>
4549
4550<h5>Overview:</h5>
4551
4552<p>
Reid Spencer338ea092007-04-02 02:25:19 +0000[diff] [blame]4553The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4554values with an even number of bytes (positive multiple of 16 bits). These are
4555useful for performing operations on data that is not in the target's native
4556byte order.
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4557</p>
4558
4559<h5>Semantics:</h5>
4560
4561<p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4562The <tt>llvm.bswap.16.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4563and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
4564intrinsic returns an i32 value that has the four bytes of the input i32
4565swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4566i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48.i48</tt>,
4567<tt>llvm.bswap.i64.i64</tt> and other intrinsics extend this concept to
4568additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]4569</p>
4570
4571</div>
4572
4573<!-- _______________________________________________________________________ -->
4574<div class="doc_subsubsection">
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4575 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4576</div>
4577
4578<div class="doc_text">
4579
4580<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4581<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
4582width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4583<pre>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4584 declare i32 @llvm.ctpop.i8 (i8 &lt;src&gt;)
4585 declare i32 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4586 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4587 declare i32 @llvm.ctpop.i64(i64 &lt;src&gt;)
4588 declare i32 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4589</pre>
4590
4591<h5>Overview:</h5>
4592
4593<p>
Chris Lattnerec6cb612006-01-16 22:38:59 +0000[diff] [blame]4594The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
4595value.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4596</p>
4597
4598<h5>Arguments:</h5>
4599
4600<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4601The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4602integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4603</p>
4604
4605<h5>Semantics:</h5>
4606
4607<p>
4608The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
4609</p>
4610</div>
4611
4612<!-- _______________________________________________________________________ -->
4613<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4614 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4615</div>
4616
4617<div class="doc_text">
4618
4619<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4620<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
4621integer bit width. Not all targets support all bit widths however.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4622<pre>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4623 declare i32 @llvm.ctlz.i8 (i8 &lt;src&gt;)
4624 declare i32 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4625 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4626 declare i32 @llvm.ctlz.i64(i64 &lt;src&gt;)
4627 declare i32 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4628</pre>
4629
4630<h5>Overview:</h5>
4631
4632<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4633The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
4634leading zeros in a variable.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4635</p>
4636
4637<h5>Arguments:</h5>
4638
4639<p>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]4640The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4641integer type. The return type must match the argument type.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4642</p>
4643
4644<h5>Semantics:</h5>
4645
4646<p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4647The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
4648in 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]4649of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]4650</p>
4651</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]4652
4653
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4654
4655<!-- _______________________________________________________________________ -->
4656<div class="doc_subsubsection">
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]4657 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4658</div>
4659
4660<div class="doc_text">
4661
4662<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4663<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
4664integer bit width. Not all targets support all bit widths however.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4665<pre>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4666 declare i32 @llvm.cttz.i8 (i8 &lt;src&gt;)
4667 declare i32 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]4668 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]4669 declare i32 @llvm.cttz.i64(i64 &lt;src&gt;)
4670 declare i32 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4671</pre>
4672
4673<h5>Overview:</h5>
4674
4675<p>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]4676The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
4677trailing zeros.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4678</p>
4679
4680<h5>Arguments:</h5>
4681
4682<p>
4683The only argument is the value to be counted. The argument may be of any
Reid Spencera5173382007-01-04 16:43:23 +0000[diff] [blame]4684integer type. The return type must match the argument type.
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]4685</p>
4686
4687<h5>Semantics:</h5>
4688
4689<p>
4690The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
4691in a variable. If the src == 0 then the result is the size in bits of the type
4692of src. For example, <tt>llvm.cttz(2) = 1</tt>.
4693</p>
4694</div>
4695
Reid Spencer497d93e2007-04-01 08:27:01 +0000[diff] [blame]4696<!-- _______________________________________________________________________ -->
4697<div class="doc_subsubsection">
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4698 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4699</div>
4700
4701<div class="doc_text">
4702
4703<h5>Syntax:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4704<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4705on any integer bit width.
4706<pre>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4707 declare i17 @llvm.part.select.i17.i17 (i17 %val, i32 %loBit, i32 %hiBit)
4708 declare i29 @llvm.part.select.i29.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4709</pre>
4710
4711<h5>Overview:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4712<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4713range of bits from an integer value and returns them in the same bit width as
4714the original value.</p>
4715
4716<h5>Arguments:</h5>
4717<p>The first argument, <tt>%val</tt> and the result may be integer types of
4718any bit width but they must have the same bit width. The second and third
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4719arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4720
4721<h5>Semantics:</h5>
Reid Spencerbeacf662007-04-10 02:51:31 +0000[diff] [blame]4722<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]4723of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
4724<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
4725operates in forward mode.</p>
4726<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
4727right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4728only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
4729<ol>
4730 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
4731 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
4732 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
4733 to determine the number of bits to retain.</li>
4734 <li>A mask of the retained bits is created by shifting a -1 value.</li>
4735 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
4736</ol>
Reid Spencerd6a85b52007-05-14 16:14:57 +0000[diff] [blame]4737<p>In reverse mode, a similar computation is made except that the bits are
4738returned in the reverse order. So, for example, if <tt>X</tt> has the value
4739<tt>i16 0x0ACF (101011001111)</tt> and we apply
4740<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
4741<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencera13ba7d2007-04-01 19:00:37 +0000[diff] [blame]4742</div>
4743
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]4744<div class="doc_subsubsection">
4745 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
4746</div>
4747
4748<div class="doc_text">
4749
4750<h5>Syntax:</h5>
4751<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
4752on any integer bit width.
4753<pre>
4754 declare i17 @llvm.part.set.i17.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
4755 declare i29 @llvm.part.set.i29.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
4756</pre>
4757
4758<h5>Overview:</h5>
4759<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
4760of bits in an integer value with another integer value. It returns the integer
4761with the replaced bits.</p>
4762
4763<h5>Arguments:</h5>
4764<p>The first argument, <tt>%val</tt> and the result may be integer types of
4765any bit width but they must have the same bit width. <tt>%val</tt> is the value
4766whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
4767integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
4768type since they specify only a bit index.</p>
4769
4770<h5>Semantics:</h5>
4771<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
4772of operation: forwards and reverse. If <tt>%lo</tt> is greater than
4773<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
4774operates in forward mode.</p>
4775<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
4776truncating it down to the size of the replacement area or zero extending it
4777up to that size.</p>
4778<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
4779are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
4780in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
4781to the <tt>%hi</tt>th bit.
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]4782<p>In reverse mode, a similar computation is made except that the bits are
4783reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
4784<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]4785<h5>Examples:</h5>
4786<pre>
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]4787 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencerc6749c42007-05-14 16:50:20 +0000[diff] [blame]4788 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
4789 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
4790 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerf0dbf642007-04-12 01:03:03 +0000[diff] [blame]4791 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]4792</pre>
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]4793</div>
4794
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]4795<!-- ======================================================================= -->
4796<div class="doc_subsection">
4797 <a name="int_debugger">Debugger Intrinsics</a>
4798</div>
4799
4800<div class="doc_text">
4801<p>
4802The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
4803are described in the <a
4804href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
4805Debugging</a> document.
4806</p>
4807</div>
4808
4809
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]4810<!-- ======================================================================= -->
4811<div class="doc_subsection">
4812 <a name="int_eh">Exception Handling Intrinsics</a>
4813</div>
4814
4815<div class="doc_text">
4816<p> The LLVM exception handling intrinsics (which all start with
4817<tt>llvm.eh.</tt> prefix), are described in the <a
4818href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
4819Handling</a> document. </p>
4820</div>
4821
4822
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4823<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4824<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]4825<address>
4826 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
4827 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
4828 <a href="http://validator.w3.org/check/referer"><img
4829 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
4830
4831 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer05fe4b02006-03-14 05:39:39 +0000[diff] [blame]4832 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]4833 Last modified: $Date$
4834</address>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4835</body>
4836</html>