Gitiles
Code Review Sign In
gerrit-public.fairphone.software / toolchain / llvm-project / 16cbbe43d80387bf1dfa580b6c3ae7a352f91a7c / . / llvm / docs / LangRef.html
blob: 2589771915f1cd1349b5c96da245c9d43da26b9b [file] [log] [blame]
Misha Brukmanc501f552004-03-01 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 Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3<html>
4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencercb84e432004-08-26 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 Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman76307852003-11-08 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 Lattner6af02f32004-12-09 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>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
27 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
28 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
29 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
30 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
31 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
32 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
33 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
34 <li><a href="#linkage_linkonce">'<tt>linkonce_odr</tt>' Linkage</a></li>
35 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
36 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
37 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
38 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]39 </ol>
40 </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]41 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]42 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]43 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]44 <li><a href="#functionstructure">Functions</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]45 <li><a href="#aliasstructure">Aliases</a></li>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]46 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]47 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]48 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]49 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]50 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]51 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]52 </ol>
53 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]54 <li><a href="#typesystem">Type System</a>
55 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]56 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]57 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]58 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]59 <li><a href="#t_floating">Floating Point Types</a></li>
60 <li><a href="#t_void">Void Type</a></li>
61 <li><a href="#t_label">Label Type</a></li>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]62 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]63 </ol>
64 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]65 <li><a href="#t_derived">Derived Types</a>
66 <ol>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]67 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]68 <li><a href="#t_array">Array Type</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]69 <li><a href="#t_function">Function Type</a></li>
70 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]71 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]72 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]73 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]74 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]75 </ol>
76 </li>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]77 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]78 </ol>
79 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]80 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]81 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]82 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]83 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]84 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
85 <li><a href="#undefvalues">Undefined Values</a></li>
86 <li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]87 <li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]88 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]89 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]90 <li><a href="#othervalues">Other Values</a>
91 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]92 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]93 </ol>
94 </li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]95 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
96 <ol>
97 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]98 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
99 Global Variable</a></li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]100 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
101 Global Variable</a></li>
102 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
103 Global Variable</a></li>
104 </ol>
105 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]106 <li><a href="#instref">Instruction Reference</a>
107 <ol>
108 <li><a href="#terminators">Terminator Instructions</a>
109 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]110 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
111 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]112 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
113 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]114 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]115 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]116 </ol>
117 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]118 <li><a href="#binaryops">Binary Operations</a>
119 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]120 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]121 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]122 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]123 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]124 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]125 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]126 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
127 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
128 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]129 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
130 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
131 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]132 </ol>
133 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]134 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
135 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]136 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
137 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
138 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]139 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]140 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]141 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]142 </ol>
143 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]144 <li><a href="#vectorops">Vector Operations</a>
145 <ol>
146 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
147 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
148 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]149 </ol>
150 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]151 <li><a href="#aggregateops">Aggregate Operations</a>
152 <ol>
153 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
154 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
155 </ol>
156 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]157 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]158 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]159 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
160 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
161 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]162 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
163 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
164 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]165 </ol>
166 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]167 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]168 <ol>
169 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
170 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
171 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
172 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
173 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]174 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
175 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
176 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
177 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]178 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
179 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]180 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]181 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]182 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]183 <li><a href="#otherops">Other Operations</a>
184 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]185 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
186 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]187 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]188 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]189 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]190 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]191 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]192 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]193 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]194 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]195 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]196 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]197 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
198 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]199 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
200 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
201 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]202 </ol>
203 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]204 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
205 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]206 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
207 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
208 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]209 </ol>
210 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]211 <li><a href="#int_codegen">Code Generator Intrinsics</a>
212 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]213 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
214 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
215 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
216 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
217 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
218 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
219 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]220 </ol>
221 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]222 <li><a href="#int_libc">Standard C Library Intrinsics</a>
223 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]224 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
225 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
226 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
227 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
228 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]229 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
230 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
231 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]232 </ol>
233 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]234 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]235 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]236 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]237 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
238 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
239 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]240 </ol>
241 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]242 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
243 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]244 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
245 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
246 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
247 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
248 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]249 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]250 </ol>
251 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]252 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]253 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]254 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]255 <ol>
256 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]257 </ol>
258 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]259 <li><a href="#int_atomics">Atomic intrinsics</a>
260 <ol>
261 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
262 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
263 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
264 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
265 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
266 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
267 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
268 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
269 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
270 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
271 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
272 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
273 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
274 </ol>
275 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]276 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]277 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]278 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]279 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]280 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]281 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]282 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]283 '<tt>llvm.trap</tt>' Intrinsic</a></li>
284 <li><a href="#int_stackprotector">
285 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]286 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]287 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]288 </ol>
289 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]290</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]291
292<div class="doc_author">
293 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
294 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]295</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]296
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]297<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]298<div class="doc_section"> <a name="abstract">Abstract </a></div>
299<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]300
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]301<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]302
303<p>This document is a reference manual for the LLVM assembly language. LLVM is
304 a Static Single Assignment (SSA) based representation that provides type
305 safety, low-level operations, flexibility, and the capability of representing
306 'all' high-level languages cleanly. It is the common code representation
307 used throughout all phases of the LLVM compilation strategy.</p>
308
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]309</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]310
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]311<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]312<div class="doc_section"> <a name="introduction">Introduction</a> </div>
313<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]314
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]315<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]316
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]317<p>The LLVM code representation is designed to be used in three different forms:
318 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
319 for fast loading by a Just-In-Time compiler), and as a human readable
320 assembly language representation. This allows LLVM to provide a powerful
321 intermediate representation for efficient compiler transformations and
322 analysis, while providing a natural means to debug and visualize the
323 transformations. The three different forms of LLVM are all equivalent. This
324 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]325
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]326<p>The LLVM representation aims to be light-weight and low-level while being
327 expressive, typed, and extensible at the same time. It aims to be a
328 "universal IR" of sorts, by being at a low enough level that high-level ideas
329 may be cleanly mapped to it (similar to how microprocessors are "universal
330 IR's", allowing many source languages to be mapped to them). By providing
331 type information, LLVM can be used as the target of optimizations: for
332 example, through pointer analysis, it can be proven that a C automatic
333 variable is never accessed outside of the current function... allowing it to
334 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]335
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]336</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]337
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]338<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]339<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]340
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]341<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]342
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]343<p>It is important to note that this document describes 'well formed' LLVM
344 assembly language. There is a difference between what the parser accepts and
345 what is considered 'well formed'. For example, the following instruction is
346 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]347
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]348<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]349<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]350%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]351</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]352</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]353
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]354<p>...because the definition of <tt>%x</tt> does not dominate all of its
355 uses. The LLVM infrastructure provides a verification pass that may be used
356 to verify that an LLVM module is well formed. This pass is automatically run
357 by the parser after parsing input assembly and by the optimizer before it
358 outputs bitcode. The violations pointed out by the verifier pass indicate
359 bugs in transformation passes or input to the parser.</p>
360
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]361</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]362
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]363<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]364
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]365<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]366<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]367<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]368
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]369<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]370
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]371<p>LLVM identifiers come in two basic types: global and local. Global
372 identifiers (functions, global variables) begin with the <tt>'@'</tt>
373 character. Local identifiers (register names, types) begin with
374 the <tt>'%'</tt> character. Additionally, there are three different formats
375 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]376
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]377<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]378 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]379 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
380 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
381 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
382 other characters in their names can be surrounded with quotes. Special
383 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
384 ASCII code for the character in hexadecimal. In this way, any character
385 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]386
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]387 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]388 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]389
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]390 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]391 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]392</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]393
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]394<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]395 don't need to worry about name clashes with reserved words, and the set of
396 reserved words may be expanded in the future without penalty. Additionally,
397 unnamed identifiers allow a compiler to quickly come up with a temporary
398 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]399
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]400<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]401 languages. There are keywords for different opcodes
402 ('<tt><a href="#i_add">add</a></tt>',
403 '<tt><a href="#i_bitcast">bitcast</a></tt>',
404 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
405 ('<tt><a href="#t_void">void</a></tt>',
406 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
407 reserved words cannot conflict with variable names, because none of them
408 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]409
410<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]411 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]412
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]413<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]414
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]415<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]416<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]417%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]418</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]419</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]420
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]421<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]422
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]423<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]424<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]425%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]426</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]427</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]428
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]429<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]430
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]431<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]432<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]433<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
434<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
435%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]436</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]437</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]438
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]439<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
440 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]441
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]442<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]443 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]444 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]445
446 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]447 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]448
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]449 <li>Unnamed temporaries are numbered sequentially</li>
450</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]451
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]452<p>...and it also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]453 demonstrating instructions, we will follow an instruction with a comment that
454 defines the type and name of value produced. Comments are shown in italic
455 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]456
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]457</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]458
459<!-- *********************************************************************** -->
460<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
461<!-- *********************************************************************** -->
462
463<!-- ======================================================================= -->
464<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
465</div>
466
467<div class="doc_text">
468
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]469<p>LLVM programs are composed of "Module"s, each of which is a translation unit
470 of the input programs. Each module consists of functions, global variables,
471 and symbol table entries. Modules may be combined together with the LLVM
472 linker, which merges function (and global variable) definitions, resolves
473 forward declarations, and merges symbol table entries. Here is an example of
474 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]475
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]476<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]477<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]478<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
479 href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]480
481<i>; External declaration of the puts function</i>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]482<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]483
484<i>; Definition of main function</i>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]485define i32 @main() { <i>; i32()* </i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]486 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]487 %cast210 = <a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]488 href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]489
490 <i>; Call puts function to write out the string to stdout...</i>
491 <a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]492 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]493 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]494 href="#i_ret">ret</a> i32 0<br>}<br>
495</pre>
496</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]497
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]498<p>This example is made up of a <a href="#globalvars">global variable</a> named
499 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function, and
500 a <a href="#functionstructure">function definition</a> for
501 "<tt>main</tt>".</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]502
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]503<p>In general, a module is made up of a list of global values, where both
504 functions and global variables are global values. Global values are
505 represented by a pointer to a memory location (in this case, a pointer to an
506 array of char, and a pointer to a function), and have one of the
507 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]508
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]509</div>
510
511<!-- ======================================================================= -->
512<div class="doc_subsection">
513 <a name="linkage">Linkage Types</a>
514</div>
515
516<div class="doc_text">
517
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]518<p>All Global Variables and Functions have one of the following types of
519 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]520
521<dl>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]522 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]523 <dd>Global values with private linkage are only directly accessible by objects
524 in the current module. In particular, linking code into a module with an
525 private global value may cause the private to be renamed as necessary to
526 avoid collisions. Because the symbol is private to the module, all
527 references can be updated. This doesn't show up in any symbol table in the
528 object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]529
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]530 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt>: </dt>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]531 <dd>Similar to private, but the symbol is passed through the assembler and
532 removed by the linker after evaluation.</dd>
533
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]534 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]535 <dd>Similar to private, but the value shows as a local symbol
536 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
537 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]538
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]539 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt>: </dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]540 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]541 into the object file corresponding to the LLVM module. They exist to
542 allow inlining and other optimizations to take place given knowledge of
543 the definition of the global, which is known to be somewhere outside the
544 module. Globals with <tt>available_externally</tt> linkage are allowed to
545 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
546 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]547
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]548 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]549 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]550 the same name when linkage occurs. This is typically used to implement
551 inline functions, templates, or other code which must be generated in each
552 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
553 allowed to be discarded.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]554
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]555 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]556 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
557 linkage, except that unreferenced <tt>common</tt> globals may not be
558 discarded. This is used for globals that may be emitted in multiple
559 translation units, but that are not guaranteed to be emitted into every
560 translation unit that uses them. One example of this is tentative
561 definitions in C, such as "<tt>int X;</tt>" at global scope.</dd>
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]562
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]563 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]564 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]565 that some targets may choose to emit different assembly sequences for them
566 for target-dependent reasons. This is used for globals that are declared
567 "weak" in C source code.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]568
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]569 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]570 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]571 pointer to array type. When two global variables with appending linkage
572 are linked together, the two global arrays are appended together. This is
573 the LLVM, typesafe, equivalent of having the system linker append together
574 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]575
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]576 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]577 <dd>The semantics of this linkage follow the ELF object file model: the symbol
578 is weak until linked, if not linked, the symbol becomes null instead of
579 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]580
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]581 <dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]582 <dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]583 <dd>Some languages allow differing globals to be merged, such as two functions
584 with different semantics. Other languages, such as <tt>C++</tt>, ensure
585 that only equivalent globals are ever merged (the "one definition rule" -
586 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
587 and <tt>weak_odr</tt> linkage types to indicate that the global will only
588 be merged with equivalent globals. These linkage types are otherwise the
589 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]590
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]591 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]592 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]593 visible, meaning that it participates in linkage and can be used to
594 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]595</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]596
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]597<p>The next two types of linkage are targeted for Microsoft Windows platform
598 only. They are designed to support importing (exporting) symbols from (to)
599 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]600
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]601<dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]602 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]603 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]604 or variable via a global pointer to a pointer that is set up by the DLL
605 exporting the symbol. On Microsoft Windows targets, the pointer name is
606 formed by combining <code>__imp_</code> and the function or variable
607 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]608
609 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]610 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]611 pointer to a pointer in a DLL, so that it can be referenced with the
612 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
613 name is formed by combining <code>__imp_</code> and the function or
614 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]615</dl>
616
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]617<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
618 another module defined a "<tt>.LC0</tt>" variable and was linked with this
619 one, one of the two would be renamed, preventing a collision. Since
620 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
621 declarations), they are accessible outside of the current module.</p>
622
623<p>It is illegal for a function <i>declaration</i> to have any linkage type
624 other than "externally visible", <tt>dllimport</tt>
625 or <tt>extern_weak</tt>.</p>
626
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]627<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]628 or <tt>weak_odr</tt> linkages.</p>
629
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]630</div>
631
632<!-- ======================================================================= -->
633<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]634 <a name="callingconv">Calling Conventions</a>
635</div>
636
637<div class="doc_text">
638
639<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]640 and <a href="#i_invoke">invokes</a> can all have an optional calling
641 convention specified for the call. The calling convention of any pair of
642 dynamic caller/callee must match, or the behavior of the program is
643 undefined. The following calling conventions are supported by LLVM, and more
644 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]645
646<dl>
647 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]648 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]649 specified) matches the target C calling conventions. This calling
650 convention supports varargs function calls and tolerates some mismatch in
651 the declared prototype and implemented declaration of the function (as
652 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]653
654 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]655 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]656 (e.g. by passing things in registers). This calling convention allows the
657 target to use whatever tricks it wants to produce fast code for the
658 target, without having to conform to an externally specified ABI
659 (Application Binary Interface). Implementations of this convention should
660 allow arbitrary <a href="CodeGenerator.html#tailcallopt">tail call
661 optimization</a> to be supported. This calling convention does not
662 support varargs and requires the prototype of all callees to exactly match
663 the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]664
665 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]666 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]667 as possible under the assumption that the call is not commonly executed.
668 As such, these calls often preserve all registers so that the call does
669 not break any live ranges in the caller side. This calling convention
670 does not support varargs and requires the prototype of all callees to
671 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]672
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]673 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]674 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]675 target-specific calling conventions to be used. Target specific calling
676 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]677</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]678
679<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]680 support Pascal conventions or any other well-known target-independent
681 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]682
683</div>
684
685<!-- ======================================================================= -->
686<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]687 <a name="visibility">Visibility Styles</a>
688</div>
689
690<div class="doc_text">
691
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]692<p>All Global Variables and Functions have one of the following visibility
693 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]694
695<dl>
696 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]697 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]698 that the declaration is visible to other modules and, in shared libraries,
699 means that the declared entity may be overridden. On Darwin, default
700 visibility means that the declaration is visible to other modules. Default
701 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]702
703 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]704 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]705 object if they are in the same shared object. Usually, hidden visibility
706 indicates that the symbol will not be placed into the dynamic symbol
707 table, so no other module (executable or shared library) can reference it
708 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]709
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]710 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]711 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]712 the dynamic symbol table, but that references within the defining module
713 will bind to the local symbol. That is, the symbol cannot be overridden by
714 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]715</dl>
716
717</div>
718
719<!-- ======================================================================= -->
720<div class="doc_subsection">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]721 <a name="namedtypes">Named Types</a>
722</div>
723
724<div class="doc_text">
725
726<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]727 it easier to read the IR and make the IR more condensed (particularly when
728 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]729
730<div class="doc_code">
731<pre>
732%mytype = type { %mytype*, i32 }
733</pre>
734</div>
735
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]736<p>You may give a name to any <a href="#typesystem">type</a> except
737 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
738 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]739
740<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]741 and that you can therefore specify multiple names for the same type. This
742 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
743 uses structural typing, the name is not part of the type. When printing out
744 LLVM IR, the printer will pick <em>one name</em> to render all types of a
745 particular shape. This means that if you have code where two different
746 source types end up having the same LLVM type, that the dumper will sometimes
747 print the "wrong" or unexpected type. This is an important design point and
748 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]749
750</div>
751
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]752<!-- ======================================================================= -->
753<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]754 <a name="globalvars">Global Variables</a>
755</div>
756
757<div class="doc_text">
758
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]759<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]760 instead of run-time. Global variables may optionally be initialized, may
761 have an explicit section to be placed in, and may have an optional explicit
762 alignment specified. A variable may be defined as "thread_local", which
763 means that it will not be shared by threads (each thread will have a
764 separated copy of the variable). A variable may be defined as a global
765 "constant," which indicates that the contents of the variable
766 will <b>never</b> be modified (enabling better optimization, allowing the
767 global data to be placed in the read-only section of an executable, etc).
768 Note that variables that need runtime initialization cannot be marked
769 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]770
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]771<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
772 constant, even if the final definition of the global is not. This capability
773 can be used to enable slightly better optimization of the program, but
774 requires the language definition to guarantee that optimizations based on the
775 'constantness' are valid for the translation units that do not include the
776 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]777
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]778<p>As SSA values, global variables define pointer values that are in scope
779 (i.e. they dominate) all basic blocks in the program. Global variables
780 always define a pointer to their "content" type because they describe a
781 region of memory, and all memory objects in LLVM are accessed through
782 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]783
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]784<p>A global variable may be declared to reside in a target-specific numbered
785 address space. For targets that support them, address spaces may affect how
786 optimizations are performed and/or what target instructions are used to
787 access the variable. The default address space is zero. The address space
788 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]789
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]790<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]791 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]792
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]793<p>An explicit alignment may be specified for a global. If not present, or if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]794 the alignment is set to zero, the alignment of the global is set by the
795 target to whatever it feels convenient. If an explicit alignment is
796 specified, the global is forced to have at least that much alignment. All
797 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]798
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]799<p>For example, the following defines a global in a numbered address space with
800 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]801
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]802<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]803<pre>
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]804@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]805</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]806</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]807
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]808</div>
809
810
811<!-- ======================================================================= -->
812<div class="doc_subsection">
813 <a name="functionstructure">Functions</a>
814</div>
815
816<div class="doc_text">
817
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]818<p>LLVM function definitions consist of the "<tt>define</tt>" keyord, an
819 optional <a href="#linkage">linkage type</a>, an optional
820 <a href="#visibility">visibility style</a>, an optional
821 <a href="#callingconv">calling convention</a>, a return type, an optional
822 <a href="#paramattrs">parameter attribute</a> for the return type, a function
823 name, a (possibly empty) argument list (each with optional
824 <a href="#paramattrs">parameter attributes</a>), optional
825 <a href="#fnattrs">function attributes</a>, an optional section, an optional
826 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
827 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]828
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]829<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
830 optional <a href="#linkage">linkage type</a>, an optional
831 <a href="#visibility">visibility style</a>, an optional
832 <a href="#callingconv">calling convention</a>, a return type, an optional
833 <a href="#paramattrs">parameter attribute</a> for the return type, a function
834 name, a possibly empty list of arguments, an optional alignment, and an
835 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]836
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]837<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]838 (Control Flow Graph) for the function. Each basic block may optionally start
839 with a label (giving the basic block a symbol table entry), contains a list
840 of instructions, and ends with a <a href="#terminators">terminator</a>
841 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]842
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]843<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]844 executed on entrance to the function, and it is not allowed to have
845 predecessor basic blocks (i.e. there can not be any branches to the entry
846 block of a function). Because the block can have no predecessors, it also
847 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]848
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]849<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]850 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]851
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]852<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]853 the alignment is set to zero, the alignment of the function is set by the
854 target to whatever it feels convenient. If an explicit alignment is
855 specified, the function is forced to have at least that much alignment. All
856 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]857
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]858<h5>Syntax:</h5>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]859<div class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]860<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]861define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]862 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
863 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
864 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
865 [<a href="#gc">gc</a>] { ... }
866</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]867</div>
868
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]869</div>
870
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]871<!-- ======================================================================= -->
872<div class="doc_subsection">
873 <a name="aliasstructure">Aliases</a>
874</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]875
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]876<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]877
878<p>Aliases act as "second name" for the aliasee value (which can be either
879 function, global variable, another alias or bitcast of global value). Aliases
880 may have an optional <a href="#linkage">linkage type</a>, and an
881 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]882
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]883<h5>Syntax:</h5>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]884<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]885<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]886@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]887</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]888</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]889
890</div>
891
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]892<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]893<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]894
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]895<div class="doc_text">
896
897<p>The return type and each parameter of a function type may have a set of
898 <i>parameter attributes</i> associated with them. Parameter attributes are
899 used to communicate additional information about the result or parameters of
900 a function. Parameter attributes are considered to be part of the function,
901 not of the function type, so functions with different parameter attributes
902 can have the same function type.</p>
903
904<p>Parameter attributes are simple keywords that follow the type specified. If
905 multiple parameter attributes are needed, they are space separated. For
906 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]907
908<div class="doc_code">
909<pre>
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]910declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]911declare i32 @atoi(i8 zeroext)
912declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]913</pre>
914</div>
915
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]916<p>Note that any attributes for the function result (<tt>nounwind</tt>,
917 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]918
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]919<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]920
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]921<dl>
922 <dt><tt>zeroext</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]923 <dd>This indicates to the code generator that the parameter or return value
924 should be zero-extended to a 32-bit value by the caller (for a parameter)
925 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]926
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]927 <dt><tt>signext</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]928 <dd>This indicates to the code generator that the parameter or return value
929 should be sign-extended to a 32-bit value by the caller (for a parameter)
930 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]931
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]932 <dt><tt>inreg</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]933 <dd>This indicates that this parameter or return value should be treated in a
934 special target-dependent fashion during while emitting code for a function
935 call or return (usually, by putting it in a register as opposed to memory,
936 though some targets use it to distinguish between two different kinds of
937 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]938
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]939 <dt><tt><a name="byval">byval</a></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]940 <dd>This indicates that the pointer parameter should really be passed by value
941 to the function. The attribute implies that a hidden copy of the pointee
942 is made between the caller and the callee, so the callee is unable to
943 modify the value in the callee. This attribute is only valid on LLVM
944 pointer arguments. It is generally used to pass structs and arrays by
945 value, but is also valid on pointers to scalars. The copy is considered
946 to belong to the caller not the callee (for example,
947 <tt><a href="#readonly">readonly</a></tt> functions should not write to
948 <tt>byval</tt> parameters). This is not a valid attribute for return
949 values. The byval attribute also supports specifying an alignment with
950 the align attribute. This has a target-specific effect on the code
951 generator that usually indicates a desired alignment for the synthesized
952 stack slot.</dd>
953
954 <dt><tt>sret</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]955 <dd>This indicates that the pointer parameter specifies the address of a
956 structure that is the return value of the function in the source program.
957 This pointer must be guaranteed by the caller to be valid: loads and
958 stores to the structure may be assumed by the callee to not to trap. This
959 may only be applied to the first parameter. This is not a valid attribute
960 for return values. </dd>
961
962 <dt><tt>noalias</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]963 <dd>This indicates that the pointer does not alias any global or any other
964 parameter. The caller is responsible for ensuring that this is the
965 case. On a function return value, <tt>noalias</tt> additionally indicates
966 that the pointer does not alias any other pointers visible to the
967 caller. For further details, please see the discussion of the NoAlias
968 response in
969 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
970 analysis</a>.</dd>
971
972 <dt><tt>nocapture</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]973 <dd>This indicates that the callee does not make any copies of the pointer
974 that outlive the callee itself. This is not a valid attribute for return
975 values.</dd>
976
977 <dt><tt>nest</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]978 <dd>This indicates that the pointer parameter can be excised using the
979 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
980 attribute for return values.</dd>
981</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]982
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]983</div>
984
985<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]986<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]987 <a name="gc">Garbage Collector Names</a>
988</div>
989
990<div class="doc_text">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]991
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]992<p>Each function may specify a garbage collector name, which is simply a
993 string:</p>
994
995<div class="doc_code">
996<pre>
997define void @f() gc "name" { ...
998</pre>
999</div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1000
1001<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1002 collector which will cause the compiler to alter its output in order to
1003 support the named garbage collection algorithm.</p>
1004
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1005</div>
1006
1007<!-- ======================================================================= -->
1008<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1009 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1010</div>
1011
1012<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1013
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1014<p>Function attributes are set to communicate additional information about a
1015 function. Function attributes are considered to be part of the function, not
1016 of the function type, so functions with different parameter attributes can
1017 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1018
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1019<p>Function attributes are simple keywords that follow the type specified. If
1020 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1021
1022<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1023<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1024define void @f() noinline { ... }
1025define void @f() alwaysinline { ... }
1026define void @f() alwaysinline optsize { ... }
1027define void @f() optsize
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1028</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1029</div>
1030
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1031<dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1032 <dt><tt>alwaysinline</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1033 <dd>This attribute indicates that the inliner should attempt to inline this
1034 function into callers whenever possible, ignoring any active inlining size
1035 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1036
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1037 <dt><tt>noinline</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1038 <dd>This attribute indicates that the inliner should never inline this
1039 function in any situation. This attribute may not be used together with
1040 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1041
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1042 <dt><tt>optsize</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1043 <dd>This attribute suggests that optimization passes and code generator passes
1044 make choices that keep the code size of this function low, and otherwise
1045 do optimizations specifically to reduce code size.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1046
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1047 <dt><tt>noreturn</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1048 <dd>This function attribute indicates that the function never returns
1049 normally. This produces undefined behavior at runtime if the function
1050 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1051
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1052 <dt><tt>nounwind</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1053 <dd>This function attribute indicates that the function never returns with an
1054 unwind or exceptional control flow. If the function does unwind, its
1055 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1056
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1057 <dt><tt>readnone</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1058 <dd>This attribute indicates that the function computes its result (or decides
1059 to unwind an exception) based strictly on its arguments, without
1060 dereferencing any pointer arguments or otherwise accessing any mutable
1061 state (e.g. memory, control registers, etc) visible to caller functions.
1062 It does not write through any pointer arguments
1063 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1064 changes any state visible to callers. This means that it cannot unwind
1065 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1066 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1067
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1068 <dt><tt><a name="readonly">readonly</a></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1069 <dd>This attribute indicates that the function does not write through any
1070 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1071 arguments) or otherwise modify any state (e.g. memory, control registers,
1072 etc) visible to caller functions. It may dereference pointer arguments
1073 and read state that may be set in the caller. A readonly function always
1074 returns the same value (or unwinds an exception identically) when called
1075 with the same set of arguments and global state. It cannot unwind an
1076 exception by calling the <tt>C++</tt> exception throwing methods, but may
1077 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1078
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1079 <dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1080 <dd>This attribute indicates that the function should emit a stack smashing
1081 protector. It is in the form of a "canary"&mdash;a random value placed on
1082 the stack before the local variables that's checked upon return from the
1083 function to see if it has been overwritten. A heuristic is used to
1084 determine if a function needs stack protectors or not.<br>
1085<br>
1086 If a function that has an <tt>ssp</tt> attribute is inlined into a
1087 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1088 function will have an <tt>ssp</tt> attribute.</dd>
1089
1090 <dt><tt>sspreq</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1091 <dd>This attribute indicates that the function should <em>always</em> emit a
1092 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1093 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1094<br>
1095 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1096 function that doesn't have an <tt>sspreq</tt> attribute or which has
1097 an <tt>ssp</tt> attribute, then the resulting function will have
1098 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1099
1100 <dt><tt>noredzone</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1101 <dd>This attribute indicates that the code generator should not use a red
1102 zone, even if the target-specific ABI normally permits it.</dd>
1103
1104 <dt><tt>noimplicitfloat</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1105 <dd>This attributes disables implicit floating point instructions.</dd>
1106
1107 <dt><tt>naked</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1108 <dd>This attribute disables prologue / epilogue emission for the function.
1109 This can have very system-specific consequences.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1110</dl>
1111
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1112</div>
1113
1114<!-- ======================================================================= -->
1115<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1116 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1117</div>
1118
1119<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1120
1121<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1122 the GCC "file scope inline asm" blocks. These blocks are internally
1123 concatenated by LLVM and treated as a single unit, but may be separated in
1124 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1125
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1126<div class="doc_code">
1127<pre>
1128module asm "inline asm code goes here"
1129module asm "more can go here"
1130</pre>
1131</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1132
1133<p>The strings can contain any character by escaping non-printable characters.
1134 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1135 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1136
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1137<p>The inline asm code is simply printed to the machine code .s file when
1138 assembly code is generated.</p>
1139
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1140</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1141
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1142<!-- ======================================================================= -->
1143<div class="doc_subsection">
1144 <a name="datalayout">Data Layout</a>
1145</div>
1146
1147<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1148
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1149<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1150 data is to be laid out in memory. The syntax for the data layout is
1151 simply:</p>
1152
1153<div class="doc_code">
1154<pre>
1155target datalayout = "<i>layout specification</i>"
1156</pre>
1157</div>
1158
1159<p>The <i>layout specification</i> consists of a list of specifications
1160 separated by the minus sign character ('-'). Each specification starts with
1161 a letter and may include other information after the letter to define some
1162 aspect of the data layout. The specifications accepted are as follows:</p>
1163
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1164<dl>
1165 <dt><tt>E</tt></dt>
1166 <dd>Specifies that the target lays out data in big-endian form. That is, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1167 bits with the most significance have the lowest address location.</dd>
1168
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1169 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1170 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1171 the bits with the least significance have the lowest address
1172 location.</dd>
1173
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1174 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1175 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1176 <i>preferred</i> alignments. All sizes are in bits. Specifying
1177 the <i>pref</i> alignment is optional. If omitted, the
1178 preceding <tt>:</tt> should be omitted too.</dd>
1179
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1180 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1181 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1182 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1183
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1184 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1185 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1186 <i>size</i>.</dd>
1187
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1188 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1189 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1190 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1191 (double).</dd>
1192
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1193 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1194 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1195 <i>size</i>.</dd>
1196
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1197 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1198 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1199 <i>size</i>.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1200</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1201
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1202<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1203 default set of specifications which are then (possibly) overriden by the
1204 specifications in the <tt>datalayout</tt> keyword. The default specifications
1205 are given in this list:</p>
1206
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1207<ul>
1208 <li><tt>E</tt> - big endian</li>
1209 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1210 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1211 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1212 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1213 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1214 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1215 alignment of 64-bits</li>
1216 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1217 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1218 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1219 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1220 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1221 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1222</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1223
1224<p>When LLVM is determining the alignment for a given type, it uses the
1225 following rules:</p>
1226
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1227<ol>
1228 <li>If the type sought is an exact match for one of the specifications, that
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1229 specification is used.</li>
1230
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1231 <li>If no match is found, and the type sought is an integer type, then the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1232 smallest integer type that is larger than the bitwidth of the sought type
1233 is used. If none of the specifications are larger than the bitwidth then
1234 the the largest integer type is used. For example, given the default
1235 specifications above, the i7 type will use the alignment of i8 (next
1236 largest) while both i65 and i256 will use the alignment of i64 (largest
1237 specified).</li>
1238
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1239 <li>If no match is found, and the type sought is a vector type, then the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1240 largest vector type that is smaller than the sought vector type will be
1241 used as a fall back. This happens because &lt;128 x double&gt; can be
1242 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1243</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1244
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1245</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1246
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1247<!-- ======================================================================= -->
1248<div class="doc_subsection">
1249 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1250</div>
1251
1252<div class="doc_text">
1253
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1254<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1255with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1256is undefined. Pointer values are associated with address ranges
1257according to the following rules:</p>
1258
1259<ul>
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1260 <li>A pointer value formed from a
1261 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1262 is associated with the addresses associated with the first operand
1263 of the <tt>getelementptr</tt>.</li>
1264 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1265 range of the variable's storage.</li>
1266 <li>The result value of an allocation instruction is associated with
1267 the address range of the allocated storage.</li>
1268 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1269 no address.</li>
1270 <li>A pointer value formed by an
1271 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1272 address ranges of all pointer values that contribute (directly or
1273 indirectly) to the computation of the pointer's value.</li>
1274 <li>The result value of a
1275 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1276 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1277 <li>An integer constant other than zero or a pointer value returned
1278 from a function not defined within LLVM may be associated with address
1279 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1280 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1281 allocated by mechanisms provided by LLVM.</li>
1282 </ul>
1283
1284<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1285<tt><a href="#i_load">load</a></tt> merely indicates the size and
1286alignment of the memory from which to load, as well as the
1287interpretation of the value. The first operand of a
1288<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1289and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1290
1291<p>Consequently, type-based alias analysis, aka TBAA, aka
1292<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1293LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1294additional information which specialized optimization passes may use
1295to implement type-based alias analysis.</p>
1296
1297</div>
1298
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1299<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1300<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1301<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1302
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1303<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1304
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1305<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1306 intermediate representation. Being typed enables a number of optimizations
1307 to be performed on the intermediate representation directly, without having
1308 to do extra analyses on the side before the transformation. A strong type
1309 system makes it easier to read the generated code and enables novel analyses
1310 and transformations that are not feasible to perform on normal three address
1311 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1312
1313</div>
1314
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1315<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1316<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1317Classifications</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1318
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1319<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1320
1321<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1322
1323<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1324 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1325 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1326 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1327 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1328 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1329 </tr>
1330 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1331 <td><a href="#t_floating">floating point</a></td>
1332 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1333 </tr>
1334 <tr>
1335 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1336 <td><a href="#t_integer">integer</a>,
1337 <a href="#t_floating">floating point</a>,
1338 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1339 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1340 <a href="#t_struct">structure</a>,
1341 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1342 <a href="#t_label">label</a>,
1343 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1344 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1345 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1346 <tr>
1347 <td><a href="#t_primitive">primitive</a></td>
1348 <td><a href="#t_label">label</a>,
1349 <a href="#t_void">void</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1350 <a href="#t_floating">floating point</a>,
1351 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1352 </tr>
1353 <tr>
1354 <td><a href="#t_derived">derived</a></td>
1355 <td><a href="#t_integer">integer</a>,
1356 <a href="#t_array">array</a>,
1357 <a href="#t_function">function</a>,
1358 <a href="#t_pointer">pointer</a>,
1359 <a href="#t_struct">structure</a>,
1360 <a href="#t_pstruct">packed structure</a>,
1361 <a href="#t_vector">vector</a>,
1362 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1363 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1364 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1365 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1366</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1367
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1368<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1369 important. Values of these types are the only ones which can be produced by
1370 instructions, passed as arguments, or used as operands to instructions.</p>
1371
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1372</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1373
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1374<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1375<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1376
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1377<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1378
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1379<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1380 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1381
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1382</div>
1383
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1384<!-- _______________________________________________________________________ -->
1385<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1386
1387<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1388
1389<table>
1390 <tbody>
1391 <tr><th>Type</th><th>Description</th></tr>
1392 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1393 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1394 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1395 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1396 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1397 </tbody>
1398</table>
1399
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1400</div>
1401
1402<!-- _______________________________________________________________________ -->
1403<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1404
1405<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1406
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1407<h5>Overview:</h5>
1408<p>The void type does not represent any value and has no size.</p>
1409
1410<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1411<pre>
1412 void
1413</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1414
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1415</div>
1416
1417<!-- _______________________________________________________________________ -->
1418<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1419
1420<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1421
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1422<h5>Overview:</h5>
1423<p>The label type represents code labels.</p>
1424
1425<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1426<pre>
1427 label
1428</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1429
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1430</div>
1431
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1432<!-- _______________________________________________________________________ -->
1433<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1434
1435<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1436
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1437<h5>Overview:</h5>
1438<p>The metadata type represents embedded metadata. The only derived type that
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1439 may contain metadata is <tt>metadata*</tt> or a function type that returns or
1440 takes metadata typed parameters, but not pointer to metadata types.</p>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1441
1442<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1443<pre>
1444 metadata
1445</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1446
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1447</div>
1448
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1449
1450<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1451<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1452
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1453<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1454
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1455<p>The real power in LLVM comes from the derived types in the system. This is
1456 what allows a programmer to represent arrays, functions, pointers, and other
1457 useful types. Note that these derived types may be recursive: For example,
1458 it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1459
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1460</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1461
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1462<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1463<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1464
1465<div class="doc_text">
1466
1467<h5>Overview:</h5>
1468<p>The integer type is a very simple derived type that simply specifies an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1469 arbitrary bit width for the integer type desired. Any bit width from 1 bit to
1470 2^23-1 (about 8 million) can be specified.</p>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1471
1472<h5>Syntax:</h5>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1473<pre>
1474 iN
1475</pre>
1476
1477<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1478 value.</p>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1479
1480<h5>Examples:</h5>
1481<table class="layout">
Nick Lewyckyaab930a2009-05-24 02:46:06 +0000[diff] [blame]1482 <tr class="layout">
1483 <td class="left"><tt>i1</tt></td>
1484 <td class="left">a single-bit integer.</td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1485 </tr>
Nick Lewyckyaab930a2009-05-24 02:46:06 +0000[diff] [blame]1486 <tr class="layout">
1487 <td class="left"><tt>i32</tt></td>
1488 <td class="left">a 32-bit integer.</td>
1489 </tr>
1490 <tr class="layout">
1491 <td class="left"><tt>i1942652</tt></td>
1492 <td class="left">a really big integer of over 1 million bits.</td>
1493 </tr>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1494</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1495
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1496<p>Note that the code generator does not yet support large integer types to be
1497 used as function return types. The specific limit on how large a return type
1498 the code generator can currently handle is target-dependent; currently it's
1499 often 64 bits for 32-bit targets and 128 bits for 64-bit targets.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1500
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1501</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1502
1503<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1504<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1505
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1506<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1507
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1508<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1509<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1510 sequentially in memory. The array type requires a size (number of elements)
1511 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1512
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1513<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1514<pre>
1515 [&lt;# elements&gt; x &lt;elementtype&gt;]
1516</pre>
1517
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1518<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1519 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1520
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1521<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1522<table class="layout">
1523 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1524 <td class="left"><tt>[40 x i32]</tt></td>
1525 <td class="left">Array of 40 32-bit integer values.</td>
1526 </tr>
1527 <tr class="layout">
1528 <td class="left"><tt>[41 x i32]</tt></td>
1529 <td class="left">Array of 41 32-bit integer values.</td>
1530 </tr>
1531 <tr class="layout">
1532 <td class="left"><tt>[4 x i8]</tt></td>
1533 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1534 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1535</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1536<p>Here are some examples of multidimensional arrays:</p>
1537<table class="layout">
1538 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1539 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1540 <td class="left">3x4 array of 32-bit integer values.</td>
1541 </tr>
1542 <tr class="layout">
1543 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1544 <td class="left">12x10 array of single precision floating point values.</td>
1545 </tr>
1546 <tr class="layout">
1547 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1548 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1549 </tr>
1550</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1551
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1552<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1553 length array. Normally, accesses past the end of an array are undefined in
1554 LLVM (e.g. it is illegal to access the 5th element of a 3 element array). As
1555 a special case, however, zero length arrays are recognized to be variable
1556 length. This allows implementation of 'pascal style arrays' with the LLVM
1557 type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1558
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1559<p>Note that the code generator does not yet support large aggregate types to be
1560 used as function return types. The specific limit on how large an aggregate
1561 return type the code generator can currently handle is target-dependent, and
1562 also dependent on the aggregate element types.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1563
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1564</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1565
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1566<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1567<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1568
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1569<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1570
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1571<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1572<p>The function type can be thought of as a function signature. It consists of
1573 a return type and a list of formal parameter types. The return type of a
1574 function type is a scalar type, a void type, or a struct type. If the return
1575 type is a struct type then all struct elements must be of first class types,
1576 and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1577
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1578<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1579<pre>
1580 &lt;returntype list&gt; (&lt;parameter list&gt;)
1581</pre>
1582
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1583<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1584 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1585 which indicates that the function takes a variable number of arguments.
1586 Variable argument functions can access their arguments with
1587 the <a href="#int_varargs">variable argument handling intrinsic</a>
1588 functions. '<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1589 <a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1590
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1591<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1592<table class="layout">
1593 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1594 <td class="left"><tt>i32 (i32)</tt></td>
1595 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1596 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1597 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1598 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1599 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1600 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1601 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1602 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1603 <tt>float</tt>.
1604 </td>
1605 </tr><tr class="layout">
1606 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1607 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1608 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1609 which returns an integer. This is the signature for <tt>printf</tt> in
1610 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1611 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1612 </tr><tr class="layout">
1613 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanc9813bd2008-11-27 06:41:20 +0000[diff] [blame]1614 <td class="left">A function taking an <tt>i32</tt>, returning two
1615 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1616 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1617 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1618</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1619
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1620</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1621
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1622<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1623<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1624
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1625<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1626
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1627<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1628<p>The structure type is used to represent a collection of data members together
1629 in memory. The packing of the field types is defined to match the ABI of the
1630 underlying processor. The elements of a structure may be any type that has a
1631 size.</p>
1632
1633<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1634 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1635 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1636
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1637<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1638<pre>
1639 { &lt;type list&gt; }
1640</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1641
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1642<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1643<table class="layout">
1644 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1645 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1646 <td class="left">A triple of three <tt>i32</tt> values</td>
1647 </tr><tr class="layout">
1648 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1649 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1650 second element is a <a href="#t_pointer">pointer</a> to a
1651 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1652 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1653 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1654</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1655
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1656<p>Note that the code generator does not yet support large aggregate types to be
1657 used as function return types. The specific limit on how large an aggregate
1658 return type the code generator can currently handle is target-dependent, and
1659 also dependent on the aggregate element types.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1660
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1661</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1662
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1663<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1664<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1665</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1666
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1667<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1668
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1669<h5>Overview:</h5>
1670<p>The packed structure type is used to represent a collection of data members
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1671 together in memory. There is no padding between fields. Further, the
1672 alignment of a packed structure is 1 byte. The elements of a packed
1673 structure may be any type that has a size.</p>
1674
1675<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1676 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1677 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1678
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1679<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1680<pre>
1681 &lt; { &lt;type list&gt; } &gt;
1682</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1683
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1684<h5>Examples:</h5>
1685<table class="layout">
1686 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1687 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1688 <td class="left">A triple of three <tt>i32</tt> values</td>
1689 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1690 <td class="left">
1691<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1692 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1693 second element is a <a href="#t_pointer">pointer</a> to a
1694 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1695 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1696 </tr>
1697</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1698
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1699</div>
1700
1701<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1702<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1703
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1704<div class="doc_text">
1705
1706<h5>Overview:</h5>
1707<p>As in many languages, the pointer type represents a pointer or reference to
1708 another object, which must live in memory. Pointer types may have an optional
1709 address space attribute defining the target-specific numbered address space
1710 where the pointed-to object resides. The default address space is zero.</p>
1711
1712<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1713 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1714
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1715<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1716<pre>
1717 &lt;type&gt; *
1718</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1719
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1720<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1721<table class="layout">
1722 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1723 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1724 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1725 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1726 </tr>
1727 <tr class="layout">
1728 <td class="left"><tt>i32 (i32 *) *</tt></td>
1729 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1730 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1731 <tt>i32</tt>.</td>
1732 </tr>
1733 <tr class="layout">
1734 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1735 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1736 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1737 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1738</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1739
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1740</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1741
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1742<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1743<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1744
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1745<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1746
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1747<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1748<p>A vector type is a simple derived type that represents a vector of elements.
1749 Vector types are used when multiple primitive data are operated in parallel
1750 using a single instruction (SIMD). A vector type requires a size (number of
1751 elements) and an underlying primitive data type. Vectors must have a power
1752 of two length (1, 2, 4, 8, 16 ...). Vector types are considered
1753 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1754
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1755<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1756<pre>
1757 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1758</pre>
1759
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1760<p>The number of elements is a constant integer value; elementtype may be any
1761 integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1762
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1763<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1764<table class="layout">
1765 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1766 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1767 <td class="left">Vector of 4 32-bit integer values.</td>
1768 </tr>
1769 <tr class="layout">
1770 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1771 <td class="left">Vector of 8 32-bit floating-point values.</td>
1772 </tr>
1773 <tr class="layout">
1774 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1775 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1776 </tr>
1777</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1778
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1779<p>Note that the code generator does not yet support large vector types to be
1780 used as function return types. The specific limit on how large a vector
1781 return type codegen can currently handle is target-dependent; currently it's
1782 often a few times longer than a hardware vector register.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1783
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1784</div>
1785
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1786<!-- _______________________________________________________________________ -->
1787<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1788<div class="doc_text">
1789
1790<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1791<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1792 corresponds (for example) to the C notion of a forward declared structure
1793 type. In LLVM, opaque types can eventually be resolved to any type (not just
1794 a structure type).</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1795
1796<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1797<pre>
1798 opaque
1799</pre>
1800
1801<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1802<table class="layout">
1803 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1804 <td class="left"><tt>opaque</tt></td>
1805 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1806 </tr>
1807</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1808
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1809</div>
1810
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1811<!-- ======================================================================= -->
1812<div class="doc_subsection">
1813 <a name="t_uprefs">Type Up-references</a>
1814</div>
1815
1816<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1817
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1818<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1819<p>An "up reference" allows you to refer to a lexically enclosing type without
1820 requiring it to have a name. For instance, a structure declaration may
1821 contain a pointer to any of the types it is lexically a member of. Example
1822 of up references (with their equivalent as named type declarations)
1823 include:</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1824
1825<pre>
Chris Lattnerbf1d5452009-02-09 10:00:56 +0000[diff] [blame]1826 { \2 * } %x = type { %x* }
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1827 { \2 }* %y = type { %y }*
1828 \1* %z = type %z*
1829</pre>
1830
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1831<p>An up reference is needed by the asmprinter for printing out cyclic types
1832 when there is no declared name for a type in the cycle. Because the
1833 asmprinter does not want to print out an infinite type string, it needs a
1834 syntax to handle recursive types that have no names (all names are optional
1835 in llvm IR).</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1836
1837<h5>Syntax:</h5>
1838<pre>
1839 \&lt;level&gt;
1840</pre>
1841
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1842<p>The level is the count of the lexical type that is being referred to.</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1843
1844<h5>Examples:</h5>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1845<table class="layout">
1846 <tr class="layout">
1847 <td class="left"><tt>\1*</tt></td>
1848 <td class="left">Self-referential pointer.</td>
1849 </tr>
1850 <tr class="layout">
1851 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1852 <td class="left">Recursive structure where the upref refers to the out-most
1853 structure.</td>
1854 </tr>
1855</table>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1856
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1857</div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1858
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1859<!-- *********************************************************************** -->
1860<div class="doc_section"> <a name="constants">Constants</a> </div>
1861<!-- *********************************************************************** -->
1862
1863<div class="doc_text">
1864
1865<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1866 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1867
1868</div>
1869
1870<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1871<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1872
1873<div class="doc_text">
1874
1875<dl>
1876 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1877 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1878 constants of the <tt><a href="#t_primitive">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1879
1880 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1881 <dd>Standard integers (such as '4') are constants of
1882 the <a href="#t_integer">integer</a> type. Negative numbers may be used
1883 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1884
1885 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1886 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1887 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
1888 notation (see below). The assembler requires the exact decimal value of a
1889 floating-point constant. For example, the assembler accepts 1.25 but
1890 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1891 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1892
1893 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1894 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1895 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1896</dl>
1897
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1898<p>The one non-intuitive notation for constants is the hexadecimal form of
1899 floating point constants. For example, the form '<tt>double
1900 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
1901 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
1902 constants are required (and the only time that they are generated by the
1903 disassembler) is when a floating point constant must be emitted but it cannot
1904 be represented as a decimal floating point number in a reasonable number of
1905 digits. For example, NaN's, infinities, and other special values are
1906 represented in their IEEE hexadecimal format so that assembly and disassembly
1907 do not cause any bits to change in the constants.</p>
1908
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]1909<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1910 represented using the 16-digit form shown above (which matches the IEEE754
1911 representation for double); float values must, however, be exactly
1912 representable as IEE754 single precision. Hexadecimal format is always used
1913 for long double, and there are three forms of long double. The 80-bit format
1914 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
1915 The 128-bit format used by PowerPC (two adjacent doubles) is represented
1916 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
1917 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
1918 currently supported target uses this format. Long doubles will only work if
1919 they match the long double format on your target. All hexadecimal formats
1920 are big-endian (sign bit at the left).</p>
1921
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1922</div>
1923
1924<!-- ======================================================================= -->
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]1925<div class="doc_subsection">
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]1926<a name="aggregateconstants"></a> <!-- old anchor -->
1927<a name="complexconstants">Complex Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1928</div>
1929
1930<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1931
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]1932<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1933 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1934
1935<dl>
1936 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1937 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1938 type definitions (a comma separated list of elements, surrounded by braces
1939 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1940 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
1941 Structure constants must have <a href="#t_struct">structure type</a>, and
1942 the number and types of elements must match those specified by the
1943 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1944
1945 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1946 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1947 definitions (a comma separated list of elements, surrounded by square
1948 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
1949 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
1950 the number and types of elements must match those specified by the
1951 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1952
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1953 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1954 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1955 definitions (a comma separated list of elements, surrounded by
1956 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
1957 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
1958 have <a href="#t_vector">vector type</a>, and the number and types of
1959 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1960
1961 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1962 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1963 value to zero of <em>any</em> type, including scalar and aggregate types.
1964 This is often used to avoid having to print large zero initializers
1965 (e.g. for large arrays) and is always exactly equivalent to using explicit
1966 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]1967
1968 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]1969 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1970 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
1971 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
1972 be interpreted as part of the instruction stream, metadata is a place to
1973 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1974</dl>
1975
1976</div>
1977
1978<!-- ======================================================================= -->
1979<div class="doc_subsection">
1980 <a name="globalconstants">Global Variable and Function Addresses</a>
1981</div>
1982
1983<div class="doc_text">
1984
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1985<p>The addresses of <a href="#globalvars">global variables</a>
1986 and <a href="#functionstructure">functions</a> are always implicitly valid
1987 (link-time) constants. These constants are explicitly referenced when
1988 the <a href="#identifiers">identifier for the global</a> is used and always
1989 have <a href="#t_pointer">pointer</a> type. For example, the following is a
1990 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1991
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1992<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1993<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]1994@X = global i32 17
1995@Y = global i32 42
1996@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1997</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1998</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1999
2000</div>
2001
2002<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]2003<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2004<div class="doc_text">
2005
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2006<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has no
2007 specific value. Undefined values may be of any type and be used anywhere a
2008 constant is permitted.</p>
2009
2010<p>Undefined values indicate to the compiler that the program is well defined no
2011 matter what value is used, giving the compiler more freedom to optimize.</p>
2012
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2013</div>
2014
2015<!-- ======================================================================= -->
2016<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2017</div>
2018
2019<div class="doc_text">
2020
2021<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2022 to be used as constants. Constant expressions may be of
2023 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2024 operation that does not have side effects (e.g. load and call are not
2025 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2026
2027<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2028 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2029 <dd>Truncate a constant to another type. The bit size of CST must be larger
2030 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2031
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2032 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2033 <dd>Zero extend a constant to another type. The bit size of CST must be
2034 smaller or equal to the bit size of TYPE. Both types must be
2035 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2036
2037 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2038 <dd>Sign extend a constant to another type. The bit size of CST must be
2039 smaller or equal to the bit size of TYPE. Both types must be
2040 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2041
2042 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2043 <dd>Truncate a floating point constant to another floating point type. The
2044 size of CST must be larger than the size of TYPE. Both types must be
2045 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2046
2047 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2048 <dd>Floating point extend a constant to another type. The size of CST must be
2049 smaller or equal to the size of TYPE. Both types must be floating
2050 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2051
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]2052 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2053 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2054 constant. TYPE must be a scalar or vector integer type. CST must be of
2055 scalar or vector floating point type. Both CST and TYPE must be scalars,
2056 or vectors of the same number of elements. If the value won't fit in the
2057 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2058
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2059 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2060 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2061 constant. TYPE must be a scalar or vector integer type. CST must be of
2062 scalar or vector floating point type. Both CST and TYPE must be scalars,
2063 or vectors of the same number of elements. If the value won't fit in the
2064 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2065
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2066 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2067 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2068 constant. TYPE must be a scalar or vector floating point type. CST must be
2069 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2070 vectors of the same number of elements. If the value won't fit in the
2071 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2072
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2073 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2074 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2075 constant. TYPE must be a scalar or vector floating point type. CST must be
2076 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2077 vectors of the same number of elements. If the value won't fit in the
2078 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2079
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2080 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2081 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2082 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2083 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2084 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2085
2086 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2087 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2088 type. CST must be of integer type. The CST value is zero extended,
2089 truncated, or unchanged to make it fit in a pointer size. This one is
2090 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2091
2092 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2093 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2094 are the same as those for the <a href="#i_bitcast">bitcast
2095 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2096
2097 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]2098 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2099 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2100 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2101 instruction, the index list may have zero or more indexes, which are
2102 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2103
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2104 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2105 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2106
2107 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2108 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2109
2110 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2111 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2112
2113 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2114 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2115 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2116
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]2117 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2118 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2119 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2120
2121 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2122 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2123 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2124
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2125 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2126 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2127 be any of the <a href="#binaryops">binary</a>
2128 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2129 on operands are the same as those for the corresponding instruction
2130 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2131</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2132
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2133</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2134
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2135<!-- ======================================================================= -->
2136<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
2137</div>
2138
2139<div class="doc_text">
2140
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2141<p>Embedded metadata provides a way to attach arbitrary data to the instruction
2142 stream without affecting the behaviour of the program. There are two
2143 metadata primitives, strings and nodes. All metadata has the
2144 <tt>metadata</tt> type and is identified in syntax by a preceding exclamation
2145 point ('<tt>!</tt>').</p>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2146
2147<p>A metadata string is a string surrounded by double quotes. It can contain
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2148 any character by escaping non-printable characters with "\xx" where "xx" is
2149 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2150
2151<p>Metadata nodes are represented with notation similar to structure constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2152 (a comma separated list of elements, surrounded by braces and preceeded by an
2153 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2154 10}</tt>".</p>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2155
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2156<p>A metadata node will attempt to track changes to the values it holds. In the
2157 event that a value is deleted, it will be replaced with a typeless
2158 "<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewyckyb8f9b7a2009-05-10 20:57:05 +0000[diff] [blame]2159
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2160<p>Optimizations may rely on metadata to provide additional information about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2161 the program that isn't available in the instructions, or that isn't easily
2162 computable. Similarly, the code generator may expect a certain metadata
2163 format to be used to express debugging information.</p>
2164
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2165</div>
2166
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2167<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2168<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2169<!-- *********************************************************************** -->
2170
2171<!-- ======================================================================= -->
2172<div class="doc_subsection">
2173<a name="inlineasm">Inline Assembler Expressions</a>
2174</div>
2175
2176<div class="doc_text">
2177
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2178<p>LLVM supports inline assembler expressions (as opposed
2179 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2180 a special value. This value represents the inline assembler as a string
2181 (containing the instructions to emit), a list of operand constraints (stored
2182 as a string), and a flag that indicates whether or not the inline asm
2183 expression has side effects. An example inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2184
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2185<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2186<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2187i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2188</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2189</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2190
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2191<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2192 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2193 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2194
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2195<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2196<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2197%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2198</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2199</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2200
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2201<p>Inline asms with side effects not visible in the constraint list must be
2202 marked as having side effects. This is done through the use of the
2203 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2204
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2205<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2206<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2207call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2208</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2209</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2210
2211<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2212 documented here. Constraints on what can be done (e.g. duplication, moving,
2213 etc need to be documented). This is probably best done by reference to
2214 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2215
2216</div>
2217
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2218
2219<!-- *********************************************************************** -->
2220<div class="doc_section">
2221 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2222</div>
2223<!-- *********************************************************************** -->
2224
2225<p>LLVM has a number of "magic" global variables that contain data that affect
2226code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2227of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2228section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2229by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2230
2231<!-- ======================================================================= -->
2232<div class="doc_subsection">
2233<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2234</div>
2235
2236<div class="doc_text">
2237
2238<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2239href="#linkage_appending">appending linkage</a>. This array contains a list of
2240pointers to global variables and functions which may optionally have a pointer
2241cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2242
2243<pre>
2244 @X = global i8 4
2245 @Y = global i32 123
2246
2247 @llvm.used = appending global [2 x i8*] [
2248 i8* @X,
2249 i8* bitcast (i32* @Y to i8*)
2250 ], section "llvm.metadata"
2251</pre>
2252
2253<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2254compiler, assembler, and linker are required to treat the symbol as if there is
2255a reference to the global that it cannot see. For example, if a variable has
2256internal linkage and no references other than that from the <tt>@llvm.used</tt>
2257list, it cannot be deleted. This is commonly used to represent references from
2258inline asms and other things the compiler cannot "see", and corresponds to
2259"attribute((used))" in GNU C.</p>
2260
2261<p>On some targets, the code generator must emit a directive to the assembler or
2262object file to prevent the assembler and linker from molesting the symbol.</p>
2263
2264</div>
2265
2266<!-- ======================================================================= -->
2267<div class="doc_subsection">
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2268<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2269</div>
2270
2271<div class="doc_text">
2272
2273<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2274<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2275touching the symbol. On targets that support it, this allows an intelligent
2276linker to optimize references to the symbol without being impeded as it would be
2277by <tt>@llvm.used</tt>.</p>
2278
2279<p>This is a rare construct that should only be used in rare circumstances, and
2280should not be exposed to source languages.</p>
2281
2282</div>
2283
2284<!-- ======================================================================= -->
2285<div class="doc_subsection">
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2286<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2287</div>
2288
2289<div class="doc_text">
2290
2291<p>TODO: Describe this.</p>
2292
2293</div>
2294
2295<!-- ======================================================================= -->
2296<div class="doc_subsection">
2297<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2298</div>
2299
2300<div class="doc_text">
2301
2302<p>TODO: Describe this.</p>
2303
2304</div>
2305
2306
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2307<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2308<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2309<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2310
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2311<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2312
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2313<p>The LLVM instruction set consists of several different classifications of
2314 instructions: <a href="#terminators">terminator
2315 instructions</a>, <a href="#binaryops">binary instructions</a>,
2316 <a href="#bitwiseops">bitwise binary instructions</a>,
2317 <a href="#memoryops">memory instructions</a>, and
2318 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2319
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2320</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2321
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2322<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2323<div class="doc_subsection"> <a name="terminators">Terminator
2324Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2325
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2326<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2327
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2328<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2329 in a program ends with a "Terminator" instruction, which indicates which
2330 block should be executed after the current block is finished. These
2331 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2332 control flow, not values (the one exception being the
2333 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2334
2335<p>There are six different terminator instructions: the
2336 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2337 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2338 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
2339 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2340 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2341 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2342
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2343</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2344
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2345<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2346<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2347Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2348
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2349<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2350
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2351<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2352<pre>
2353 ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2354 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2355</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2356
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2357<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2358<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2359 a value) from a function back to the caller.</p>
2360
2361<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2362 value and then causes control flow, and one that just causes control flow to
2363 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2364
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2365<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2366<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2367 return value. The type of the return value must be a
2368 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2369
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2370<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2371 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2372 value or a return value with a type that does not match its type, or if it
2373 has a void return type and contains a '<tt>ret</tt>' instruction with a
2374 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2375
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2376<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2377<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2378 the calling function's context. If the caller is a
2379 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2380 instruction after the call. If the caller was an
2381 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2382 the beginning of the "normal" destination block. If the instruction returns
2383 a value, that value shall set the call or invoke instruction's return
2384 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2385
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2386<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2387<pre>
2388 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2389 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]2390 ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2391</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2392
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2393<p>Note that the code generator does not yet fully support large
2394 return values. The specific sizes that are currently supported are
2395 dependent on the target. For integers, on 32-bit targets the limit
2396 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2397 For aggregate types, the current limits are dependent on the element
2398 types; for example targets are often limited to 2 total integer
2399 elements and 2 total floating-point elements.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2400
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2401</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2402<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2403<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2404
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2405<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2406
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2407<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2408<pre>
2409 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2410</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2411
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2412<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2413<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2414 different basic block in the current function. There are two forms of this
2415 instruction, corresponding to a conditional branch and an unconditional
2416 branch.</p>
2417
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2418<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2419<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2420 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2421 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2422 target.</p>
2423
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2424<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2425<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2426 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2427 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2428 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2429
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2430<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2431<pre>
2432Test:
2433 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2434 br i1 %cond, label %IfEqual, label %IfUnequal
2435IfEqual:
2436 <a href="#i_ret">ret</a> i32 1
2437IfUnequal:
2438 <a href="#i_ret">ret</a> i32 0
2439</pre>
2440
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2441</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2442
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2443<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2444<div class="doc_subsubsection">
2445 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2446</div>
2447
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2448<div class="doc_text">
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2449
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2450<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2451<pre>
2452 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2453</pre>
2454
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2455<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2456<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2457 several different places. It is a generalization of the '<tt>br</tt>'
2458 instruction, allowing a branch to occur to one of many possible
2459 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2460
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2461<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2462<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2463 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2464 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2465 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2466
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2467<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2468<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2469 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2470 is searched for the given value. If the value is found, control flow is
2471 transfered to the corresponding destination; otherwise, control flow is
2472 transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2473
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2474<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2475<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2476 <tt>switch</tt> instruction, this instruction may be code generated in
2477 different ways. For example, it could be generated as a series of chained
2478 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2479
2480<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2481<pre>
2482 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2483 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2484 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2485
2486 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2487 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2488
2489 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2490 switch i32 %val, label %otherwise [ i32 0, label %onzero
2491 i32 1, label %onone
2492 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2493</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2494
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2495</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2496
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2497<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2498<div class="doc_subsubsection">
2499 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2500</div>
2501
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2502<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2503
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2504<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2505<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2506 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner6b7a0082006-05-14 18:23:06 +0000[diff] [blame]2507 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2508</pre>
2509
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2510<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2511<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2512 function, with the possibility of control flow transfer to either the
2513 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2514 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2515 control flow will return to the "normal" label. If the callee (or any
2516 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2517 instruction, control is interrupted and continued at the dynamically nearest
2518 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2519
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2520<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2521<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2522
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2523<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2524 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2525 convention</a> the call should use. If none is specified, the call
2526 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2527
2528 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2529 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2530 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2531
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2532 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2533 function value being invoked. In most cases, this is a direct function
2534 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2535 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2536
2537 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2538 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2539
2540 <li>'<tt>function args</tt>': argument list whose types match the function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2541 signature argument types. If the function signature indicates the
2542 function accepts a variable number of arguments, the extra arguments can
2543 be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2544
2545 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2546 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2547
2548 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2549 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2550
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2551 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2552 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2553 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2554</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2555
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2556<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2557<p>This instruction is designed to operate as a standard
2558 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2559 primary difference is that it establishes an association with a label, which
2560 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2561
2562<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2563 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2564 exception. Additionally, this is important for implementation of
2565 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2566
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2567<p>For the purposes of the SSA form, the definition of the value returned by the
2568 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2569 block to the "normal" label. If the callee unwinds then no return value is
2570 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]2571
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2572<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2573<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2574 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2575 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2576 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2577 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2578</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2579
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2580</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2581
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2582<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2583
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2584<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2585Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2586
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2587<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2588
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2589<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2590<pre>
2591 unwind
2592</pre>
2593
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2594<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2595<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2596 at the first callee in the dynamic call stack which used
2597 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
2598 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2599
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2600<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2601<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2602 immediately halt. The dynamic call stack is then searched for the
2603 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
2604 Once found, execution continues at the "exceptional" destination block
2605 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
2606 instruction in the dynamic call chain, undefined behavior results.</p>
2607
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2608</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2609
2610<!-- _______________________________________________________________________ -->
2611
2612<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2613Instruction</a> </div>
2614
2615<div class="doc_text">
2616
2617<h5>Syntax:</h5>
2618<pre>
2619 unreachable
2620</pre>
2621
2622<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2623<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2624 instruction is used to inform the optimizer that a particular portion of the
2625 code is not reachable. This can be used to indicate that the code after a
2626 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2627
2628<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2629<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2630
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2631</div>
2632
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2633<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2634<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2635
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2636<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2637
2638<p>Binary operators are used to do most of the computation in a program. They
2639 require two operands of the same type, execute an operation on them, and
2640 produce a single value. The operands might represent multiple data, as is
2641 the case with the <a href="#t_vector">vector</a> data type. The result value
2642 has the same type as its operands.</p>
2643
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2644<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2645
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2646</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2647
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2648<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2649<div class="doc_subsubsection">
2650 <a name="i_add">'<tt>add</tt>' Instruction</a>
2651</div>
2652
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2653<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2654
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2655<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2656<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2657 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2658 &lt;result&gt; = nuw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2659 &lt;result&gt; = nsw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2660 &lt;result&gt; = nuw nsw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2661</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2662
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2663<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2664<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2665
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2666<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2667<p>The two arguments to the '<tt>add</tt>' instruction must
2668 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2669 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2670
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2671<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2672<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2673
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2674<p>If the sum has unsigned overflow, the result returned is the mathematical
2675 result modulo 2<sup>n</sup>, where n is the bit width of the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2676
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2677<p>Because LLVM integers use a two's complement representation, this instruction
2678 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2679
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2680<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2681 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2682 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
2683 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2684
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2685<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2686<pre>
2687 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2688</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2689
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2690</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2691
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2692<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2693<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2694 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
2695</div>
2696
2697<div class="doc_text">
2698
2699<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2700<pre>
2701 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2702</pre>
2703
2704<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2705<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
2706
2707<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2708<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2709 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2710 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2711
2712<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2713<p>The value produced is the floating point sum of the two operands.</p>
2714
2715<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2716<pre>
2717 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
2718</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2719
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2720</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2721
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2722<!-- _______________________________________________________________________ -->
2723<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2724 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2725</div>
2726
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2727<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2728
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2729<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2730<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2731 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2732 &lt;result&gt; = nuw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2733 &lt;result&gt; = nsw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2734 &lt;result&gt; = nuw nsw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2735</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2736
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2737<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2738<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2739 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2740
2741<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2742 '<tt>neg</tt>' instruction present in most other intermediate
2743 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2744
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2745<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2746<p>The two arguments to the '<tt>sub</tt>' instruction must
2747 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2748 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2749
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2750<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2751<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2752
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2753<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2754 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
2755 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2756
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2757<p>Because LLVM integers use a two's complement representation, this instruction
2758 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2759
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2760<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2761 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2762 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
2763 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2764
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2765<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2766<pre>
2767 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2768 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2769</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2770
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2771</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2772
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2773<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2774<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2775 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
2776</div>
2777
2778<div class="doc_text">
2779
2780<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2781<pre>
2782 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2783</pre>
2784
2785<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2786<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2787 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2788
2789<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2790 '<tt>fneg</tt>' instruction present in most other intermediate
2791 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2792
2793<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2794<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2795 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2796 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2797
2798<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2799<p>The value produced is the floating point difference of the two operands.</p>
2800
2801<h5>Example:</h5>
2802<pre>
2803 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
2804 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
2805</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2806
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2807</div>
2808
2809<!-- _______________________________________________________________________ -->
2810<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2811 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2812</div>
2813
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2814<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2815
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2816<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2817<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2818 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2819 &lt;result&gt; = nuw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2820 &lt;result&gt; = nsw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2821 &lt;result&gt; = nuw nsw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2822</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2823
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2824<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2825<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2826
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2827<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2828<p>The two arguments to the '<tt>mul</tt>' instruction must
2829 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2830 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2831
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2832<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2833<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2834
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2835<p>If the result of the multiplication has unsigned overflow, the result
2836 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
2837 width of the result.</p>
2838
2839<p>Because LLVM integers use a two's complement representation, and the result
2840 is the same width as the operands, this instruction returns the correct
2841 result for both signed and unsigned integers. If a full product
2842 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
2843 be sign-extended or zero-extended as appropriate to the width of the full
2844 product.</p>
2845
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2846<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2847 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2848 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
2849 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2850
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2851<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2852<pre>
2853 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2854</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2855
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2856</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2857
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2858<!-- _______________________________________________________________________ -->
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2859<div class="doc_subsubsection">
2860 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
2861</div>
2862
2863<div class="doc_text">
2864
2865<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2866<pre>
2867 &lt;result&gt; = fmul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2868</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2869
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2870<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2871<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2872
2873<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2874<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2875 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2876 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2877
2878<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2879<p>The value produced is the floating point product of the two operands.</p>
2880
2881<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2882<pre>
2883 &lt;result&gt; = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2884</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2885
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2886</div>
2887
2888<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2889<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2890</a></div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2891
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2892<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2893
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2894<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2895<pre>
2896 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2897</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2898
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2899<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2900<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2901
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2902<h5>Arguments:</h5>
2903<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2904 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2905 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2906
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2907<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2908<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2909
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2910<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2911 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2912
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2913<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2914
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2915<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2916<pre>
2917 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2918</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2919
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2920</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2921
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2922<!-- _______________________________________________________________________ -->
2923<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2924</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2925
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2926<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2927
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2928<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2929<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2930 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2931 &lt;result&gt; = exact sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2932</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2933
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2934<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2935<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2936
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2937<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2938<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2939 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2940 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2941
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2942<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2943<p>The value produced is the signed integer quotient of the two operands rounded
2944 towards zero.</p>
2945
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2946<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2947 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2948
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2949<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2950 undefined behavior; this is a rare case, but can occur, for example, by doing
2951 a 32-bit division of -2147483648 by -1.</p>
2952
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]2953<p>If the <tt>exact</tt> keyword is present, the result value of the
2954 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
2955 would occur.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2956
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2957<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2958<pre>
2959 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2960</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2961
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2962</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2963
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2964<!-- _______________________________________________________________________ -->
2965<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2966Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2967
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2968<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2969
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2970<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2971<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2972 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2973</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2974
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2975<h5>Overview:</h5>
2976<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2977
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2978<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2979<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2980 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2981 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2982
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2983<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2984<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2985
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2986<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2987<pre>
2988 &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2989</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2990
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2991</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2992
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2993<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2994<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2995</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2996
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2997<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2998
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2999<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3000<pre>
3001 &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3002</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3003
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3004<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3005<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3006 division of its two arguments.</p>
3007
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3008<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3009<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3010 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3011 values. Both arguments must have identical types.</p>
3012
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3013<h5>Semantics:</h5>
3014<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3015 This instruction always performs an unsigned division to get the
3016 remainder.</p>
3017
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3018<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3019 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3020
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3021<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3022
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3023<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3024<pre>
3025 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3026</pre>
3027
3028</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3029
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3030<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3031<div class="doc_subsubsection">
3032 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3033</div>
3034
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3035<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3036
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3037<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3038<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3039 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3040</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3041
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3042<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3043<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3044 division of its two operands. This instruction can also take
3045 <a href="#t_vector">vector</a> versions of the values in which case the
3046 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3047
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3048<h5>Arguments:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3049<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3050 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3051 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3052
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3053<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3054<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3055 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3056 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3057 a value. For more information about the difference,
3058 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3059 Math Forum</a>. For a table of how this is implemented in various languages,
3060 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3061 Wikipedia: modulo operation</a>.</p>
3062
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3063<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3064 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3065
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3066<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3067 Overflow also leads to undefined behavior; this is a rare case, but can
3068 occur, for example, by taking the remainder of a 32-bit division of
3069 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3070 lets srem be implemented using instructions that return both the result of
3071 the division and the remainder.)</p>
3072
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3073<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3074<pre>
3075 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3076</pre>
3077
3078</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3079
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3080<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3081<div class="doc_subsubsection">
3082 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3083
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3084<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3085
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3086<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3087<pre>
3088 &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3089</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3090
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3091<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3092<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3093 its two operands.</p>
3094
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3095<h5>Arguments:</h5>
3096<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3097 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3098 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3099
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3100<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3101<p>This instruction returns the <i>remainder</i> of a division. The remainder
3102 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3103
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3104<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3105<pre>
3106 &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3107</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3108
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3109</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3110
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3111<!-- ======================================================================= -->
3112<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3113Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3114
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3115<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3116
3117<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3118 program. They are generally very efficient instructions and can commonly be
3119 strength reduced from other instructions. They require two operands of the
3120 same type, execute an operation on them, and produce a single value. The
3121 resulting value is the same type as its operands.</p>
3122
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3123</div>
3124
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3125<!-- _______________________________________________________________________ -->
3126<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3127Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3128
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3129<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3130
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3131<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3132<pre>
3133 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3134</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3135
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3136<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3137<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3138 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3139
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3140<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3141<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3142 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3143 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3144
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3145<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3146<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3147 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3148 is (statically or dynamically) negative or equal to or larger than the number
3149 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3150 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3151 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3152
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3153<h5>Example:</h5>
3154<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3155 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3156 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3157 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3158 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3159 &lt;result&gt; = shl &lt;2 x i32&gt; &lt; i32 1, i32 1&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 2, i32 4&gt;</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3160</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3161
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3162</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3163
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3164<!-- _______________________________________________________________________ -->
3165<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3166Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3167
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3168<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3169
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3170<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3171<pre>
3172 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3173</pre>
3174
3175<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3176<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3177 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3178
3179<h5>Arguments:</h5>
3180<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3181 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3182 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3183
3184<h5>Semantics:</h5>
3185<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3186 significant bits of the result will be filled with zero bits after the shift.
3187 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3188 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3189 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3190 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3191
3192<h5>Example:</h5>
3193<pre>
3194 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3195 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3196 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3197 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3198 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3199 &lt;result&gt; = lshr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0x7FFFFFFF, i32 1&gt;</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3200</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3201
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3202</div>
3203
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3204<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3205<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3206Instruction</a> </div>
3207<div class="doc_text">
3208
3209<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3210<pre>
3211 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3212</pre>
3213
3214<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3215<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3216 operand shifted to the right a specified number of bits with sign
3217 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3218
3219<h5>Arguments:</h5>
3220<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3221 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3222 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3223
3224<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3225<p>This instruction always performs an arithmetic shift right operation, The
3226 most significant bits of the result will be filled with the sign bit
3227 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3228 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3229 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3230 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3231
3232<h5>Example:</h5>
3233<pre>
3234 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3235 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3236 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3237 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3238 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3239 &lt;result&gt; = ashr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 3&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 -1, i32 0&gt;</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3240</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3241
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3242</div>
3243
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3244<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3245<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3246Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3247
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3248<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3249
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3250<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3251<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3252 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3253</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3254
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3255<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3256<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3257 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3258
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3259<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3260<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3261 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3262 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3263
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3264<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3265<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3266
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3267<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3268 <tbody>
3269 <tr>
3270 <td>In0</td>
3271 <td>In1</td>
3272 <td>Out</td>
3273 </tr>
3274 <tr>
3275 <td>0</td>
3276 <td>0</td>
3277 <td>0</td>
3278 </tr>
3279 <tr>
3280 <td>0</td>
3281 <td>1</td>
3282 <td>0</td>
3283 </tr>
3284 <tr>
3285 <td>1</td>
3286 <td>0</td>
3287 <td>0</td>
3288 </tr>
3289 <tr>
3290 <td>1</td>
3291 <td>1</td>
3292 <td>1</td>
3293 </tr>
3294 </tbody>
3295</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3296
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3297<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3298<pre>
3299 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3300 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3301 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3302</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3303</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3304<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3305<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3306
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3307<div class="doc_text">
3308
3309<h5>Syntax:</h5>
3310<pre>
3311 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3312</pre>
3313
3314<h5>Overview:</h5>
3315<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3316 two operands.</p>
3317
3318<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3319<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3320 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3321 values. Both arguments must have identical types.</p>
3322
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3323<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3324<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3325
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3326<table border="1" cellspacing="0" cellpadding="4">
3327 <tbody>
3328 <tr>
3329 <td>In0</td>
3330 <td>In1</td>
3331 <td>Out</td>
3332 </tr>
3333 <tr>
3334 <td>0</td>
3335 <td>0</td>
3336 <td>0</td>
3337 </tr>
3338 <tr>
3339 <td>0</td>
3340 <td>1</td>
3341 <td>1</td>
3342 </tr>
3343 <tr>
3344 <td>1</td>
3345 <td>0</td>
3346 <td>1</td>
3347 </tr>
3348 <tr>
3349 <td>1</td>
3350 <td>1</td>
3351 <td>1</td>
3352 </tr>
3353 </tbody>
3354</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3355
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3356<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3357<pre>
3358 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3359 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3360 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3361</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3362
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3363</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3364
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3365<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3366<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3367Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3368
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3369<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3370
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3371<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3372<pre>
3373 &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3374</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3375
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3376<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3377<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3378 its two operands. The <tt>xor</tt> is used to implement the "one's
3379 complement" operation, which is the "~" operator in C.</p>
3380
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3381<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3382<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3383 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3384 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3385
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3386<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3387<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3388
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3389<table border="1" cellspacing="0" cellpadding="4">
3390 <tbody>
3391 <tr>
3392 <td>In0</td>
3393 <td>In1</td>
3394 <td>Out</td>
3395 </tr>
3396 <tr>
3397 <td>0</td>
3398 <td>0</td>
3399 <td>0</td>
3400 </tr>
3401 <tr>
3402 <td>0</td>
3403 <td>1</td>
3404 <td>1</td>
3405 </tr>
3406 <tr>
3407 <td>1</td>
3408 <td>0</td>
3409 <td>1</td>
3410 </tr>
3411 <tr>
3412 <td>1</td>
3413 <td>1</td>
3414 <td>0</td>
3415 </tr>
3416 </tbody>
3417</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3418
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3419<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3420<pre>
3421 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3422 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3423 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3424 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3425</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3426
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3427</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3428
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3429<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3430<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3431 <a name="vectorops">Vector Operations</a>
3432</div>
3433
3434<div class="doc_text">
3435
3436<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3437 target-independent manner. These instructions cover the element-access and
3438 vector-specific operations needed to process vectors effectively. While LLVM
3439 does directly support these vector operations, many sophisticated algorithms
3440 will want to use target-specific intrinsics to take full advantage of a
3441 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3442
3443</div>
3444
3445<!-- _______________________________________________________________________ -->
3446<div class="doc_subsubsection">
3447 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3448</div>
3449
3450<div class="doc_text">
3451
3452<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3453<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3454 &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 Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3455</pre>
3456
3457<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3458<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3459 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3460
3461
3462<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3463<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3464 of <a href="#t_vector">vector</a> type. The second operand is an index
3465 indicating the position from which to extract the element. The index may be
3466 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3467
3468<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3469<p>The result is a scalar of the same type as the element type of
3470 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3471 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3472 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3473
3474<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3475<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3476 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3477</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3478
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3479</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3480
3481<!-- _______________________________________________________________________ -->
3482<div class="doc_subsubsection">
3483 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3484</div>
3485
3486<div class="doc_text">
3487
3488<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3489<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]3490 &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 Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3491</pre>
3492
3493<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3494<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3495 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3496
3497<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3498<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3499 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3500 whose type must equal the element type of the first operand. The third
3501 operand is an index indicating the position at which to insert the value.
3502 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3503
3504<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3505<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3506 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3507 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3508 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3509
3510<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3511<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3512 %result = insertelement &lt;4 x i32&gt; %vec, i32 1, i32 0 <i>; yields &lt;4 x i32&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3513</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3514
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3515</div>
3516
3517<!-- _______________________________________________________________________ -->
3518<div class="doc_subsubsection">
3519 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3520</div>
3521
3522<div class="doc_text">
3523
3524<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3525<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3526 &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;m x i32&gt; &lt;mask&gt; <i>; yields &lt;m x &lt;ty&gt;&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3527</pre>
3528
3529<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3530<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3531 from two input vectors, returning a vector with the same element type as the
3532 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3533
3534<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3535<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3536 with types that match each other. The third argument is a shuffle mask whose
3537 element type is always 'i32'. The result of the instruction is a vector
3538 whose length is the same as the shuffle mask and whose element type is the
3539 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3540
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3541<p>The shuffle mask operand is required to be a constant vector with either
3542 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3543
3544<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3545<p>The elements of the two input vectors are numbered from left to right across
3546 both of the vectors. The shuffle mask operand specifies, for each element of
3547 the result vector, which element of the two input vectors the result element
3548 gets. The element selector may be undef (meaning "don't care") and the
3549 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3550
3551<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3552<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3553 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3554 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3555 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3556 &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.
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3557 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3558 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3559 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3560 &lt;8 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 &gt; <i>; yields &lt;8 x i32&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3561</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3562
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3563</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]3564
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3565<!-- ======================================================================= -->
3566<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3567 <a name="aggregateops">Aggregate Operations</a>
3568</div>
3569
3570<div class="doc_text">
3571
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3572<p>LLVM supports several instructions for working with aggregate values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3573
3574</div>
3575
3576<!-- _______________________________________________________________________ -->
3577<div class="doc_subsubsection">
3578 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3579</div>
3580
3581<div class="doc_text">
3582
3583<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3584<pre>
3585 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3586</pre>
3587
3588<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3589<p>The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3590 or array element from an aggregate value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3591
3592<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3593<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
3594 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3595 operands are constant indices to specify which value to extract in a similar
3596 manner as indices in a
3597 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3598
3599<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3600<p>The result is the value at the position in the aggregate specified by the
3601 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3602
3603<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3604<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3605 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3606</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3607
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3608</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3609
3610<!-- _______________________________________________________________________ -->
3611<div class="doc_subsubsection">
3612 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3613</div>
3614
3615<div class="doc_text">
3616
3617<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3618<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3619 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;val&gt;, &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3620</pre>
3621
3622<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3623<p>The '<tt>insertvalue</tt>' instruction inserts a value into a struct field or
3624 array element in an aggregate.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3625
3626
3627<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3628<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
3629 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3630 second operand is a first-class value to insert. The following operands are
3631 constant indices indicating the position at which to insert the value in a
3632 similar manner as indices in a
3633 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
3634 value to insert must have the same type as the value identified by the
3635 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3636
3637<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3638<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
3639 that of <tt>val</tt> except that the value at the position specified by the
3640 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3641
3642<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3643<pre>
Dan Gohman88ce1a52008-06-23 15:26:37 +0000[diff] [blame]3644 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3645</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3646
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3647</div>
3648
3649
3650<!-- ======================================================================= -->
3651<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3652 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3653</div>
3654
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3655<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3656
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3657<p>A key design point of an SSA-based representation is how it represents
3658 memory. In LLVM, no memory locations are in SSA form, which makes things
3659 very simple. This section describes how to read, write, allocate, and free
3660 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3661
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3662</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3663
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3664<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3665<div class="doc_subsubsection">
3666 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3667</div>
3668
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3669<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3670
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3671<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3672<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3673 &lt;result&gt; = malloc &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3674</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3675
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3676<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3677<p>The '<tt>malloc</tt>' instruction allocates memory from the system heap and
3678 returns a pointer to it. The object is always allocated in the generic
3679 address space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3680
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3681<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3682<p>The '<tt>malloc</tt>' instruction allocates
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3683 <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory from the operating
3684 system and returns a pointer of the appropriate type to the program. If
3685 "NumElements" is specified, it is the number of elements allocated, otherwise
3686 "NumElements" is defaulted to be one. If a constant alignment is specified,
3687 the value result of the allocation is guaranteed to be aligned to at least
3688 that boundary. If not specified, or if zero, the target can choose to align
3689 the allocation on any convenient boundary compatible with the type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3690
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3691<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3692
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3693<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3694<p>Memory is allocated using the system "<tt>malloc</tt>" function, and a
3695 pointer is returned. The result of a zero byte allocation is undefined. The
3696 result is null if there is insufficient memory available.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3697
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3698<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3699<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3700 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3701
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3702 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3703 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3704 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3705 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3706 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3707</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]3708
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3709<p>Note that the code generator does not yet respect the alignment value.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]3710
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3711</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3712
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3713<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3714<div class="doc_subsubsection">
3715 <a name="i_free">'<tt>free</tt>' Instruction</a>
3716</div>
3717
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3718<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3719
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3720<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3721<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3722 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3723</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3724
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3725<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3726<p>The '<tt>free</tt>' instruction returns memory back to the unused memory heap
3727 to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3728
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3729<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3730<p>'<tt>value</tt>' shall be a pointer value that points to a value that was
3731 allocated with the '<tt><a href="#i_malloc">malloc</a></tt>' instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3732
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3733<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3734<p>Access to the memory pointed to by the pointer is no longer defined after
3735 this instruction executes. If the pointer is null, the operation is a
3736 noop.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3737
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3738<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3739<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3740 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3741 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3742</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3743
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3744</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3745
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3746<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3747<div class="doc_subsubsection">
3748 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3749</div>
3750
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3751<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3752
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3753<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3754<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3755 &lt;result&gt; = alloca &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3756</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3757
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3758<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3759<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3760 currently executing function, to be automatically released when this function
3761 returns to its caller. The object is always allocated in the generic address
3762 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3763
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3764<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3765<p>The '<tt>alloca</tt>' instruction
3766 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
3767 runtime stack, returning a pointer of the appropriate type to the program.
3768 If "NumElements" is specified, it is the number of elements allocated,
3769 otherwise "NumElements" is defaulted to be one. If a constant alignment is
3770 specified, the value result of the allocation is guaranteed to be aligned to
3771 at least that boundary. If not specified, or if zero, the target can choose
3772 to align the allocation on any convenient boundary compatible with the
3773 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3774
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3775<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3776
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3777<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]3778<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3779 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
3780 memory is automatically released when the function returns. The
3781 '<tt>alloca</tt>' instruction is commonly used to represent automatic
3782 variables that must have an address available. When the function returns
3783 (either with the <tt><a href="#i_ret">ret</a></tt>
3784 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
3785 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3786
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3787<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3788<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3789 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3790 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3791 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3792 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3793</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3794
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3795</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3796
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3797<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3798<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3799Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3800
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3801<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3802
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3803<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3804<pre>
3805 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3806 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3807</pre>
3808
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3809<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3810<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3811
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3812<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3813<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
3814 from which to load. The pointer must point to
3815 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
3816 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
3817 number or order of execution of this <tt>load</tt> with other
3818 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3819 instructions. </p>
3820
3821<p>The optional constant "align" argument specifies the alignment of the
3822 operation (that is, the alignment of the memory address). A value of 0 or an
3823 omitted "align" argument means that the operation has the preferential
3824 alignment for the target. It is the responsibility of the code emitter to
3825 ensure that the alignment information is correct. Overestimating the
3826 alignment results in an undefined behavior. Underestimating the alignment may
3827 produce less efficient code. An alignment of 1 is always safe.</p>
3828
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3829<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3830<p>The location of memory pointed to is loaded. If the value being loaded is of
3831 scalar type then the number of bytes read does not exceed the minimum number
3832 of bytes needed to hold all bits of the type. For example, loading an
3833 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
3834 <tt>i20</tt> with a size that is not an integral number of bytes, the result
3835 is undefined if the value was not originally written using a store of the
3836 same type.</p>
3837
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3838<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3839<pre>
3840 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
3841 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3842 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3843</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3844
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3845</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3846
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3847<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3848<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3849Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3850
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]3851<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3852
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3853<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3854<pre>
3855 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3856 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3857</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3858
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3859<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3860<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3861
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3862<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3863<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
3864 and an address at which to store it. The type of the
3865 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
3866 the <a href="#t_firstclass">first class</a> type of the
3867 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
3868 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
3869 or order of execution of this <tt>store</tt> with other
3870 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3871 instructions.</p>
3872
3873<p>The optional constant "align" argument specifies the alignment of the
3874 operation (that is, the alignment of the memory address). A value of 0 or an
3875 omitted "align" argument means that the operation has the preferential
3876 alignment for the target. It is the responsibility of the code emitter to
3877 ensure that the alignment information is correct. Overestimating the
3878 alignment results in an undefined behavior. Underestimating the alignment may
3879 produce less efficient code. An alignment of 1 is always safe.</p>
3880
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3881<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3882<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
3883 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
3884 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
3885 does not exceed the minimum number of bytes needed to hold all bits of the
3886 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
3887 writing a value of a type like <tt>i20</tt> with a size that is not an
3888 integral number of bytes, it is unspecified what happens to the extra bits
3889 that do not belong to the type, but they will typically be overwritten.</p>
3890
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3891<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3892<pre>
3893 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]3894 store i32 3, i32* %ptr <i>; yields {void}</i>
3895 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3896</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3897
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3898</div>
3899
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3900<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3901<div class="doc_subsubsection">
3902 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3903</div>
3904
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3905<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3906
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3907<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3908<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3909 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]3910 &lt;result&gt; = getelementptr inbounds &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3911</pre>
3912
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3913<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3914<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
3915 subelement of an aggregate data structure. It performs address calculation
3916 only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3917
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3918<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3919<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]3920 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3921 elements of the aggregate object are indexed. The interpretation of each
3922 index is dependent on the type being indexed into. The first index always
3923 indexes the pointer value given as the first argument, the second index
3924 indexes a value of the type pointed to (not necessarily the value directly
3925 pointed to, since the first index can be non-zero), etc. The first type
3926 indexed into must be a pointer value, subsequent types can be arrays, vectors
3927 and structs. Note that subsequent types being indexed into can never be
3928 pointers, since that would require loading the pointer before continuing
3929 calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3930
3931<p>The type of each index argument depends on the type it is indexing into.
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]3932 When indexing into a (optionally packed) structure, only <tt>i32</tt> integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3933 <b>constants</b> are allowed. When indexing into an array, pointer or
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]3934 vector, integers of any width are allowed, and they are not required to be
3935 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3936
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3937<p>For example, let's consider a C code fragment and how it gets compiled to
3938 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3939
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3940<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3941<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3942struct RT {
3943 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3944 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3945 char C;
3946};
3947struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3948 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3949 double Y;
3950 struct RT Z;
3951};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3952
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3953int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3954 return &amp;s[1].Z.B[5][13];
3955}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3956</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3957</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3958
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3959<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3960
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3961<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3962<pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]3963%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3964%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3965
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]3966define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3967entry:
3968 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3969 ret i32* %reg
3970}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3971</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3972</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3973
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3974<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3975<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3976 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
3977 }</tt>' type, a structure. The second index indexes into the third element
3978 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3979 i8 }</tt>' type, another structure. The third index indexes into the second
3980 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
3981 array. The two dimensions of the array are subscripted into, yielding an
3982 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
3983 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3984
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3985<p>Note that it is perfectly legal to index partially through a structure,
3986 returning a pointer to an inner element. Because of this, the LLVM code for
3987 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3988
3989<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]3990 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3991 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3992 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3993 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3994 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3995 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3996 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3997 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3998</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3999
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4000<p>If the <tt>inbounds</tt> keyword is present, the result value of the
4001 <tt>getelementptr</tt> is undefined if the base pointer is not pointing
4002 into an allocated object, or if any of the addresses formed by successive
4003 addition of the offsets implied by the indices to the base address is
4004 outside of the allocated object into which the base pointer points.</p>
4005
4006<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4007 the base address with silently-wrapping two's complement arithmetic, and
4008 the result value of the <tt>getelementptr</tt> may be outside the object
4009 pointed to by the base pointer. The result value may not necessarily be
4010 used to access memory though, even if it happens to point into allocated
4011 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4012 section for more information.</p>
4013
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4014<p>The getelementptr instruction is often confusing. For some more insight into
4015 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4016
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4017<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4018<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4019 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4020 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4021 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4022 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4023 <i>; yields i8*:eptr</i>
4024 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]4025 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]4026 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4027</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4028
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4029</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4030
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4031<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4032<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4033</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4034
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4035<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4036
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4037<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4038 which all take a single operand and a type. They perform various bit
4039 conversions on the operand.</p>
4040
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4041</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4042
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4043<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4044<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4045 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4046</div>
4047<div class="doc_text">
4048
4049<h5>Syntax:</h5>
4050<pre>
4051 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4052</pre>
4053
4054<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4055<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4056 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4057
4058<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4059<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4060 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4061 size and type of the result, which must be
4062 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4063 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4064 allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4065
4066<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4067<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4068 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4069 source size must be larger than the destination size, <tt>trunc</tt> cannot
4070 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4071
4072<h5>Example:</h5>
4073<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4074 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4075 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4076 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4077</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4078
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4079</div>
4080
4081<!-- _______________________________________________________________________ -->
4082<div class="doc_subsubsection">
4083 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4084</div>
4085<div class="doc_text">
4086
4087<h5>Syntax:</h5>
4088<pre>
4089 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4090</pre>
4091
4092<h5>Overview:</h5>
4093<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4094 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4095
4096
4097<h5>Arguments:</h5>
4098<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4099 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4100 also be of <a href="#t_integer">integer</a> type. The bit size of the
4101 <tt>value</tt> must be smaller than the bit size of the destination type,
4102 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4103
4104<h5>Semantics:</h5>
4105<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4106 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4107
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]4108<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4109
4110<h5>Example:</h5>
4111<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4112 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4113 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4114</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4115
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4116</div>
4117
4118<!-- _______________________________________________________________________ -->
4119<div class="doc_subsubsection">
4120 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4121</div>
4122<div class="doc_text">
4123
4124<h5>Syntax:</h5>
4125<pre>
4126 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4127</pre>
4128
4129<h5>Overview:</h5>
4130<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4131
4132<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4133<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
4134 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4135 also be of <a href="#t_integer">integer</a> type. The bit size of the
4136 <tt>value</tt> must be smaller than the bit size of the destination type,
4137 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4138
4139<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4140<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4141 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4142 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4143
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4144<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4145
4146<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4147<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4148 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4149 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4150</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4151
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4152</div>
4153
4154<!-- _______________________________________________________________________ -->
4155<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4156 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4157</div>
4158
4159<div class="doc_text">
4160
4161<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4162<pre>
4163 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4164</pre>
4165
4166<h5>Overview:</h5>
4167<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4168 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4169
4170<h5>Arguments:</h5>
4171<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4172 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4173 to cast it to. The size of <tt>value</tt> must be larger than the size of
4174 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
4175 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4176
4177<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4178<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
4179 <a href="#t_floating">floating point</a> type to a smaller
4180 <a href="#t_floating">floating point</a> type. If the value cannot fit
4181 within the destination type, <tt>ty2</tt>, then the results are
4182 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4183
4184<h5>Example:</h5>
4185<pre>
4186 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4187 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4188</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4189
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4190</div>
4191
4192<!-- _______________________________________________________________________ -->
4193<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4194 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4195</div>
4196<div class="doc_text">
4197
4198<h5>Syntax:</h5>
4199<pre>
4200 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4201</pre>
4202
4203<h5>Overview:</h5>
4204<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4205 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4206
4207<h5>Arguments:</h5>
4208<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4209 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4210 a <a href="#t_floating">floating point</a> type to cast it to. The source
4211 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4212
4213<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4214<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4215 <a href="#t_floating">floating point</a> type to a larger
4216 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4217 used to make a <i>no-op cast</i> because it always changes bits. Use
4218 <tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4219
4220<h5>Example:</h5>
4221<pre>
4222 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4223 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4224</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4225
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4226</div>
4227
4228<!-- _______________________________________________________________________ -->
4229<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]4230 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4231</div>
4232<div class="doc_text">
4233
4234<h5>Syntax:</h5>
4235<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4236 &lt;result&gt; = fptoui &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4237</pre>
4238
4239<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4240<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4241 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4242
4243<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4244<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4245 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4246 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4247 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4248 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4249
4250<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4251<p>The '<tt>fptoui</tt>' instruction converts its
4252 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4253 towards zero) unsigned integer value. If the value cannot fit
4254 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4255
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4256<h5>Example:</h5>
4257<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4258 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4259 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4260 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4261</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4262
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4263</div>
4264
4265<!-- _______________________________________________________________________ -->
4266<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4267 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4268</div>
4269<div class="doc_text">
4270
4271<h5>Syntax:</h5>
4272<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4273 &lt;result&gt; = fptosi &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4274</pre>
4275
4276<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4277<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4278 <a href="#t_floating">floating point</a> <tt>value</tt> to
4279 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4280
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4281<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4282<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4283 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4284 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4285 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4286 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4287
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4288<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4289<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4290 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4291 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4292 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4293
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4294<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4295<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4296 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4297 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4298 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4299</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4300
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4301</div>
4302
4303<!-- _______________________________________________________________________ -->
4304<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4305 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4306</div>
4307<div class="doc_text">
4308
4309<h5>Syntax:</h5>
4310<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4311 &lt;result&gt; = uitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4312</pre>
4313
4314<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4315<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4316 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4317
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4318<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4319<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4320 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4321 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4322 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4323 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4324
4325<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4326<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4327 integer quantity and converts it to the corresponding floating point
4328 value. If the value cannot fit in the floating point value, the results are
4329 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4330
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4331<h5>Example:</h5>
4332<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4333 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4334 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4335</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4336
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4337</div>
4338
4339<!-- _______________________________________________________________________ -->
4340<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4341 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4342</div>
4343<div class="doc_text">
4344
4345<h5>Syntax:</h5>
4346<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4347 &lt;result&gt; = sitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4348</pre>
4349
4350<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4351<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4352 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4353
4354<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4355<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4356 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4357 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4358 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4359 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4360
4361<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4362<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4363 quantity and converts it to the corresponding floating point value. If the
4364 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4365
4366<h5>Example:</h5>
4367<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4368 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4369 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4370</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4371
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4372</div>
4373
4374<!-- _______________________________________________________________________ -->
4375<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4376 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4377</div>
4378<div class="doc_text">
4379
4380<h5>Syntax:</h5>
4381<pre>
4382 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4383</pre>
4384
4385<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4386<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4387 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4388
4389<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4390<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4391 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4392 <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4393
4394<h5>Semantics:</h5>
4395<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4396 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4397 truncating or zero extending that value to the size of the integer type. If
4398 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4399 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4400 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4401 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4402
4403<h5>Example:</h5>
4404<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4405 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4406 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4407</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4408
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4409</div>
4410
4411<!-- _______________________________________________________________________ -->
4412<div class="doc_subsubsection">
4413 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4414</div>
4415<div class="doc_text">
4416
4417<h5>Syntax:</h5>
4418<pre>
4419 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4420</pre>
4421
4422<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4423<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4424 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4425
4426<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4427<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4428 value to cast, and a type to cast it to, which must be a
4429 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4430
4431<h5>Semantics:</h5>
4432<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4433 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4434 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4435 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4436 than the size of a pointer then a zero extension is done. If they are the
4437 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4438
4439<h5>Example:</h5>
4440<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4441 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4442 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4443 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4444</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4445
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4446</div>
4447
4448<!-- _______________________________________________________________________ -->
4449<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4450 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4451</div>
4452<div class="doc_text">
4453
4454<h5>Syntax:</h5>
4455<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4456 &lt;result&gt; = bitcast &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4457</pre>
4458
4459<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4460<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4461 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4462
4463<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4464<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4465 non-aggregate first class value, and a type to cast it to, which must also be
4466 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4467 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4468 identical. If the source type is a pointer, the destination type must also be
4469 a pointer. This instruction supports bitwise conversion of vectors to
4470 integers and to vectors of other types (as long as they have the same
4471 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4472
4473<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4474<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4475 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4476 this conversion. The conversion is done as if the <tt>value</tt> had been
4477 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4478 be converted to other pointer types with this instruction. To convert
4479 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4480 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4481
4482<h5>Example:</h5>
4483<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4484 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4485 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4486 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4487</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4488
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4489</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4490
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4491<!-- ======================================================================= -->
4492<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4493
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4494<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4495
4496<p>The instructions in this category are the "miscellaneous" instructions, which
4497 defy better classification.</p>
4498
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4499</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4500
4501<!-- _______________________________________________________________________ -->
4502<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4503</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4504
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4505<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4506
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4507<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4508<pre>
4509 &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4510</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4511
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4512<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4513<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4514 boolean values based on comparison of its two integer, integer vector, or
4515 pointer operands.</p>
4516
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4517<h5>Arguments:</h5>
4518<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4519 the condition code indicating the kind of comparison to perform. It is not a
4520 value, just a keyword. The possible condition code are:</p>
4521
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4522<ol>
4523 <li><tt>eq</tt>: equal</li>
4524 <li><tt>ne</tt>: not equal </li>
4525 <li><tt>ugt</tt>: unsigned greater than</li>
4526 <li><tt>uge</tt>: unsigned greater or equal</li>
4527 <li><tt>ult</tt>: unsigned less than</li>
4528 <li><tt>ule</tt>: unsigned less or equal</li>
4529 <li><tt>sgt</tt>: signed greater than</li>
4530 <li><tt>sge</tt>: signed greater or equal</li>
4531 <li><tt>slt</tt>: signed less than</li>
4532 <li><tt>sle</tt>: signed less or equal</li>
4533</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4534
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]4535<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4536 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4537 typed. They must also be identical types.</p>
4538
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4539<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4540<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4541 condition code given as <tt>cond</tt>. The comparison performed always yields
4542 either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt>
4543 result, as follows:</p>
4544
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4545<ol>
4546 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4547 <tt>false</tt> otherwise. No sign interpretation is necessary or
4548 performed.</li>
4549
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4550 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4551 <tt>false</tt> otherwise. No sign interpretation is necessary or
4552 performed.</li>
4553
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4554 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4555 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4556
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4557 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4558 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4559 to <tt>op2</tt>.</li>
4560
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4561 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4562 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4563
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4564 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4565 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4566
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4567 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4568 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4569
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4570 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4571 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4572 to <tt>op2</tt>.</li>
4573
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4574 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4575 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4576
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4577 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4578 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4579</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4580
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4581<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4582 values are compared as if they were integers.</p>
4583
4584<p>If the operands are integer vectors, then they are compared element by
4585 element. The result is an <tt>i1</tt> vector with the same number of elements
4586 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4587
4588<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4589<pre>
4590 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4591 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4592 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4593 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4594 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4595 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4596</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4597
4598<p>Note that the code generator does not yet support vector types with
4599 the <tt>icmp</tt> instruction.</p>
4600
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4601</div>
4602
4603<!-- _______________________________________________________________________ -->
4604<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4605</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4606
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4607<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4608
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4609<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4610<pre>
4611 &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4612</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4613
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4614<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4615<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4616 values based on comparison of its operands.</p>
4617
4618<p>If the operands are floating point scalars, then the result type is a boolean
4619(<a href="#t_primitive"><tt>i1</tt></a>).</p>
4620
4621<p>If the operands are floating point vectors, then the result type is a vector
4622 of boolean with the same number of elements as the operands being
4623 compared.</p>
4624
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4625<h5>Arguments:</h5>
4626<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4627 the condition code indicating the kind of comparison to perform. It is not a
4628 value, just a keyword. The possible condition code are:</p>
4629
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4630<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4631 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4632 <li><tt>oeq</tt>: ordered and equal</li>
4633 <li><tt>ogt</tt>: ordered and greater than </li>
4634 <li><tt>oge</tt>: ordered and greater than or equal</li>
4635 <li><tt>olt</tt>: ordered and less than </li>
4636 <li><tt>ole</tt>: ordered and less than or equal</li>
4637 <li><tt>one</tt>: ordered and not equal</li>
4638 <li><tt>ord</tt>: ordered (no nans)</li>
4639 <li><tt>ueq</tt>: unordered or equal</li>
4640 <li><tt>ugt</tt>: unordered or greater than </li>
4641 <li><tt>uge</tt>: unordered or greater than or equal</li>
4642 <li><tt>ult</tt>: unordered or less than </li>
4643 <li><tt>ule</tt>: unordered or less than or equal</li>
4644 <li><tt>une</tt>: unordered or not equal</li>
4645 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4646 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4647</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4648
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4649<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4650 <i>unordered</i> means that either operand may be a QNAN.</p>
4651
4652<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
4653 a <a href="#t_floating">floating point</a> type or
4654 a <a href="#t_vector">vector</a> of floating point type. They must have
4655 identical types.</p>
4656
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4657<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4658<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4659 according to the condition code given as <tt>cond</tt>. If the operands are
4660 vectors, then the vectors are compared element by element. Each comparison
4661 performed always yields an <a href="#t_primitive">i1</a> result, as
4662 follows:</p>
4663
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4664<ol>
4665 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4666
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4667 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4668 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4669
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4670 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4671 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
4672
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4673 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4674 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4675
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4676 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4677 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4678
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4679 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4680 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4681
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4682 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4683 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4684
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4685 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4686
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4687 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4688 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4689
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4690 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4691 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4692
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4693 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4694 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4695
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4696 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4697 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4698
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4699 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4700 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4701
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4702 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4703 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4704
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4705 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4706
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4707 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4708</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4709
4710<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4711<pre>
4712 &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4713 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4714 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4715 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4716</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4717
4718<p>Note that the code generator does not yet support vector types with
4719 the <tt>fcmp</tt> instruction.</p>
4720
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4721</div>
4722
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4723<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4724<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4725 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4726</div>
4727
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4728<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4729
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4730<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4731<pre>
4732 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
4733</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4734
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4735<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4736<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
4737 SSA graph representing the function.</p>
4738
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4739<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4740<p>The type of the incoming values is specified with the first type field. After
4741 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
4742 one pair for each predecessor basic block of the current block. Only values
4743 of <a href="#t_firstclass">first class</a> type may be used as the value
4744 arguments to the PHI node. Only labels may be used as the label
4745 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4746
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4747<p>There must be no non-phi instructions between the start of a basic block and
4748 the PHI instructions: i.e. PHI instructions must be first in a basic
4749 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4750
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4751<p>For the purposes of the SSA form, the use of each incoming value is deemed to
4752 occur on the edge from the corresponding predecessor block to the current
4753 block (but after any definition of an '<tt>invoke</tt>' instruction's return
4754 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]4755
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4756<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4757<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4758 specified by the pair corresponding to the predecessor basic block that
4759 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4760
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4761<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4762<pre>
4763Loop: ; Infinite loop that counts from 0 on up...
4764 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4765 %nextindvar = add i32 %indvar, 1
4766 br label %Loop
4767</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4768
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4769</div>
4770
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4771<!-- _______________________________________________________________________ -->
4772<div class="doc_subsubsection">
4773 <a name="i_select">'<tt>select</tt>' Instruction</a>
4774</div>
4775
4776<div class="doc_text">
4777
4778<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4779<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4780 &lt;result&gt; = select <i>selty</i> &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
4781
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4782 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4783</pre>
4784
4785<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4786<p>The '<tt>select</tt>' instruction is used to choose one value based on a
4787 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4788
4789
4790<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4791<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
4792 values indicating the condition, and two values of the
4793 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
4794 vectors and the condition is a scalar, then entire vectors are selected, not
4795 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4796
4797<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4798<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
4799 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4800
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4801<p>If the condition is a vector of i1, then the value arguments must be vectors
4802 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4803
4804<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4805<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4806 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4807</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4808
4809<p>Note that the code generator does not yet support conditions
4810 with vector type.</p>
4811
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4812</div>
4813
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]4814<!-- _______________________________________________________________________ -->
4815<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4816 <a name="i_call">'<tt>call</tt>' Instruction</a>
4817</div>
4818
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4819<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4820
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4821<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4822<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4823 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4824</pre>
4825
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4826<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4827<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4828
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4829<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4830<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4831
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4832<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4833 <li>The optional "tail" marker indicates whether the callee function accesses
4834 any allocas or varargs in the caller. If the "tail" marker is present,
4835 the function call is eligible for tail call optimization. Note that calls
4836 may be marked "tail" even if they do not occur before
4837 a <a href="#i_ret"><tt>ret</tt></a> instruction.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4838
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4839 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
4840 convention</a> the call should use. If none is specified, the call
4841 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4842
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4843 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4844 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
4845 '<tt>inreg</tt>' attributes are valid here.</li>
4846
4847 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
4848 type of the return value. Functions that return no value are marked
4849 <tt><a href="#t_void">void</a></tt>.</li>
4850
4851 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
4852 being invoked. The argument types must match the types implied by this
4853 signature. This type can be omitted if the function is not varargs and if
4854 the function type does not return a pointer to a function.</li>
4855
4856 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4857 be invoked. In most cases, this is a direct function invocation, but
4858 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
4859 to function value.</li>
4860
4861 <li>'<tt>function args</tt>': argument list whose types match the function
4862 signature argument types. All arguments must be of
4863 <a href="#t_firstclass">first class</a> type. If the function signature
4864 indicates the function accepts a variable number of arguments, the extra
4865 arguments can be specified.</li>
4866
4867 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
4868 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4869 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4870</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4871
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4872<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4873<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
4874 a specified function, with its incoming arguments bound to the specified
4875 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
4876 function, control flow continues with the instruction after the function
4877 call, and the return value of the function is bound to the result
4878 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4879
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4880<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4881<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4882 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]4883 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4884 %X = tail call i32 @foo() <i>; yields i32</i>
4885 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4886 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4887
4888 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4889 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]4890 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4891 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]4892 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]4893 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4894</pre>
4895
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4896</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4897
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4898<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4899<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4900 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4901</div>
4902
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4903<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4904
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4905<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4906<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4907 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4908</pre>
4909
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4910<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4911<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4912 the "variable argument" area of a function call. It is used to implement the
4913 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4914
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4915<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4916<p>This instruction takes a <tt>va_list*</tt> value and the type of the
4917 argument. It returns a value of the specified argument type and increments
4918 the <tt>va_list</tt> to point to the next argument. The actual type
4919 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4920
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4921<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4922<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
4923 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
4924 to the next argument. For more information, see the variable argument
4925 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4926
4927<p>It is legal for this instruction to be called in a function which does not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4928 take a variable number of arguments, for example, the <tt>vfprintf</tt>
4929 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4930
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4931<p><tt>va_arg</tt> is an LLVM instruction instead of
4932 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
4933 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4934
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4935<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4936<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4937
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4938<p>Note that the code generator does not yet fully support va_arg on many
4939 targets. Also, it does not currently support va_arg with aggregate types on
4940 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]4941
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4942</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4943
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4944<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4945<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4946<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4947
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4948<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4949
4950<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4951 well known names and semantics and are required to follow certain
4952 restrictions. Overall, these intrinsics represent an extension mechanism for
4953 the LLVM language that does not require changing all of the transformations
4954 in LLVM when adding to the language (or the bitcode reader/writer, the
4955 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4956
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4957<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4958 prefix is reserved in LLVM for intrinsic names; thus, function names may not
4959 begin with this prefix. Intrinsic functions must always be external
4960 functions: you cannot define the body of intrinsic functions. Intrinsic
4961 functions may only be used in call or invoke instructions: it is illegal to
4962 take the address of an intrinsic function. Additionally, because intrinsic
4963 functions are part of the LLVM language, it is required if any are added that
4964 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4965
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4966<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
4967 family of functions that perform the same operation but on different data
4968 types. Because LLVM can represent over 8 million different integer types,
4969 overloading is used commonly to allow an intrinsic function to operate on any
4970 integer type. One or more of the argument types or the result type can be
4971 overloaded to accept any integer type. Argument types may also be defined as
4972 exactly matching a previous argument's type or the result type. This allows
4973 an intrinsic function which accepts multiple arguments, but needs all of them
4974 to be of the same type, to only be overloaded with respect to a single
4975 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4976
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4977<p>Overloaded intrinsics will have the names of its overloaded argument types
4978 encoded into its function name, each preceded by a period. Only those types
4979 which are overloaded result in a name suffix. Arguments whose type is matched
4980 against another type do not. For example, the <tt>llvm.ctpop</tt> function
4981 can take an integer of any width and returns an integer of exactly the same
4982 integer width. This leads to a family of functions such as
4983 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
4984 %val)</tt>. Only one type, the return type, is overloaded, and only one type
4985 suffix is required. Because the argument's type is matched against the return
4986 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4987
4988<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4989 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4990
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4991</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4992
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4993<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4994<div class="doc_subsection">
4995 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4996</div>
4997
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4998<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4999
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5000<p>Variable argument support is defined in LLVM with
5001 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5002 intrinsic functions. These functions are related to the similarly named
5003 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5004
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5005<p>All of these functions operate on arguments that use a target-specific value
5006 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5007 not define what this type is, so all transformations should be prepared to
5008 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5009
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]5010<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5011 instruction and the variable argument handling intrinsic functions are
5012 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5013
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5014<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5015<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5016define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5017 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5018 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5019 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5020 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5021
5022 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5023 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5024
5025 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5026 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5027 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5028 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5029 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5030
5031 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5032 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5033 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5034}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5035
5036declare void @llvm.va_start(i8*)
5037declare void @llvm.va_copy(i8*, i8*)
5038declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5039</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5040</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5041
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5042</div>
5043
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5044<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5045<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5046 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5047</div>
5048
5049
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5050<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5051
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5052<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5053<pre>
5054 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5055</pre>
5056
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5057<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5058<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5059 for subsequent use by <tt><a href="#i_va_arg">va_arg</a></tt>.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5060
5061<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5062<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5063
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5064<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5065<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5066 macro available in C. In a target-dependent way, it initializes
5067 the <tt>va_list</tt> element to which the argument points, so that the next
5068 call to <tt>va_arg</tt> will produce the first variable argument passed to
5069 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5070 need to know the last argument of the function as the compiler can figure
5071 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5072
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5073</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5074
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5075<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5076<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5077 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5078</div>
5079
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5080<div class="doc_text">
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5081
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5082<h5>Syntax:</h5>
5083<pre>
5084 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5085</pre>
5086
5087<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5088<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5089 which has been initialized previously
5090 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5091 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5092
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5093<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5094<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5095
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5096<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5097<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5098 macro available in C. In a target-dependent way, it destroys
5099 the <tt>va_list</tt> element to which the argument points. Calls
5100 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5101 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5102 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5103
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5104</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5105
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5106<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5107<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5108 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5109</div>
5110
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5111<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5112
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5113<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5114<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5115 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5116</pre>
5117
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5118<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5119<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5120 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5121
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5122<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5123<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5124 The second argument is a pointer to a <tt>va_list</tt> element to copy
5125 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5126
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5127<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5128<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5129 macro available in C. In a target-dependent way, it copies the
5130 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5131 element. This intrinsic is necessary because
5132 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5133 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5134
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5135</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5136
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5137<!-- ======================================================================= -->
5138<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5139 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5140</div>
5141
5142<div class="doc_text">
5143
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5144<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5145Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5146intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5147roots on the stack</a>, as well as garbage collector implementations that
5148require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5149barriers. Front-ends for type-safe garbage collected languages should generate
5150these intrinsics to make use of the LLVM garbage collectors. For more details,
5151see <a href="GarbageCollection.html">Accurate Garbage Collection with
5152LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5153
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5154<p>The garbage collection intrinsics only operate on objects in the generic
5155 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5156
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5157</div>
5158
5159<!-- _______________________________________________________________________ -->
5160<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5161 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5162</div>
5163
5164<div class="doc_text">
5165
5166<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5167<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5168 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5169</pre>
5170
5171<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]5172<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5173 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5174
5175<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5176<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5177 root pointer. The second pointer (which must be either a constant or a
5178 global value address) contains the meta-data to be associated with the
5179 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5180
5181<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]5182<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5183 location. At compile-time, the code generator generates information to allow
5184 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5185 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5186 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5187
5188</div>
5189
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5190<!-- _______________________________________________________________________ -->
5191<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5192 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5193</div>
5194
5195<div class="doc_text">
5196
5197<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5198<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5199 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5200</pre>
5201
5202<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5203<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5204 locations, allowing garbage collector implementations that require read
5205 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5206
5207<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5208<p>The second argument is the address to read from, which should be an address
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5209 allocated from the garbage collector. The first object is a pointer to the
5210 start of the referenced object, if needed by the language runtime (otherwise
5211 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5212
5213<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5214<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5215 instruction, but may be replaced with substantially more complex code by the
5216 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5217 may only be used in a function which <a href="#gc">specifies a GC
5218 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5219
5220</div>
5221
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5222<!-- _______________________________________________________________________ -->
5223<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5224 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5225</div>
5226
5227<div class="doc_text">
5228
5229<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5230<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5231 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5232</pre>
5233
5234<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5235<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5236 locations, allowing garbage collector implementations that require write
5237 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5238
5239<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5240<p>The first argument is the reference to store, the second is the start of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5241 object to store it to, and the third is the address of the field of Obj to
5242 store to. If the runtime does not require a pointer to the object, Obj may
5243 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5244
5245<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5246<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5247 instruction, but may be replaced with substantially more complex code by the
5248 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5249 may only be used in a function which <a href="#gc">specifies a GC
5250 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5251
5252</div>
5253
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5254<!-- ======================================================================= -->
5255<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5256 <a name="int_codegen">Code Generator Intrinsics</a>
5257</div>
5258
5259<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5260
5261<p>These intrinsics are provided by LLVM to expose special features that may
5262 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5263
5264</div>
5265
5266<!-- _______________________________________________________________________ -->
5267<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5268 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5269</div>
5270
5271<div class="doc_text">
5272
5273<h5>Syntax:</h5>
5274<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5275 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5276</pre>
5277
5278<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5279<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5280 target-specific value indicating the return address of the current function
5281 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5282
5283<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5284<p>The argument to this intrinsic indicates which function to return the address
5285 for. Zero indicates the calling function, one indicates its caller, etc.
5286 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5287
5288<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5289<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5290 indicating the return address of the specified call frame, or zero if it
5291 cannot be identified. The value returned by this intrinsic is likely to be
5292 incorrect or 0 for arguments other than zero, so it should only be used for
5293 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5294
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5295<p>Note that calling this intrinsic does not prevent function inlining or other
5296 aggressive transformations, so the value returned may not be that of the
5297 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5298
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5299</div>
5300
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5301<!-- _______________________________________________________________________ -->
5302<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5303 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5304</div>
5305
5306<div class="doc_text">
5307
5308<h5>Syntax:</h5>
5309<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5310 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5311</pre>
5312
5313<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5314<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5315 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5316
5317<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5318<p>The argument to this intrinsic indicates which function to return the frame
5319 pointer for. Zero indicates the calling function, one indicates its caller,
5320 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5321
5322<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5323<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5324 indicating the frame address of the specified call frame, or zero if it
5325 cannot be identified. The value returned by this intrinsic is likely to be
5326 incorrect or 0 for arguments other than zero, so it should only be used for
5327 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5328
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5329<p>Note that calling this intrinsic does not prevent function inlining or other
5330 aggressive transformations, so the value returned may not be that of the
5331 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5332
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5333</div>
5334
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5335<!-- _______________________________________________________________________ -->
5336<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5337 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5338</div>
5339
5340<div class="doc_text">
5341
5342<h5>Syntax:</h5>
5343<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5344 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5345</pre>
5346
5347<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5348<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5349 of the function stack, for use
5350 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5351 useful for implementing language features like scoped automatic variable
5352 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5353
5354<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5355<p>This intrinsic returns a opaque pointer value that can be passed
5356 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5357 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5358 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5359 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5360 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5361 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5362
5363</div>
5364
5365<!-- _______________________________________________________________________ -->
5366<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5367 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5368</div>
5369
5370<div class="doc_text">
5371
5372<h5>Syntax:</h5>
5373<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5374 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5375</pre>
5376
5377<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5378<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5379 the function stack to the state it was in when the
5380 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5381 executed. This is useful for implementing language features like scoped
5382 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5383
5384<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5385<p>See the description
5386 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5387
5388</div>
5389
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5390<!-- _______________________________________________________________________ -->
5391<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5392 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5393</div>
5394
5395<div class="doc_text">
5396
5397<h5>Syntax:</h5>
5398<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5399 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5400</pre>
5401
5402<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5403<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5404 insert a prefetch instruction if supported; otherwise, it is a noop.
5405 Prefetches have no effect on the behavior of the program but can change its
5406 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5407
5408<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5409<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5410 specifier determining if the fetch should be for a read (0) or write (1),
5411 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5412 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5413 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5414
5415<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5416<p>This intrinsic does not modify the behavior of the program. In particular,
5417 prefetches cannot trap and do not produce a value. On targets that support
5418 this intrinsic, the prefetch can provide hints to the processor cache for
5419 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5420
5421</div>
5422
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5423<!-- _______________________________________________________________________ -->
5424<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5425 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5426</div>
5427
5428<div class="doc_text">
5429
5430<h5>Syntax:</h5>
5431<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5432 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5433</pre>
5434
5435<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5436<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5437 Counter (PC) in a region of code to simulators and other tools. The method
5438 is target specific, but it is expected that the marker will use exported
5439 symbols to transmit the PC of the marker. The marker makes no guarantees
5440 that it will remain with any specific instruction after optimizations. It is
5441 possible that the presence of a marker will inhibit optimizations. The
5442 intended use is to be inserted after optimizations to allow correlations of
5443 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5444
5445<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5446<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5447
5448<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5449<p>This intrinsic does not modify the behavior of the program. Backends that do
5450 not support this intrinisic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5451
5452</div>
5453
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5454<!-- _______________________________________________________________________ -->
5455<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5456 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5457</div>
5458
5459<div class="doc_text">
5460
5461<h5>Syntax:</h5>
5462<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5463 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5464</pre>
5465
5466<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5467<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5468 counter register (or similar low latency, high accuracy clocks) on those
5469 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5470 should map to RPCC. As the backing counters overflow quickly (on the order
5471 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5472
5473<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5474<p>When directly supported, reading the cycle counter should not modify any
5475 memory. Implementations are allowed to either return a application specific
5476 value or a system wide value. On backends without support, this is lowered
5477 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5478
5479</div>
5480
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5481<!-- ======================================================================= -->
5482<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5483 <a name="int_libc">Standard C Library Intrinsics</a>
5484</div>
5485
5486<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5487
5488<p>LLVM provides intrinsics for a few important standard C library functions.
5489 These intrinsics allow source-language front-ends to pass information about
5490 the alignment of the pointer arguments to the code generator, providing
5491 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5492
5493</div>
5494
5495<!-- _______________________________________________________________________ -->
5496<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5497 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5498</div>
5499
5500<div class="doc_text">
5501
5502<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5503<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
5504 integer bit width. Not all targets support all bit widths however.</p>
5505
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5506<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5507 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5508 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5509 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5510 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5511 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5512 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5513 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5514 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5515</pre>
5516
5517<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5518<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5519 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5520
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5521<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5522 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5523
5524<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5525<p>The first argument is a pointer to the destination, the second is a pointer
5526 to the source. The third argument is an integer argument specifying the
5527 number of bytes to copy, and the fourth argument is the alignment of the
5528 source and destination locations.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5529
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5530<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5531 then the caller guarantees that both the source and destination pointers are
5532 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5533
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5534<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5535<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5536 source location to the destination location, which are not allowed to
5537 overlap. It copies "len" bytes of memory over. If the argument is known to
5538 be aligned to some boundary, this can be specified as the fourth argument,
5539 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5540
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5541</div>
5542
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5543<!-- _______________________________________________________________________ -->
5544<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5545 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5546</div>
5547
5548<div class="doc_text">
5549
5550<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5551<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5552 width. Not all targets support all bit widths however.</p>
5553
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5554<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5555 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5556 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5557 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5558 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5559 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5560 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5561 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5562 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5563</pre>
5564
5565<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5566<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5567 source location to the destination location. It is similar to the
5568 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5569 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5570
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5571<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5572 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5573
5574<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5575<p>The first argument is a pointer to the destination, the second is a pointer
5576 to the source. The third argument is an integer argument specifying the
5577 number of bytes to copy, and the fourth argument is the alignment of the
5578 source and destination locations.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5579
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5580<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5581 then the caller guarantees that the source and destination pointers are
5582 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5583
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5584<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5585<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5586 source location to the destination location, which may overlap. It copies
5587 "len" bytes of memory over. If the argument is known to be aligned to some
5588 boundary, this can be specified as the fourth argument, otherwise it should
5589 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5590
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5591</div>
5592
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5593<!-- _______________________________________________________________________ -->
5594<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5595 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5596</div>
5597
5598<div class="doc_text">
5599
5600<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5601<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5602 width. Not all targets support all bit widths however.</p>
5603
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5604<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5605 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5606 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5607 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5608 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5609 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5610 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5611 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5612 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5613</pre>
5614
5615<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5616<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
5617 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5618
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5619<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
5620 intrinsic does not return a value, and takes an extra alignment argument.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5621
5622<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5623<p>The first argument is a pointer to the destination to fill, the second is the
5624 byte value to fill it with, the third argument is an integer argument
5625 specifying the number of bytes to fill, and the fourth argument is the known
5626 alignment of destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5627
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5628<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5629 then the caller guarantees that the destination pointer is aligned to that
5630 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5631
5632<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5633<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
5634 at the destination location. If the argument is known to be aligned to some
5635 boundary, this can be specified as the fourth argument, otherwise it should
5636 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5637
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5638</div>
5639
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5640<!-- _______________________________________________________________________ -->
5641<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5642 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5643</div>
5644
5645<div class="doc_text">
5646
5647<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5648<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
5649 floating point or vector of floating point type. Not all targets support all
5650 types however.</p>
5651
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5652<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5653 declare float @llvm.sqrt.f32(float %Val)
5654 declare double @llvm.sqrt.f64(double %Val)
5655 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5656 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5657 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5658</pre>
5659
5660<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5661<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
5662 returning the same value as the libm '<tt>sqrt</tt>' functions would.
5663 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
5664 behavior for negative numbers other than -0.0 (which allows for better
5665 optimization, because there is no need to worry about errno being
5666 set). <tt>llvm.sqrt(-0.0)</tt> is defined to return -0.0 like IEEE sqrt.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5667
5668<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5669<p>The argument and return value are floating point numbers of the same
5670 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5671
5672<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5673<p>This function returns the sqrt of the specified operand if it is a
5674 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5675
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5676</div>
5677
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5678<!-- _______________________________________________________________________ -->
5679<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5680 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5681</div>
5682
5683<div class="doc_text">
5684
5685<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5686<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
5687 floating point or vector of floating point type. Not all targets support all
5688 types however.</p>
5689
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5690<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5691 declare float @llvm.powi.f32(float %Val, i32 %power)
5692 declare double @llvm.powi.f64(double %Val, i32 %power)
5693 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5694 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5695 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5696</pre>
5697
5698<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5699<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5700 specified (positive or negative) power. The order of evaluation of
5701 multiplications is not defined. When a vector of floating point type is
5702 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5703
5704<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5705<p>The second argument is an integer power, and the first is a value to raise to
5706 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5707
5708<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5709<p>This function returns the first value raised to the second power with an
5710 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5711
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5712</div>
5713
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5714<!-- _______________________________________________________________________ -->
5715<div class="doc_subsubsection">
5716 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5717</div>
5718
5719<div class="doc_text">
5720
5721<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5722<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5723 floating point or vector of floating point type. Not all targets support all
5724 types however.</p>
5725
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5726<pre>
5727 declare float @llvm.sin.f32(float %Val)
5728 declare double @llvm.sin.f64(double %Val)
5729 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5730 declare fp128 @llvm.sin.f128(fp128 %Val)
5731 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5732</pre>
5733
5734<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5735<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5736
5737<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5738<p>The argument and return value are floating point numbers of the same
5739 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5740
5741<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5742<p>This function returns the sine of the specified operand, returning the same
5743 values as the libm <tt>sin</tt> functions would, and handles error conditions
5744 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5745
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5746</div>
5747
5748<!-- _______________________________________________________________________ -->
5749<div class="doc_subsubsection">
5750 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5751</div>
5752
5753<div class="doc_text">
5754
5755<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5756<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5757 floating point or vector of floating point type. Not all targets support all
5758 types however.</p>
5759
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5760<pre>
5761 declare float @llvm.cos.f32(float %Val)
5762 declare double @llvm.cos.f64(double %Val)
5763 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5764 declare fp128 @llvm.cos.f128(fp128 %Val)
5765 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5766</pre>
5767
5768<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5769<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5770
5771<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5772<p>The argument and return value are floating point numbers of the same
5773 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5774
5775<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5776<p>This function returns the cosine of the specified operand, returning the same
5777 values as the libm <tt>cos</tt> functions would, and handles error conditions
5778 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5779
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5780</div>
5781
5782<!-- _______________________________________________________________________ -->
5783<div class="doc_subsubsection">
5784 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5785</div>
5786
5787<div class="doc_text">
5788
5789<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5790<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5791 floating point or vector of floating point type. Not all targets support all
5792 types however.</p>
5793
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5794<pre>
5795 declare float @llvm.pow.f32(float %Val, float %Power)
5796 declare double @llvm.pow.f64(double %Val, double %Power)
5797 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5798 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5799 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5800</pre>
5801
5802<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5803<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5804 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5805
5806<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5807<p>The second argument is a floating point power, and the first is a value to
5808 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5809
5810<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5811<p>This function returns the first value raised to the second power, returning
5812 the same values as the libm <tt>pow</tt> functions would, and handles error
5813 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5814
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5815</div>
5816
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5817<!-- ======================================================================= -->
5818<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5819 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5820</div>
5821
5822<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5823
5824<p>LLVM provides intrinsics for a few important bit manipulation operations.
5825 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5826
5827</div>
5828
5829<!-- _______________________________________________________________________ -->
5830<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5831 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5832</div>
5833
5834<div class="doc_text">
5835
5836<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5837<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5838 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
5839
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5840<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5841 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5842 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5843 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5844</pre>
5845
5846<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5847<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
5848 values with an even number of bytes (positive multiple of 16 bits). These
5849 are useful for performing operations on data that is not in the target's
5850 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5851
5852<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5853<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
5854 and low byte of the input i16 swapped. Similarly,
5855 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
5856 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
5857 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
5858 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
5859 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
5860 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5861
5862</div>
5863
5864<!-- _______________________________________________________________________ -->
5865<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5866 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5867</div>
5868
5869<div class="doc_text">
5870
5871<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5872<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5873 width. Not all targets support all bit widths however.</p>
5874
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5875<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5876 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5877 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5878 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5879 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5880 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5881</pre>
5882
5883<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5884<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
5885 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5886
5887<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5888<p>The only argument is the value to be counted. The argument may be of any
5889 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5890
5891<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5892<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5893
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5894</div>
5895
5896<!-- _______________________________________________________________________ -->
5897<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5898 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5899</div>
5900
5901<div class="doc_text">
5902
5903<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5904<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
5905 integer bit width. Not all targets support all bit widths however.</p>
5906
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5907<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5908 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5909 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5910 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5911 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5912 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5913</pre>
5914
5915<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5916<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5917 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5918
5919<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5920<p>The only argument is the value to be counted. The argument may be of any
5921 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5922
5923<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5924<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
5925 zeros in a variable. If the src == 0 then the result is the size in bits of
5926 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5927
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5928</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5929
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5930<!-- _______________________________________________________________________ -->
5931<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5932 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5933</div>
5934
5935<div class="doc_text">
5936
5937<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5938<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
5939 integer bit width. Not all targets support all bit widths however.</p>
5940
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5941<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5942 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5943 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5944 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5945 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5946 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5947</pre>
5948
5949<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5950<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5951 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5952
5953<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5954<p>The only argument is the value to be counted. The argument may be of any
5955 integer type. The return type must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5956
5957<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5958<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
5959 zeros in a variable. If the src == 0 then the result is the size in bits of
5960 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5961
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5962</div>
5963
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]5964<!-- ======================================================================= -->
5965<div class="doc_subsection">
5966 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
5967</div>
5968
5969<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5970
5971<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]5972
5973</div>
5974
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5975<!-- _______________________________________________________________________ -->
5976<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]5977 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5978</div>
5979
5980<div class="doc_text">
5981
5982<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5983<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5984 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5985
5986<pre>
5987 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
5988 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5989 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
5990</pre>
5991
5992<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5993<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5994 a signed addition of the two arguments, and indicate whether an overflow
5995 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5996
5997<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5998<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5999 be of integer types of any bit width, but they must have the same bit
6000 width. The second element of the result structure must be of
6001 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6002 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6003
6004<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6005<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6006 a signed addition of the two variables. They return a structure &mdash; the
6007 first element of which is the signed summation, and the second element of
6008 which is a bit specifying if the signed summation resulted in an
6009 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6010
6011<h5>Examples:</h5>
6012<pre>
6013 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6014 %sum = extractvalue {i32, i1} %res, 0
6015 %obit = extractvalue {i32, i1} %res, 1
6016 br i1 %obit, label %overflow, label %normal
6017</pre>
6018
6019</div>
6020
6021<!-- _______________________________________________________________________ -->
6022<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6023 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6024</div>
6025
6026<div class="doc_text">
6027
6028<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6029<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6030 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6031
6032<pre>
6033 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6034 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6035 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6036</pre>
6037
6038<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6039<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6040 an unsigned addition of the two arguments, and indicate whether a carry
6041 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6042
6043<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6044<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6045 be of integer types of any bit width, but they must have the same bit
6046 width. The second element of the result structure must be of
6047 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6048 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6049
6050<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6051<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6052 an unsigned addition of the two arguments. They return a structure &mdash;
6053 the first element of which is the sum, and the second element of which is a
6054 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6055
6056<h5>Examples:</h5>
6057<pre>
6058 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6059 %sum = extractvalue {i32, i1} %res, 0
6060 %obit = extractvalue {i32, i1} %res, 1
6061 br i1 %obit, label %carry, label %normal
6062</pre>
6063
6064</div>
6065
6066<!-- _______________________________________________________________________ -->
6067<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6068 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6069</div>
6070
6071<div class="doc_text">
6072
6073<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6074<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6075 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6076
6077<pre>
6078 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6079 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6080 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6081</pre>
6082
6083<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6084<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6085 a signed subtraction of the two arguments, and indicate whether an overflow
6086 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6087
6088<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6089<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6090 be of integer types of any bit width, but they must have the same bit
6091 width. The second element of the result structure must be of
6092 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6093 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6094
6095<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6096<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6097 a signed subtraction of the two arguments. They return a structure &mdash;
6098 the first element of which is the subtraction, and the second element of
6099 which is a bit specifying if the signed subtraction resulted in an
6100 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6101
6102<h5>Examples:</h5>
6103<pre>
6104 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6105 %sum = extractvalue {i32, i1} %res, 0
6106 %obit = extractvalue {i32, i1} %res, 1
6107 br i1 %obit, label %overflow, label %normal
6108</pre>
6109
6110</div>
6111
6112<!-- _______________________________________________________________________ -->
6113<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6114 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6115</div>
6116
6117<div class="doc_text">
6118
6119<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6120<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6121 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6122
6123<pre>
6124 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6125 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6126 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6127</pre>
6128
6129<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6130<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6131 an unsigned subtraction of the two arguments, and indicate whether an
6132 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6133
6134<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6135<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6136 be of integer types of any bit width, but they must have the same bit
6137 width. The second element of the result structure must be of
6138 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6139 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6140
6141<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6142<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6143 an unsigned subtraction of the two arguments. They return a structure &mdash;
6144 the first element of which is the subtraction, and the second element of
6145 which is a bit specifying if the unsigned subtraction resulted in an
6146 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6147
6148<h5>Examples:</h5>
6149<pre>
6150 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6151 %sum = extractvalue {i32, i1} %res, 0
6152 %obit = extractvalue {i32, i1} %res, 1
6153 br i1 %obit, label %overflow, label %normal
6154</pre>
6155
6156</div>
6157
6158<!-- _______________________________________________________________________ -->
6159<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6160 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6161</div>
6162
6163<div class="doc_text">
6164
6165<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6166<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6167 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6168
6169<pre>
6170 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6171 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6172 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6173</pre>
6174
6175<h5>Overview:</h5>
6176
6177<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6178 a signed multiplication of the two arguments, and indicate whether an
6179 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6180
6181<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6182<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6183 be of integer types of any bit width, but they must have the same bit
6184 width. The second element of the result structure must be of
6185 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6186 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6187
6188<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6189<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6190 a signed multiplication of the two arguments. They return a structure &mdash;
6191 the first element of which is the multiplication, and the second element of
6192 which is a bit specifying if the signed multiplication resulted in an
6193 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6194
6195<h5>Examples:</h5>
6196<pre>
6197 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6198 %sum = extractvalue {i32, i1} %res, 0
6199 %obit = extractvalue {i32, i1} %res, 1
6200 br i1 %obit, label %overflow, label %normal
6201</pre>
6202
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]6203</div>
6204
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6205<!-- _______________________________________________________________________ -->
6206<div class="doc_subsubsection">
6207 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6208</div>
6209
6210<div class="doc_text">
6211
6212<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6213<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6214 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6215
6216<pre>
6217 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6218 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6219 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6220</pre>
6221
6222<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6223<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6224 a unsigned multiplication of the two arguments, and indicate whether an
6225 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6226
6227<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6228<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6229 be of integer types of any bit width, but they must have the same bit
6230 width. The second element of the result structure must be of
6231 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6232 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6233
6234<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6235<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6236 an unsigned multiplication of the two arguments. They return a structure
6237 &mdash; the first element of which is the multiplication, and the second
6238 element of which is a bit specifying if the unsigned multiplication resulted
6239 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6240
6241<h5>Examples:</h5>
6242<pre>
6243 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6244 %sum = extractvalue {i32, i1} %res, 0
6245 %obit = extractvalue {i32, i1} %res, 1
6246 br i1 %obit, label %overflow, label %normal
6247</pre>
6248
6249</div>
6250
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6251<!-- ======================================================================= -->
6252<div class="doc_subsection">
6253 <a name="int_debugger">Debugger Intrinsics</a>
6254</div>
6255
6256<div class="doc_text">
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6257
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6258<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6259 prefix), are described in
6260 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6261 Level Debugging</a> document.</p>
6262
6263</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6264
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6265<!-- ======================================================================= -->
6266<div class="doc_subsection">
6267 <a name="int_eh">Exception Handling Intrinsics</a>
6268</div>
6269
6270<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6271
6272<p>The LLVM exception handling intrinsics (which all start with
6273 <tt>llvm.eh.</tt> prefix), are described in
6274 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6275 Handling</a> document.</p>
6276
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6277</div>
6278
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6279<!-- ======================================================================= -->
6280<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6281 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6282</div>
6283
6284<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6285
6286<p>This intrinsic makes it possible to excise one parameter, marked with
6287 the <tt>nest</tt> attribute, from a function. The result is a callable
6288 function pointer lacking the nest parameter - the caller does not need to
6289 provide a value for it. Instead, the value to use is stored in advance in a
6290 "trampoline", a block of memory usually allocated on the stack, which also
6291 contains code to splice the nest value into the argument list. This is used
6292 to implement the GCC nested function address extension.</p>
6293
6294<p>For example, if the function is
6295 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6296 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6297 follows:</p>
6298
6299<div class="doc_code">
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6300<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6301 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6302 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6303 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6304 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6305</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6306</div>
6307
6308<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6309 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6310
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6311</div>
6312
6313<!-- _______________________________________________________________________ -->
6314<div class="doc_subsubsection">
6315 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6316</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6317
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6318<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6319
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6320<h5>Syntax:</h5>
6321<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6322 declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6323</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6324
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6325<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6326<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6327 function pointer suitable for executing it.</p>
6328
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6329<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6330<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6331 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6332 sufficiently aligned block of memory; this memory is written to by the
6333 intrinsic. Note that the size and the alignment are target-specific - LLVM
6334 currently provides no portable way of determining them, so a front-end that
6335 generates this intrinsic needs to have some target-specific knowledge.
6336 The <tt>func</tt> argument must hold a function bitcast to
6337 an <tt>i8*</tt>.</p>
6338
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6339<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6340<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6341 dependent code, turning it into a function. A pointer to this function is
6342 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6343 function pointer type</a> before being called. The new function's signature
6344 is the same as that of <tt>func</tt> with any arguments marked with
6345 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6346 is allowed, and it must be of pointer type. Calling the new function is
6347 equivalent to calling <tt>func</tt> with the same argument list, but
6348 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6349 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6350 by <tt>tramp</tt> is modified, then the effect of any later call to the
6351 returned function pointer is undefined.</p>
6352
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6353</div>
6354
6355<!-- ======================================================================= -->
6356<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6357 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6358</div>
6359
6360<div class="doc_text">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6361
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6362<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6363 hardware constructs for atomic operations and memory synchronization. This
6364 provides an interface to the hardware, not an interface to the programmer. It
6365 is aimed at a low enough level to allow any programming models or APIs
6366 (Application Programming Interfaces) which need atomic behaviors to map
6367 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6368 hardware provides a "universal IR" for source languages, it also provides a
6369 starting point for developing a "universal" atomic operation and
6370 synchronization IR.</p>
6371
6372<p>These do <em>not</em> form an API such as high-level threading libraries,
6373 software transaction memory systems, atomic primitives, and intrinsic
6374 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6375 application libraries. The hardware interface provided by LLVM should allow
6376 a clean implementation of all of these APIs and parallel programming models.
6377 No one model or paradigm should be selected above others unless the hardware
6378 itself ubiquitously does so.</p>
6379
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6380</div>
6381
6382<!-- _______________________________________________________________________ -->
6383<div class="doc_subsubsection">
6384 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6385</div>
6386<div class="doc_text">
6387<h5>Syntax:</h5>
6388<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6389 declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;, i1 &lt;device&gt; )
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6390</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6391
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6392<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6393<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6394 specific pairs of memory access types.</p>
6395
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6396<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6397<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6398 The first four arguments enables a specific barrier as listed below. The
6399 fith argument specifies that the barrier applies to io or device or uncached
6400 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6401
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6402<ul>
6403 <li><tt>ll</tt>: load-load barrier</li>
6404 <li><tt>ls</tt>: load-store barrier</li>
6405 <li><tt>sl</tt>: store-load barrier</li>
6406 <li><tt>ss</tt>: store-store barrier</li>
6407 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6408</ul>
6409
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6410<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6411<p>This intrinsic causes the system to enforce some ordering constraints upon
6412 the loads and stores of the program. This barrier does not
6413 indicate <em>when</em> any events will occur, it only enforces
6414 an <em>order</em> in which they occur. For any of the specified pairs of load
6415 and store operations (f.ex. load-load, or store-load), all of the first
6416 operations preceding the barrier will complete before any of the second
6417 operations succeeding the barrier begin. Specifically the semantics for each
6418 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6419
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6420<ul>
6421 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6422 after the barrier begins.</li>
6423 <li><tt>ls</tt>: All loads before the barrier must complete before any
6424 store after the barrier begins.</li>
6425 <li><tt>ss</tt>: All stores before the barrier must complete before any
6426 store after the barrier begins.</li>
6427 <li><tt>sl</tt>: All stores before the barrier must complete before any
6428 load after the barrier begins.</li>
6429</ul>
6430
6431<p>These semantics are applied with a logical "and" behavior when more than one
6432 is enabled in a single memory barrier intrinsic.</p>
6433
6434<p>Backends may implement stronger barriers than those requested when they do
6435 not support as fine grained a barrier as requested. Some architectures do
6436 not need all types of barriers and on such architectures, these become
6437 noops.</p>
6438
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6439<h5>Example:</h5>
6440<pre>
6441%ptr = malloc i32
6442 store i32 4, %ptr
6443
6444%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6445 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6446 <i>; guarantee the above finishes</i>
6447 store i32 8, %ptr <i>; before this begins</i>
6448</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6449
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6450</div>
6451
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6452<!-- _______________________________________________________________________ -->
6453<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6454 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6455</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6456
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6457<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6458
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6459<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6460<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6461 any integer bit width and for different address spaces. Not all targets
6462 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6463
6464<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6465 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6466 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6467 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6468 declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6469</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6470
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6471<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6472<p>This loads a value in memory and compares it to a given value. If they are
6473 equal, it stores a new value into the memory.</p>
6474
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6475<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6476<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6477 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6478 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6479 this integer type. While any bit width integer may be used, targets may only
6480 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6481
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6482<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6483<p>This entire intrinsic must be executed atomically. It first loads the value
6484 in memory pointed to by <tt>ptr</tt> and compares it with the
6485 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6486 memory. The loaded value is yielded in all cases. This provides the
6487 equivalent of an atomic compare-and-swap operation within the SSA
6488 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6489
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6490<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6491<pre>
6492%ptr = malloc i32
6493 store i32 4, %ptr
6494
6495%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6496%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6497 <i>; yields {i32}:result1 = 4</i>
6498%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6499%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6500
6501%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6502%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6503 <i>; yields {i32}:result2 = 8</i>
6504%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6505
6506%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6507</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6508
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6509</div>
6510
6511<!-- _______________________________________________________________________ -->
6512<div class="doc_subsubsection">
6513 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6514</div>
6515<div class="doc_text">
6516<h5>Syntax:</h5>
6517
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6518<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6519 integer bit width. Not all targets support all bit widths however.</p>
6520
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6521<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6522 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6523 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6524 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6525 declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6526</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6527
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6528<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6529<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6530 the value from memory. It then stores the value in <tt>val</tt> in the memory
6531 at <tt>ptr</tt>.</p>
6532
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6533<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6534<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
6535 the <tt>val</tt> argument and the result must be integers of the same bit
6536 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6537 integer type. The targets may only lower integer representations they
6538 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6539
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6540<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6541<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6542 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6543 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6544
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6545<h5>Examples:</h5>
6546<pre>
6547%ptr = malloc i32
6548 store i32 4, %ptr
6549
6550%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6551%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6552 <i>; yields {i32}:result1 = 4</i>
6553%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6554%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6555
6556%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6557%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6558 <i>; yields {i32}:result2 = 8</i>
6559
6560%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6561%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6562</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6563
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6564</div>
6565
6566<!-- _______________________________________________________________________ -->
6567<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6568 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6569
6570</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6571
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6572<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6573
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6574<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6575<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
6576 any integer bit width. Not all targets support all bit widths however.</p>
6577
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6578<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6579 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6580 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6581 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6582 declare i64 @llvm.atomic.load.add.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6583</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6584
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6585<h5>Overview:</h5>
6586<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
6587 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6588
6589<h5>Arguments:</h5>
6590<p>The intrinsic takes two arguments, the first a pointer to an integer value
6591 and the second an integer value. The result is also an integer value. These
6592 integer types can have any bit width, but they must all have the same bit
6593 width. The targets may only lower integer representations they support.</p>
6594
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6595<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6596<p>This intrinsic does a series of operations atomically. It first loads the
6597 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6598 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6599
6600<h5>Examples:</h5>
6601<pre>
6602%ptr = malloc i32
6603 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6604%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6605 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6606%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6607 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6608%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6609 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6610%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6611</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6612
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6613</div>
6614
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6615<!-- _______________________________________________________________________ -->
6616<div class="doc_subsubsection">
6617 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6618
6619</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6620
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6621<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6622
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6623<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6624<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
6625 any integer bit width and for different address spaces. Not all targets
6626 support all bit widths however.</p>
6627
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6628<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6629 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6630 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6631 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6632 declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6633</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6634
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6635<h5>Overview:</h5>
6636<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6637 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6638
6639<h5>Arguments:</h5>
6640<p>The intrinsic takes two arguments, the first a pointer to an integer value
6641 and the second an integer value. The result is also an integer value. These
6642 integer types can have any bit width, but they must all have the same bit
6643 width. The targets may only lower integer representations they support.</p>
6644
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6645<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6646<p>This intrinsic does a series of operations atomically. It first loads the
6647 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6648 result to <tt>ptr</tt>. It yields the original value stored
6649 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6650
6651<h5>Examples:</h5>
6652<pre>
6653%ptr = malloc i32
6654 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6655%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6656 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6657%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6658 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6659%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6660 <i>; yields {i32}:result3 = 2</i>
6661%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6662</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6663
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6664</div>
6665
6666<!-- _______________________________________________________________________ -->
6667<div class="doc_subsubsection">
6668 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6669 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6670 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6671 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6672</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6673
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6674<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6675
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6676<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6677<p>These are overloaded intrinsics. You can
6678 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
6679 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
6680 bit width and for different address spaces. Not all targets support all bit
6681 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6682
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6683<pre>
6684 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6685 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6686 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6687 declare i64 @llvm.atomic.load.and.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6688</pre>
6689
6690<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6691 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6692 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6693 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6694 declare i64 @llvm.atomic.load.or.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6695</pre>
6696
6697<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6698 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6699 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6700 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6701 declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6702</pre>
6703
6704<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6705 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6706 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6707 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6708 declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6709</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6710
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6711<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6712<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6713 the value stored in memory at <tt>ptr</tt>. It yields the original value
6714 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6715
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6716<h5>Arguments:</h5>
6717<p>These intrinsics take two arguments, the first a pointer to an integer value
6718 and the second an integer value. The result is also an integer value. These
6719 integer types can have any bit width, but they must all have the same bit
6720 width. The targets may only lower integer representations they support.</p>
6721
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6722<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6723<p>These intrinsics does a series of operations atomically. They first load the
6724 value stored at <tt>ptr</tt>. They then do the bitwise
6725 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
6726 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6727
6728<h5>Examples:</h5>
6729<pre>
6730%ptr = malloc i32
6731 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6732%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6733 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6734%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6735 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6736%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6737 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6738%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6739 <i>; yields {i32}:result3 = FF</i>
6740%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6741</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6742
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6743</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6744
6745<!-- _______________________________________________________________________ -->
6746<div class="doc_subsubsection">
6747 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6748 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6749 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6750 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6751</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6752
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6753<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6754
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6755<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6756<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6757 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
6758 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6759 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6760
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6761<pre>
6762 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6763 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6764 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6765 declare i64 @llvm.atomic.load.max.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6766</pre>
6767
6768<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6769 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6770 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6771 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6772 declare i64 @llvm.atomic.load.min.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6773</pre>
6774
6775<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6776 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6777 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6778 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6779 declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6780</pre>
6781
6782<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6783 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6784 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6785 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6786 declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6787</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6788
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6789<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6790<p>These intrinsics takes the signed or unsigned minimum or maximum of
6791 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6792 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6793
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6794<h5>Arguments:</h5>
6795<p>These intrinsics take two arguments, the first a pointer to an integer value
6796 and the second an integer value. The result is also an integer value. These
6797 integer types can have any bit width, but they must all have the same bit
6798 width. The targets may only lower integer representations they support.</p>
6799
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6800<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6801<p>These intrinsics does a series of operations atomically. They first load the
6802 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
6803 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
6804 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6805
6806<h5>Examples:</h5>
6807<pre>
6808%ptr = malloc i32
6809 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6810%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6811 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6812%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6813 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6814%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6815 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6816%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6817 <i>; yields {i32}:result3 = 8</i>
6818%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6819</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6820
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6821</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6822
6823<!-- ======================================================================= -->
6824<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6825 <a name="int_general">General Intrinsics</a>
6826</div>
6827
6828<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6829
6830<p>This class of intrinsics is designed to be generic and has no specific
6831 purpose.</p>
6832
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6833</div>
6834
6835<!-- _______________________________________________________________________ -->
6836<div class="doc_subsubsection">
6837 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6838</div>
6839
6840<div class="doc_text">
6841
6842<h5>Syntax:</h5>
6843<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6844 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6845</pre>
6846
6847<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6848<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6849
6850<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6851<p>The first argument is a pointer to a value, the second is a pointer to a
6852 global string, the third is a pointer to a global string which is the source
6853 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6854
6855<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6856<p>This intrinsic allows annotation of local variables with arbitrary strings.
6857 This can be useful for special purpose optimizations that want to look for
6858 these annotations. These have no other defined use, they are ignored by code
6859 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6860
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6861</div>
6862
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6863<!-- _______________________________________________________________________ -->
6864<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]6865 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6866</div>
6867
6868<div class="doc_text">
6869
6870<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6871<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6872 any integer bit width.</p>
6873
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6874<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]6875 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6876 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6877 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6878 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6879 declare i256 @llvm.annotation.i256(i256 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6880</pre>
6881
6882<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6883<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6884
6885<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6886<p>The first argument is an integer value (result of some expression), the
6887 second is a pointer to a global string, the third is a pointer to a global
6888 string which is the source file name, and the last argument is the line
6889 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6890
6891<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6892<p>This intrinsic allows annotations to be put on arbitrary expressions with
6893 arbitrary strings. This can be useful for special purpose optimizations that
6894 want to look for these annotations. These have no other defined use, they
6895 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6896
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6897</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6898
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6899<!-- _______________________________________________________________________ -->
6900<div class="doc_subsubsection">
6901 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6902</div>
6903
6904<div class="doc_text">
6905
6906<h5>Syntax:</h5>
6907<pre>
6908 declare void @llvm.trap()
6909</pre>
6910
6911<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6912<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6913
6914<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6915<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6916
6917<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6918<p>This intrinsics is lowered to the target dependent trap instruction. If the
6919 target does not have a trap instruction, this intrinsic will be lowered to
6920 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6921
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6922</div>
6923
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6924<!-- _______________________________________________________________________ -->
6925<div class="doc_subsubsection">
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]6926 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6927</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6928
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6929<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6930
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6931<h5>Syntax:</h5>
6932<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6933 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6934</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6935
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6936<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6937<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
6938 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
6939 ensure that it is placed on the stack before local variables.</p>
6940
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6941<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6942<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
6943 arguments. The first argument is the value loaded from the stack
6944 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
6945 that has enough space to hold the value of the guard.</p>
6946
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6947<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6948<p>This intrinsic causes the prologue/epilogue inserter to force the position of
6949 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6950 stack. This is to ensure that if a local variable on the stack is
6951 overwritten, it will destroy the value of the guard. When the function exits,
6952 the guard on the stack is checked against the original guard. If they're
6953 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
6954 function.</p>
6955
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6956</div>
6957
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6958<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6959<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6960<address>
6961 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]6962 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6963 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]6964 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6965
6966 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]6967 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6968 Last modified: $Date$
6969</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]6970
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6971</body>
6972</html>