Gitiles
Code Review Sign In
gerrit-public.fairphone.software / toolchain / llvm-project / c7c346fd13a4148bda651a5be382ae605573c97b / . / llvm / docs / LangRef.html
blob: 6e77b4ac90b628754920070ddf2fc78976280c67 [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">
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]8 <meta name="description"
Reid Spencercb84e432004-08-26 20:44:00 +0000[diff] [blame]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
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]15<h1>LLVM Language Reference Manual</h1>
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>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]27 <li><a href="#linkage_linker_private_weak">'<tt>linker_private_weak</tt>' Linkage</a></li>
Bill Wendling578ee402010-08-20 22:05:50 +0000[diff] [blame]28 <li><a href="#linkage_linker_private_weak_def_auto">'<tt>linker_private_weak_def_auto</tt>' Linkage</a></li>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]29 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
30 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
31 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
32 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
33 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
34 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
35 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
Chris Lattner80d73c72009-10-10 18:26:06 +0000[diff] [blame]36 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]37 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
38 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
39 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
40 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]41 </ol>
42 </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]43 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]44 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]45 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]46 <li><a href="#functionstructure">Functions</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]47 <li><a href="#aliasstructure">Aliases</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]48 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]49 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]50 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]51 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]52 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]53 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]54 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]55 <li><a href="#volatile">Volatile Memory Accesses</a></li>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]56 <li><a href="#memmodel">Memory Model for Concurrent Operations</a></li>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]57 <li><a href="#ordering">Atomic Memory Ordering Constraints</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]58 </ol>
59 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]60 <li><a href="#typesystem">Type System</a>
61 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]62 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]63 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]64 <ol>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]65 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]66 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]67 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]68 <li><a href="#t_void">Void Type</a></li>
69 <li><a href="#t_label">Label Type</a></li>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]70 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]71 </ol>
72 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]73 <li><a href="#t_derived">Derived Types</a>
74 <ol>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]75 <li><a href="#t_aggregate">Aggregate Types</a>
76 <ol>
77 <li><a href="#t_array">Array Type</a></li>
78 <li><a href="#t_struct">Structure Type</a></li>
Chris Lattner2a843822011-07-23 19:59:08 +0000[diff] [blame]79 <li><a href="#t_opaque">Opaque Structure Types</a></li>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]80 <li><a href="#t_vector">Vector Type</a></li>
81 </ol>
82 </li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]83 <li><a href="#t_function">Function Type</a></li>
84 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]85 </ol>
86 </li>
87 </ol>
88 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]89 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]90 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]91 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]92 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]93 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
94 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]95 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]96 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]97 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]98 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]99 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]100 <li><a href="#othervalues">Other Values</a>
101 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]102 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]103 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]104 </ol>
105 </li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]106 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
107 <ol>
108 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]109 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
110 Global Variable</a></li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]111 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
112 Global Variable</a></li>
113 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
114 Global Variable</a></li>
115 </ol>
116 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]117 <li><a href="#instref">Instruction Reference</a>
118 <ol>
119 <li><a href="#terminators">Terminator Instructions</a>
120 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]121 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
122 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]123 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]124 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]125 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]126 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Bill Wendlingf891bf82011-07-31 06:30:59 +0000[diff] [blame]127 <li><a href="#i_resume">'<tt>resume</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]128 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]129 </ol>
130 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]131 <li><a href="#binaryops">Binary Operations</a>
132 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]133 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]134 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]135 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]136 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]137 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]138 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]139 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
140 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
141 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]142 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
143 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
144 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]145 </ol>
146 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]147 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
148 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]149 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
150 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
151 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]152 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]153 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]154 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]155 </ol>
156 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]157 <li><a href="#vectorops">Vector Operations</a>
158 <ol>
159 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
160 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
161 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]162 </ol>
163 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]164 <li><a href="#aggregateops">Aggregate Operations</a>
165 <ol>
166 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
167 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
168 </ol>
169 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]170 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]171 <ol>
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]172 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
173 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
174 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
175 <li><a href="#i_fence">'<tt>fence</tt>' Instruction</a></li>
176 <li><a href="#i_cmpxchg">'<tt>cmpxchg</tt>' Instruction</a></li>
177 <li><a href="#i_atomicrmw">'<tt>atomicrmw</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]178 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]179 </ol>
180 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]181 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]182 <ol>
183 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
184 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
185 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
186 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
187 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]188 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
189 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
190 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
191 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]192 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
193 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]194 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]195 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]196 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]197 <li><a href="#otherops">Other Operations</a>
198 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]199 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
200 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]201 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]202 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]203 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]204 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]205 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]206 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]207 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]208 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]209 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]210 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]211 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
212 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]213 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
214 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
215 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]216 </ol>
217 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]218 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
219 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]220 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
221 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
222 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]223 </ol>
224 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]225 <li><a href="#int_codegen">Code Generator Intrinsics</a>
226 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]227 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
228 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
229 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
230 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
231 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
232 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohmane58f7b32010-05-26 21:56:15 +0000[diff] [blame]233 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]234 </ol>
235 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]236 <li><a href="#int_libc">Standard C Library Intrinsics</a>
237 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]238 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
239 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
240 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
241 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
242 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]243 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
244 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
245 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohmane635c522011-05-27 00:36:31 +0000[diff] [blame]246 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
247 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]248 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]249 </ol>
250 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]251 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]252 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]253 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]254 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
255 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
256 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]257 </ol>
258 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]259 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
260 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]261 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
262 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
263 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
264 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
265 <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]266 <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]267 </ol>
268 </li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]269 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
270 <ol>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]271 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
272 <li><a href="#int_convert_from_fp16">'<tt>llvm.convert.from.fp16</tt>' Intrinsic</a></li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]273 </ol>
274 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]275 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]276 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]277 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]278 <ol>
279 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]280 </ol>
281 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]282 <li><a href="#int_atomics">Atomic intrinsics</a>
283 <ol>
284 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
285 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
286 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
287 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
288 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
289 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
290 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
291 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
292 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
293 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
294 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
295 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
296 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
297 </ol>
298 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]299 <li><a href="#int_memorymarkers">Memory Use Markers</a>
300 <ol>
301 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
302 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
303 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
304 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
305 </ol>
306 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]307 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]308 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]309 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]310 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]311 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]312 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]313 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]314 '<tt>llvm.trap</tt>' Intrinsic</a></li>
315 <li><a href="#int_stackprotector">
316 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]317 <li><a href="#int_objectsize">
318 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]319 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]320 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]321 </ol>
322 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]323</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]324
325<div class="doc_author">
326 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
327 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]328</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]329
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]330<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]331<h2><a name="abstract">Abstract</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]332<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]333
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]334<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]335
336<p>This document is a reference manual for the LLVM assembly language. LLVM is
337 a Static Single Assignment (SSA) based representation that provides type
338 safety, low-level operations, flexibility, and the capability of representing
339 'all' high-level languages cleanly. It is the common code representation
340 used throughout all phases of the LLVM compilation strategy.</p>
341
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]342</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]343
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]344<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]345<h2><a name="introduction">Introduction</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]346<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]347
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]348<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]349
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]350<p>The LLVM code representation is designed to be used in three different forms:
351 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
352 for fast loading by a Just-In-Time compiler), and as a human readable
353 assembly language representation. This allows LLVM to provide a powerful
354 intermediate representation for efficient compiler transformations and
355 analysis, while providing a natural means to debug and visualize the
356 transformations. The three different forms of LLVM are all equivalent. This
357 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]358
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]359<p>The LLVM representation aims to be light-weight and low-level while being
360 expressive, typed, and extensible at the same time. It aims to be a
361 "universal IR" of sorts, by being at a low enough level that high-level ideas
362 may be cleanly mapped to it (similar to how microprocessors are "universal
363 IR's", allowing many source languages to be mapped to them). By providing
364 type information, LLVM can be used as the target of optimizations: for
365 example, through pointer analysis, it can be proven that a C automatic
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]366 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]367 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]368
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]369<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]370<h4>
371 <a name="wellformed">Well-Formedness</a>
372</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]373
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]374<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]375
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]376<p>It is important to note that this document describes 'well formed' LLVM
377 assembly language. There is a difference between what the parser accepts and
378 what is considered 'well formed'. For example, the following instruction is
379 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]380
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]381<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]382%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]383</pre>
384
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]385<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
386 LLVM infrastructure provides a verification pass that may be used to verify
387 that an LLVM module is well formed. This pass is automatically run by the
388 parser after parsing input assembly and by the optimizer before it outputs
389 bitcode. The violations pointed out by the verifier pass indicate bugs in
390 transformation passes or input to the parser.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]391
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]392</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]393
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]394</div>
395
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]396<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]397
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]398<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]399<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]400<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]401
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]402<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]403
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]404<p>LLVM identifiers come in two basic types: global and local. Global
405 identifiers (functions, global variables) begin with the <tt>'@'</tt>
406 character. Local identifiers (register names, types) begin with
407 the <tt>'%'</tt> character. Additionally, there are three different formats
408 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]409
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]410<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]411 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]412 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
413 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
414 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
415 other characters in their names can be surrounded with quotes. Special
416 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
417 ASCII code for the character in hexadecimal. In this way, any character
418 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]419
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]420 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]421 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]422
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]423 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]424 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]425</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]426
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]427<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]428 don't need to worry about name clashes with reserved words, and the set of
429 reserved words may be expanded in the future without penalty. Additionally,
430 unnamed identifiers allow a compiler to quickly come up with a temporary
431 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]432
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]433<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]434 languages. There are keywords for different opcodes
435 ('<tt><a href="#i_add">add</a></tt>',
436 '<tt><a href="#i_bitcast">bitcast</a></tt>',
437 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
438 ('<tt><a href="#t_void">void</a></tt>',
439 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
440 reserved words cannot conflict with variable names, because none of them
441 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]442
443<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]444 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]445
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]446<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]447
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]448<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]449%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]450</pre>
451
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]452<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]453
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]454<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]455%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]456</pre>
457
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]458<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]459
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]460<pre class="doc_code">
Gabor Greifbd0328f2009-10-28 13:05:07 +0000[diff] [blame]461%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
462%1 = <a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]463%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]464</pre>
465
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]466<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
467 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]468
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]469<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]470 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]471 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]472
473 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]474 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]475
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]476 <li>Unnamed temporaries are numbered sequentially</li>
477</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]478
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]479<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]480 demonstrating instructions, we will follow an instruction with a comment that
481 defines the type and name of value produced. Comments are shown in italic
482 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]483
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]484</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]485
486<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]487<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]488<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]489<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]490<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]491<h3>
492 <a name="modulestructure">Module Structure</a>
493</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]494
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]495<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]496
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]497<p>LLVM programs are composed of "Module"s, each of which is a translation unit
498 of the input programs. Each module consists of functions, global variables,
499 and symbol table entries. Modules may be combined together with the LLVM
500 linker, which merges function (and global variable) definitions, resolves
501 forward declarations, and merges symbol table entries. Here is an example of
502 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]503
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]504<pre class="doc_code">
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]505<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckyfea7ddc2011-01-29 01:09:53 +0000[diff] [blame]506<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a>&nbsp;<a href="#globalvars">constant</a>&nbsp;<a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]507
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]508<i>; External declaration of the puts function</i>&nbsp;
509<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]510
511<i>; Definition of main function</i>
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]512define i32 @main() { <i>; i32()* </i>&nbsp;
513 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
514 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8*</i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]515
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]516 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
517 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
518 <a href="#i_ret">ret</a> i32 0&nbsp;
519}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]520
521<i>; Named metadata</i>
522!1 = metadata !{i32 41}
523!foo = !{!1, null}
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]524</pre>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]525
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]526<p>This example is made up of a <a href="#globalvars">global variable</a> named
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]527 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]528 a <a href="#functionstructure">function definition</a> for
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]529 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
530 "<tt>foo"</tt>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]531
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]532<p>In general, a module is made up of a list of global values, where both
533 functions and global variables are global values. Global values are
534 represented by a pointer to a memory location (in this case, a pointer to an
535 array of char, and a pointer to a function), and have one of the
536 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]537
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]538</div>
539
540<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]541<h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]542 <a name="linkage">Linkage Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]543</h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]544
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]545<div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]546
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]547<p>All Global Variables and Functions have one of the following types of
548 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]549
550<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]551 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]552 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
553 by objects in the current module. In particular, linking code into a
554 module with an private global value may cause the private to be renamed as
555 necessary to avoid collisions. Because the symbol is private to the
556 module, all references can be updated. This doesn't show up in any symbol
557 table in the object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]558
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]559 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]560 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
561 assembler and evaluated by the linker. Unlike normal strong symbols, they
562 are removed by the linker from the final linked image (executable or
563 dynamic library).</dd>
564
565 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
566 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
567 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
568 linker. The symbols are removed by the linker from the final linked image
569 (executable or dynamic library).</dd>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]570
Bill Wendling578ee402010-08-20 22:05:50 +0000[diff] [blame]571 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
572 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
573 of the object is not taken. For instance, functions that had an inline
574 definition, but the compiler decided not to inline it. Note,
575 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
576 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
577 visibility. The symbols are removed by the linker from the final linked
578 image (executable or dynamic library).</dd>
579
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]580 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling36321712010-06-29 22:34:52 +0000[diff] [blame]581 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]582 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
583 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]584
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]585 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]586 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]587 into the object file corresponding to the LLVM module. They exist to
588 allow inlining and other optimizations to take place given knowledge of
589 the definition of the global, which is known to be somewhere outside the
590 module. Globals with <tt>available_externally</tt> linkage are allowed to
591 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
592 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]593
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]594 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]595 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner0de4caa2010-01-09 19:15:14 +0000[diff] [blame]596 the same name when linkage occurs. This can be used to implement
597 some forms of inline functions, templates, or other code which must be
598 generated in each translation unit that uses it, but where the body may
599 be overridden with a more definitive definition later. Unreferenced
600 <tt>linkonce</tt> globals are allowed to be discarded. Note that
601 <tt>linkonce</tt> linkage does not actually allow the optimizer to
602 inline the body of this function into callers because it doesn't know if
603 this definition of the function is the definitive definition within the
604 program or whether it will be overridden by a stronger definition.
605 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
606 linkage.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]607
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]608 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]609 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
610 <tt>linkonce</tt> linkage, except that unreferenced globals with
611 <tt>weak</tt> linkage may not be discarded. This is used for globals that
612 are declared "weak" in C source code.</dd>
613
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]614 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]615 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
616 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
617 global scope.
618 Symbols with "<tt>common</tt>" linkage are merged in the same way as
619 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]620 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]621 must have a zero initializer, and may not be marked '<a
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]622 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
623 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]624
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]625
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]626 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]627 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]628 pointer to array type. When two global variables with appending linkage
629 are linked together, the two global arrays are appended together. This is
630 the LLVM, typesafe, equivalent of having the system linker append together
631 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]632
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]633 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]634 <dd>The semantics of this linkage follow the ELF object file model: the symbol
635 is weak until linked, if not linked, the symbol becomes null instead of
636 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]637
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]638 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
639 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]640 <dd>Some languages allow differing globals to be merged, such as two functions
641 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]642 that only equivalent globals are ever merged (the "one definition rule"
643 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]644 and <tt>weak_odr</tt> linkage types to indicate that the global will only
645 be merged with equivalent globals. These linkage types are otherwise the
646 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]647
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]648 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]649 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]650 visible, meaning that it participates in linkage and can be used to
651 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]652</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]653
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]654<p>The next two types of linkage are targeted for Microsoft Windows platform
655 only. They are designed to support importing (exporting) symbols from (to)
656 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]657
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]658<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]659 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]660 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]661 or variable via a global pointer to a pointer that is set up by the DLL
662 exporting the symbol. On Microsoft Windows targets, the pointer name is
663 formed by combining <code>__imp_</code> and the function or variable
664 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]665
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]666 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]667 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]668 pointer to a pointer in a DLL, so that it can be referenced with the
669 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
670 name is formed by combining <code>__imp_</code> and the function or
671 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]672</dl>
673
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]674<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
675 another module defined a "<tt>.LC0</tt>" variable and was linked with this
676 one, one of the two would be renamed, preventing a collision. Since
677 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
678 declarations), they are accessible outside of the current module.</p>
679
680<p>It is illegal for a function <i>declaration</i> to have any linkage type
681 other than "externally visible", <tt>dllimport</tt>
682 or <tt>extern_weak</tt>.</p>
683
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]684<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]685 or <tt>weak_odr</tt> linkages.</p>
686
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]687</div>
688
689<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]690<h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]691 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]692</h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]693
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]694<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]695
696<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]697 and <a href="#i_invoke">invokes</a> can all have an optional calling
698 convention specified for the call. The calling convention of any pair of
699 dynamic caller/callee must match, or the behavior of the program is
700 undefined. The following calling conventions are supported by LLVM, and more
701 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]702
703<dl>
704 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]705 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]706 specified) matches the target C calling conventions. This calling
707 convention supports varargs function calls and tolerates some mismatch in
708 the declared prototype and implemented declaration of the function (as
709 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]710
711 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]712 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]713 (e.g. by passing things in registers). This calling convention allows the
714 target to use whatever tricks it wants to produce fast code for the
715 target, without having to conform to an externally specified ABI
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]716 (Application Binary Interface).
717 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]718 when this or the GHC convention is used.</a> This calling convention
719 does not support varargs and requires the prototype of all callees to
720 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]721
722 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]723 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]724 as possible under the assumption that the call is not commonly executed.
725 As such, these calls often preserve all registers so that the call does
726 not break any live ranges in the caller side. This calling convention
727 does not support varargs and requires the prototype of all callees to
728 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]729
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]730 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
731 <dd>This calling convention has been implemented specifically for use by the
732 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
733 It passes everything in registers, going to extremes to achieve this by
734 disabling callee save registers. This calling convention should not be
735 used lightly but only for specific situations such as an alternative to
736 the <em>register pinning</em> performance technique often used when
737 implementing functional programming languages.At the moment only X86
738 supports this convention and it has the following limitations:
739 <ul>
740 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
741 floating point types are supported.</li>
742 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
743 6 floating point parameters.</li>
744 </ul>
745 This calling convention supports
746 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
747 requires both the caller and callee are using it.
748 </dd>
749
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]750 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]751 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]752 target-specific calling conventions to be used. Target specific calling
753 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]754</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]755
756<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]757 support Pascal conventions or any other well-known target-independent
758 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]759
760</div>
761
762<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]763<h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]764 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]765</h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]766
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]767<div>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]768
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]769<p>All Global Variables and Functions have one of the following visibility
770 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]771
772<dl>
773 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]774 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]775 that the declaration is visible to other modules and, in shared libraries,
776 means that the declared entity may be overridden. On Darwin, default
777 visibility means that the declaration is visible to other modules. Default
778 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]779
780 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]781 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]782 object if they are in the same shared object. Usually, hidden visibility
783 indicates that the symbol will not be placed into the dynamic symbol
784 table, so no other module (executable or shared library) can reference it
785 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]786
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]787 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]788 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]789 the dynamic symbol table, but that references within the defining module
790 will bind to the local symbol. That is, the symbol cannot be overridden by
791 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]792</dl>
793
794</div>
795
796<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]797<h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]798 <a name="namedtypes">Named Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]799</h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]800
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]801<div>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]802
803<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]804 it easier to read the IR and make the IR more condensed (particularly when
805 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]806
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]807<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]808%mytype = type { %mytype*, i32 }
809</pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]810
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]811<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattner249b9762010-08-17 23:26:04 +0000[diff] [blame]812 "<a href="#t_void">void</a>". Type name aliases may be used anywhere a type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]813 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]814
815<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]816 and that you can therefore specify multiple names for the same type. This
817 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
818 uses structural typing, the name is not part of the type. When printing out
819 LLVM IR, the printer will pick <em>one name</em> to render all types of a
820 particular shape. This means that if you have code where two different
821 source types end up having the same LLVM type, that the dumper will sometimes
822 print the "wrong" or unexpected type. This is an important design point and
823 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]824
825</div>
826
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]827<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]828<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]829 <a name="globalvars">Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]830</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]831
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]832<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]833
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]834<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]835 instead of run-time. Global variables may optionally be initialized, may
836 have an explicit section to be placed in, and may have an optional explicit
837 alignment specified. A variable may be defined as "thread_local", which
838 means that it will not be shared by threads (each thread will have a
839 separated copy of the variable). A variable may be defined as a global
840 "constant," which indicates that the contents of the variable
841 will <b>never</b> be modified (enabling better optimization, allowing the
842 global data to be placed in the read-only section of an executable, etc).
843 Note that variables that need runtime initialization cannot be marked
844 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]845
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]846<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
847 constant, even if the final definition of the global is not. This capability
848 can be used to enable slightly better optimization of the program, but
849 requires the language definition to guarantee that optimizations based on the
850 'constantness' are valid for the translation units that do not include the
851 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]852
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]853<p>As SSA values, global variables define pointer values that are in scope
854 (i.e. they dominate) all basic blocks in the program. Global variables
855 always define a pointer to their "content" type because they describe a
856 region of memory, and all memory objects in LLVM are accessed through
857 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]858
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]859<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
860 that the address is not significant, only the content. Constants marked
Rafael Espindolaf1ed7812011-01-15 08:20:57 +0000[diff] [blame]861 like this can be merged with other constants if they have the same
862 initializer. Note that a constant with significant address <em>can</em>
863 be merged with a <tt>unnamed_addr</tt> constant, the result being a
864 constant whose address is significant.</p>
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]865
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]866<p>A global variable may be declared to reside in a target-specific numbered
867 address space. For targets that support them, address spaces may affect how
868 optimizations are performed and/or what target instructions are used to
869 access the variable. The default address space is zero. The address space
870 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]871
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]872<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]873 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]874
Chris Lattner78e00bc2010-04-28 00:13:42 +0000[diff] [blame]875<p>An explicit alignment may be specified for a global, which must be a power
876 of 2. If not present, or if the alignment is set to zero, the alignment of
877 the global is set by the target to whatever it feels convenient. If an
878 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner4bd85e42010-04-28 00:31:12 +0000[diff] [blame]879 alignment. Targets and optimizers are not allowed to over-align the global
880 if the global has an assigned section. In this case, the extra alignment
881 could be observable: for example, code could assume that the globals are
882 densely packed in their section and try to iterate over them as an array,
883 alignment padding would break this iteration.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]884
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]885<p>For example, the following defines a global in a numbered address space with
886 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]887
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]888<pre class="doc_code">
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]889@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]890</pre>
891
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]892</div>
893
894
895<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]896<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]897 <a name="functionstructure">Functions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]898</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]899
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]900<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]901
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]902<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]903 optional <a href="#linkage">linkage type</a>, an optional
904 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]905 <a href="#callingconv">calling convention</a>,
906 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]907 <a href="#paramattrs">parameter attribute</a> for the return type, a function
908 name, a (possibly empty) argument list (each with optional
909 <a href="#paramattrs">parameter attributes</a>), optional
910 <a href="#fnattrs">function attributes</a>, an optional section, an optional
911 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
912 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]913
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]914<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
915 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]916 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]917 <a href="#callingconv">calling convention</a>,
918 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]919 <a href="#paramattrs">parameter attribute</a> for the return type, a function
920 name, a possibly empty list of arguments, an optional alignment, and an
921 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]922
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]923<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]924 (Control Flow Graph) for the function. Each basic block may optionally start
925 with a label (giving the basic block a symbol table entry), contains a list
926 of instructions, and ends with a <a href="#terminators">terminator</a>
927 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]928
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]929<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]930 executed on entrance to the function, and it is not allowed to have
931 predecessor basic blocks (i.e. there can not be any branches to the entry
932 block of a function). Because the block can have no predecessors, it also
933 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]934
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]935<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]936 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]937
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]938<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]939 the alignment is set to zero, the alignment of the function is set by the
940 target to whatever it feels convenient. If an explicit alignment is
941 specified, the function is forced to have at least that much alignment. All
942 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]943
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]944<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
945 be significant and two identical functions can be merged</p>.
946
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]947<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]948<pre class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]949define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]950 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
951 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
952 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
953 [<a href="#gc">gc</a>] { ... }
954</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]955
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]956</div>
957
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]958<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]959<h3>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]960 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]961</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]962
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]963<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]964
965<p>Aliases act as "second name" for the aliasee value (which can be either
966 function, global variable, another alias or bitcast of global value). Aliases
967 may have an optional <a href="#linkage">linkage type</a>, and an
968 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]969
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]970<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]971<pre class="doc_code">
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]972@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]973</pre>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]974
975</div>
976
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]977<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]978<h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]979 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]980</h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]981
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]982<div>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]983
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]984<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]985 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]986 a named metadata.</p>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]987
988<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]989<pre class="doc_code">
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]990; Some unnamed metadata nodes, which are referenced by the named metadata.
991!0 = metadata !{metadata !"zero"}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]992!1 = metadata !{metadata !"one"}
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]993!2 = metadata !{metadata !"two"}
Dan Gohman58cd65f2010-07-13 19:48:13 +0000[diff] [blame]994; A named metadata.
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]995!name = !{!0, !1, !2}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]996</pre>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]997
998</div>
999
1000<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1001<h3>
1002 <a name="paramattrs">Parameter Attributes</a>
1003</h3>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1004
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1005<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1006
1007<p>The return type and each parameter of a function type may have a set of
1008 <i>parameter attributes</i> associated with them. Parameter attributes are
1009 used to communicate additional information about the result or parameters of
1010 a function. Parameter attributes are considered to be part of the function,
1011 not of the function type, so functions with different parameter attributes
1012 can have the same function type.</p>
1013
1014<p>Parameter attributes are simple keywords that follow the type specified. If
1015 multiple parameter attributes are needed, they are space separated. For
1016 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1017
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1018<pre class="doc_code">
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]1019declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]1020declare i32 @atoi(i8 zeroext)
1021declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1022</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1023
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1024<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1025 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1026
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1027<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1028
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1029<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1030 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1031 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichac106272011-03-16 22:20:18 +0000[diff] [blame]1032 should be zero-extended to the extent required by the target's ABI (which
1033 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1034 parameter) or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1035
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1036 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1037 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich341c36d2011-03-17 14:21:58 +0000[diff] [blame]1038 should be sign-extended to the extent required by the target's ABI (which
1039 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1040 return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1041
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1042 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1043 <dd>This indicates that this parameter or return value should be treated in a
1044 special target-dependent fashion during while emitting code for a function
1045 call or return (usually, by putting it in a register as opposed to memory,
1046 though some targets use it to distinguish between two different kinds of
1047 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1048
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1049 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1050 <dd><p>This indicates that the pointer parameter should really be passed by
1051 value to the function. The attribute implies that a hidden copy of the
1052 pointee
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1053 is made between the caller and the callee, so the callee is unable to
1054 modify the value in the callee. This attribute is only valid on LLVM
1055 pointer arguments. It is generally used to pass structs and arrays by
1056 value, but is also valid on pointers to scalars. The copy is considered
1057 to belong to the caller not the callee (for example,
1058 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1059 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1060 values.</p>
1061
1062 <p>The byval attribute also supports specifying an alignment with
1063 the align attribute. It indicates the alignment of the stack slot to
1064 form and the known alignment of the pointer specified to the call site. If
1065 the alignment is not specified, then the code generator makes a
1066 target-specific assumption.</p></dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1067
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1068 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1069 <dd>This indicates that the pointer parameter specifies the address of a
1070 structure that is the return value of the function in the source program.
1071 This pointer must be guaranteed by the caller to be valid: loads and
1072 stores to the structure may be assumed by the callee to not to trap. This
1073 may only be applied to the first parameter. This is not a valid attribute
1074 for return values. </dd>
1075
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1076 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1077 <dd>This indicates that pointer values
1078 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmande256292010-07-02 23:46:54 +0000[diff] [blame]1079 value do not alias pointer values which are not <i>based</i> on it,
1080 ignoring certain "irrelevant" dependencies.
1081 For a call to the parent function, dependencies between memory
1082 references from before or after the call and from those during the call
1083 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1084 return value used in that call.
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1085 The caller shares the responsibility with the callee for ensuring that
1086 these requirements are met.
1087 For further details, please see the discussion of the NoAlias response in
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1088 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1089<br>
John McCall72ed8902010-07-06 21:07:14 +0000[diff] [blame]1090 Note that this definition of <tt>noalias</tt> is intentionally
1091 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner5eff9ca2010-07-06 20:51:35 +0000[diff] [blame]1092 arguments, though it is slightly weaker.
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1093<br>
1094 For function return values, C99's <tt>restrict</tt> is not meaningful,
1095 while LLVM's <tt>noalias</tt> is.
1096 </dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1097
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1098 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1099 <dd>This indicates that the callee does not make any copies of the pointer
1100 that outlive the callee itself. This is not a valid attribute for return
1101 values.</dd>
1102
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1103 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1104 <dd>This indicates that the pointer parameter can be excised using the
1105 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1106 attribute for return values.</dd>
1107</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1108
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1109</div>
1110
1111<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1112<h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1113 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1114</h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1115
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1116<div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1117
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1118<p>Each function may specify a garbage collector name, which is simply a
1119 string:</p>
1120
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1121<pre class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1122define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1123</pre>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1124
1125<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1126 collector which will cause the compiler to alter its output in order to
1127 support the named garbage collection algorithm.</p>
1128
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1129</div>
1130
1131<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1132<h3>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1133 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1134</h3>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1135
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1136<div>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1137
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1138<p>Function attributes are set to communicate additional information about a
1139 function. Function attributes are considered to be part of the function, not
1140 of the function type, so functions with different parameter attributes can
1141 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1142
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1143<p>Function attributes are simple keywords that follow the type specified. If
1144 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1145
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1146<pre class="doc_code">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1147define void @f() noinline { ... }
1148define void @f() alwaysinline { ... }
1149define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1150define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1151</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1152
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1153<dl>
Charles Davisbe5557e2010-02-12 00:31:15 +0000[diff] [blame]1154 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1155 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1156 the backend should forcibly align the stack pointer. Specify the
1157 desired alignment, which must be a power of two, in parentheses.
1158
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1159 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1160 <dd>This attribute indicates that the inliner should attempt to inline this
1161 function into callers whenever possible, ignoring any active inlining size
1162 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1163
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1164 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis1b2d3722010-10-25 16:29:03 +0000[diff] [blame]1165 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis74205252010-10-25 19:07:39 +0000[diff] [blame]1166 meaning the function can be patched and/or hooked even while it is
1167 loaded into memory. On x86, the function prologue will be preceded
1168 by six bytes of padding and will begin with a two-byte instruction.
1169 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1170 higher were compiled in this fashion.</dd>
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1171
Dan Gohman8bd11f12011-06-16 16:03:13 +0000[diff] [blame]1172 <dt><tt><b>nonlazybind</b></tt></dt>
1173 <dd>This attribute suppresses lazy symbol binding for the function. This
1174 may make calls to the function faster, at the cost of extra program
1175 startup time if the function is not called during program startup.</dd>
1176
Jakob Stoklund Olesen74bb06c2010-02-06 01:16:28 +0000[diff] [blame]1177 <dt><tt><b>inlinehint</b></tt></dt>
1178 <dd>This attribute indicates that the source code contained a hint that inlining
1179 this function is desirable (such as the "inline" keyword in C/C++). It
1180 is just a hint; it imposes no requirements on the inliner.</dd>
1181
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1182 <dt><tt><b>naked</b></tt></dt>
1183 <dd>This attribute disables prologue / epilogue emission for the function.
1184 This can have very system-specific consequences.</dd>
1185
1186 <dt><tt><b>noimplicitfloat</b></tt></dt>
1187 <dd>This attributes disables implicit floating point instructions.</dd>
1188
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1189 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1190 <dd>This attribute indicates that the inliner should never inline this
1191 function in any situation. This attribute may not be used together with
1192 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1193
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1194 <dt><tt><b>noredzone</b></tt></dt>
1195 <dd>This attribute indicates that the code generator should not use a red
1196 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1197
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1198 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1199 <dd>This function attribute indicates that the function never returns
1200 normally. This produces undefined behavior at runtime if the function
1201 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1202
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1203 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1204 <dd>This function attribute indicates that the function never returns with an
1205 unwind or exceptional control flow. If the function does unwind, its
1206 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1207
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1208 <dt><tt><b>optsize</b></tt></dt>
1209 <dd>This attribute suggests that optimization passes and code generator passes
1210 make choices that keep the code size of this function low, and otherwise
1211 do optimizations specifically to reduce code size.</dd>
1212
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1213 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1214 <dd>This attribute indicates that the function computes its result (or decides
1215 to unwind an exception) based strictly on its arguments, without
1216 dereferencing any pointer arguments or otherwise accessing any mutable
1217 state (e.g. memory, control registers, etc) visible to caller functions.
1218 It does not write through any pointer arguments
1219 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1220 changes any state visible to callers. This means that it cannot unwind
1221 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1222 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1223
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1224 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1225 <dd>This attribute indicates that the function does not write through any
1226 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1227 arguments) or otherwise modify any state (e.g. memory, control registers,
1228 etc) visible to caller functions. It may dereference pointer arguments
1229 and read state that may be set in the caller. A readonly function always
1230 returns the same value (or unwinds an exception identically) when called
1231 with the same set of arguments and global state. It cannot unwind an
1232 exception by calling the <tt>C++</tt> exception throwing methods, but may
1233 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1234
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1235 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1236 <dd>This attribute indicates that the function should emit a stack smashing
1237 protector. It is in the form of a "canary"&mdash;a random value placed on
1238 the stack before the local variables that's checked upon return from the
1239 function to see if it has been overwritten. A heuristic is used to
1240 determine if a function needs stack protectors or not.<br>
1241<br>
1242 If a function that has an <tt>ssp</tt> attribute is inlined into a
1243 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1244 function will have an <tt>ssp</tt> attribute.</dd>
1245
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1246 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1247 <dd>This attribute indicates that the function should <em>always</em> emit a
1248 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1249 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1250<br>
1251 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1252 function that doesn't have an <tt>sspreq</tt> attribute or which has
1253 an <tt>ssp</tt> attribute, then the resulting function will have
1254 an <tt>sspreq</tt> attribute.</dd>
Rafael Espindola163d6752011-07-25 15:27:59 +0000[diff] [blame]1255
1256 <dt><tt><b><a name="uwtable">uwtable</a></b></tt></dt>
1257 <dd>This attribute indicates that the ABI being targeted requires that
1258 an unwind table entry be produce for this function even if we can
1259 show that no exceptions passes by it. This is normally the case for
1260 the ELF x86-64 abi, but it can be disabled for some compilation
1261 units.</dd>
1262
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1263</dl>
1264
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1265</div>
1266
1267<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1268<h3>
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1269 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1270</h3>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1271
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1272<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1273
1274<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1275 the GCC "file scope inline asm" blocks. These blocks are internally
1276 concatenated by LLVM and treated as a single unit, but may be separated in
1277 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1278
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1279<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1280module asm "inline asm code goes here"
1281module asm "more can go here"
1282</pre>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1283
1284<p>The strings can contain any character by escaping non-printable characters.
1285 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]1286 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1287
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1288<p>The inline asm code is simply printed to the machine code .s file when
1289 assembly code is generated.</p>
1290
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1291</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1292
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1293<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1294<h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1295 <a name="datalayout">Data Layout</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1296</h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1297
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1298<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1299
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1300<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1301 data is to be laid out in memory. The syntax for the data layout is
1302 simply:</p>
1303
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1304<pre class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1305target datalayout = "<i>layout specification</i>"
1306</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1307
1308<p>The <i>layout specification</i> consists of a list of specifications
1309 separated by the minus sign character ('-'). Each specification starts with
1310 a letter and may include other information after the letter to define some
1311 aspect of the data layout. The specifications accepted are as follows:</p>
1312
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1313<dl>
1314 <dt><tt>E</tt></dt>
1315 <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]1316 bits with the most significance have the lowest address location.</dd>
1317
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1318 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1319 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1320 the bits with the least significance have the lowest address
1321 location.</dd>
1322
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1323 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1324 <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]1325 <i>preferred</i> alignments. All sizes are in bits. Specifying
1326 the <i>pref</i> alignment is optional. If omitted, the
1327 preceding <tt>:</tt> should be omitted too.</dd>
1328
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1329 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1330 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1331 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1332
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1333 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1334 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1335 <i>size</i>.</dd>
1336
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1337 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1338 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesence522852010-05-28 18:54:47 +0000[diff] [blame]1339 <i>size</i>. Only values of <i>size</i> that are supported by the target
1340 will work. 32 (float) and 64 (double) are supported on all targets;
1341 80 or 128 (different flavors of long double) are also supported on some
1342 targets.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1343
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1344 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1345 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1346 <i>size</i>.</dd>
1347
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1348 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1349 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1350 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1351
1352 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1353 <dd>This specifies a set of native integer widths for the target CPU
1354 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1355 "n32:64" for PowerPC 64, or "n8:16:32:64" for X86-64. Elements of
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1356 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1357 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1358</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1359
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1360<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]1361 default set of specifications which are then (possibly) overridden by the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1362 specifications in the <tt>datalayout</tt> keyword. The default specifications
1363 are given in this list:</p>
1364
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1365<ul>
1366 <li><tt>E</tt> - big endian</li>
Dan Gohman8ad777d2010-02-23 02:44:03 +0000[diff] [blame]1367 <li><tt>p:64:64:64</tt> - 64-bit pointers with 64-bit alignment</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1368 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1369 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1370 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1371 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1372 <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]1373 alignment of 64-bits</li>
1374 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1375 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1376 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1377 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1378 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1379 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1380</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1381
1382<p>When LLVM is determining the alignment for a given type, it uses the
1383 following rules:</p>
1384
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1385<ol>
1386 <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]1387 specification is used.</li>
1388
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1389 <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]1390 smallest integer type that is larger than the bitwidth of the sought type
1391 is used. If none of the specifications are larger than the bitwidth then
1392 the the largest integer type is used. For example, given the default
1393 specifications above, the i7 type will use the alignment of i8 (next
1394 largest) while both i65 and i256 will use the alignment of i64 (largest
1395 specified).</li>
1396
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1397 <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]1398 largest vector type that is smaller than the sought vector type will be
1399 used as a fall back. This happens because &lt;128 x double&gt; can be
1400 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1401</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1402
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1403</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1404
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1405<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1406<h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1407 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1408</h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1409
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1410<div>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1411
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1412<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1413with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1414is undefined. Pointer values are associated with address ranges
1415according to the following rules:</p>
1416
1417<ul>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1418 <li>A pointer value is associated with the addresses associated with
1419 any value it is <i>based</i> on.
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1420 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1421 range of the variable's storage.</li>
1422 <li>The result value of an allocation instruction is associated with
1423 the address range of the allocated storage.</li>
1424 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1425 no address.</li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1426 <li>An integer constant other than zero or a pointer value returned
1427 from a function not defined within LLVM may be associated with address
1428 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1429 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1430 allocated by mechanisms provided by LLVM.</li>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1431</ul>
1432
1433<p>A pointer value is <i>based</i> on another pointer value according
1434 to the following rules:</p>
1435
1436<ul>
1437 <li>A pointer value formed from a
1438 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1439 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1440 <li>The result value of a
1441 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1442 of the <tt>bitcast</tt>.</li>
1443 <li>A pointer value formed by an
1444 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1445 pointer values that contribute (directly or indirectly) to the
1446 computation of the pointer's value.</li>
1447 <li>The "<i>based</i> on" relationship is transitive.</li>
1448</ul>
1449
1450<p>Note that this definition of <i>"based"</i> is intentionally
1451 similar to the definition of <i>"based"</i> in C99, though it is
1452 slightly weaker.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1453
1454<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1455<tt><a href="#i_load">load</a></tt> merely indicates the size and
1456alignment of the memory from which to load, as well as the
Dan Gohman4eb47192010-06-17 19:23:50 +0000[diff] [blame]1457interpretation of the value. The first operand type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1458<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1459and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1460
1461<p>Consequently, type-based alias analysis, aka TBAA, aka
1462<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1463LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1464additional information which specialized optimization passes may use
1465to implement type-based alias analysis.</p>
1466
1467</div>
1468
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1469<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1470<h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1471 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1472</h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1473
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1474<div>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1475
1476<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1477href="#i_store"><tt>store</tt></a>s, and <a
1478href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1479The optimizers must not change the number of volatile operations or change their
1480order of execution relative to other volatile operations. The optimizers
1481<i>may</i> change the order of volatile operations relative to non-volatile
1482operations. This is not Java's "volatile" and has no cross-thread
1483synchronization behavior.</p>
1484
1485</div>
1486
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1487<!-- ======================================================================= -->
1488<h3>
1489 <a name="memmodel">Memory Model for Concurrent Operations</a>
1490</h3>
1491
1492<div>
1493
1494<p>The LLVM IR does not define any way to start parallel threads of execution
1495or to register signal handlers. Nonetheless, there are platform-specific
1496ways to create them, and we define LLVM IR's behavior in their presence. This
1497model is inspired by the C++0x memory model.</p>
1498
1499<p>We define a <i>happens-before</i> partial order as the least partial order
1500that</p>
1501<ul>
1502 <li>Is a superset of single-thread program order, and</li>
1503 <li>When a <i>synchronizes-with</i> <tt>b</tt>, includes an edge from
1504 <tt>a</tt> to <tt>b</tt>. <i>Synchronizes-with</i> pairs are introduced
1505 by platform-specific techniques, like pthread locks, thread
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1506 creation, thread joining, etc., and by atomic instructions.
1507 (See also <a href="#ordering">Atomic Memory Ordering Constraints</a>).
1508 </li>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1509</ul>
1510
1511<p>Note that program order does not introduce <i>happens-before</i> edges
1512between a thread and signals executing inside that thread.</p>
1513
1514<p>Every (defined) read operation (load instructions, memcpy, atomic
1515loads/read-modify-writes, etc.) <var>R</var> reads a series of bytes written by
1516(defined) write operations (store instructions, atomic
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1517stores/read-modify-writes, memcpy, etc.). For the purposes of this section,
1518initialized globals are considered to have a write of the initializer which is
1519atomic and happens before any other read or write of the memory in question.
1520For each byte of a read <var>R</var>, <var>R<sub>byte</sub></var> may see
1521any write to the same byte, except:</p>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1522
1523<ul>
1524 <li>If <var>write<sub>1</sub></var> happens before
1525 <var>write<sub>2</sub></var>, and <var>write<sub>2</sub></var> happens
1526 before <var>R<sub>byte</sub></var>, then <var>R<sub>byte</sub></var>
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1527 does not see <var>write<sub>1</sub></var>.
Bill Wendling537603b2011-07-31 06:45:03 +0000[diff] [blame]1528 <li>If <var>R<sub>byte</sub></var> happens before
1529 <var>write<sub>3</sub></var>, then <var>R<sub>byte</sub></var> does not
1530 see <var>write<sub>3</sub></var>.
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1531</ul>
1532
1533<p>Given that definition, <var>R<sub>byte</sub></var> is defined as follows:
1534<ul>
1535 <li>If there is no write to the same byte that happens before
1536 <var>R<sub>byte</sub></var>, <var>R<sub>byte</sub></var> returns
1537 <tt>undef</tt> for that byte.
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1538 <li>Otherwise, if <var>R<sub>byte</sub></var> may see exactly one write,
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1539 <var>R<sub>byte</sub></var> returns the value written by that
1540 write.</li>
Eli Friedmanf12e4e92011-07-22 03:04:45 +0000[diff] [blame]1541 <li>Otherwise, if <var>R</var> is atomic, and all the writes
1542 <var>R<sub>byte</sub></var> may see are atomic, it chooses one of the
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1543 values written. See the <a href="#ordering">Atomic Memory Ordering
1544 Constraints</a> section for additional constraints on how the choice
1545 is made.
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1546 <li>Otherwise <var>R<sub>byte</sub></var> returns <tt>undef</tt>.</li>
1547</ul>
1548
1549<p><var>R</var> returns the value composed of the series of bytes it read.
1550This implies that some bytes within the value may be <tt>undef</tt>
1551<b>without</b> the entire value being <tt>undef</tt>. Note that this only
1552defines the semantics of the operation; it doesn't mean that targets will
1553emit more than one instruction to read the series of bytes.</p>
1554
1555<p>Note that in cases where none of the atomic intrinsics are used, this model
1556places only one restriction on IR transformations on top of what is required
1557for single-threaded execution: introducing a store to a byte which might not
Eli Friedman4bc9f3c2011-08-02 01:15:34 +0000[diff] [blame]1558otherwise be stored is not allowed in general. (Specifically, in the case
1559where another thread might write to and read from an address, introducing a
1560store can change a load that may see exactly one write into a load that may
1561see multiple writes.)</p>
Eli Friedman35b54aa2011-07-20 21:35:53 +0000[diff] [blame]1562
1563<!-- FIXME: This model assumes all targets where concurrency is relevant have
1564a byte-size store which doesn't affect adjacent bytes. As far as I can tell,
1565none of the backends currently in the tree fall into this category; however,
1566there might be targets which care. If there are, we want a paragraph
1567like the following:
1568
1569Targets may specify that stores narrower than a certain width are not
1570available; on such a target, for the purposes of this model, treat any
1571non-atomic write with an alignment or width less than the minimum width
1572as if it writes to the relevant surrounding bytes.
1573-->
1574
1575</div>
1576
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]1577<!-- ======================================================================= -->
1578<div class="doc_subsection">
1579 <a name="ordering">Atomic Memory Ordering Constraints</a>
1580</div>
1581
1582<div class="doc_text">
1583
1584<p>Atomic instructions (<a href="#i_cmpxchg"><code>cmpxchg</code></a>,
1585<a href="#i_atomicrmw"><code>atomicrmw</code></a>, and
1586<a href="#i_fence"><code>fence</code></a>) take an ordering parameter
1587that determines which other atomic instructions on the same address they
1588<i>synchronize with</i>. These semantics are borrowed from Java and C++0x,
1589but are somewhat more colloquial. If these descriptions aren't precise enough,
1590check those specs. <a href="#i_fence"><code>fence</code></a> instructions
1591treat these orderings somewhat differently since they don't take an address.
1592See that instruction's documentation for details.</p>
1593
1594<!-- FIXME Note atomic load+store here once those get added. -->
1595
1596<dl>
1597<!-- FIXME: unordered is intended to be used for atomic load and store;
1598it isn't allowed for any instruction yet. -->
1599<dt><code>unordered</code></dt>
1600<dd>The set of values that can be read is governed by the happens-before
1601partial order. A value cannot be read unless some operation wrote it.
1602This is intended to provide a guarantee strong enough to model Java's
1603non-volatile shared variables. This ordering cannot be specified for
1604read-modify-write operations; it is not strong enough to make them atomic
1605in any interesting way.</dd>
1606<dt><code>monotonic</code></dt>
1607<dd>In addition to the guarantees of <code>unordered</code>, there is a single
1608total order for modifications by <code>monotonic</code> operations on each
1609address. All modification orders must be compatible with the happens-before
1610order. There is no guarantee that the modification orders can be combined to
1611a global total order for the whole program (and this often will not be
1612possible). The read in an atomic read-modify-write operation
1613(<a href="#i_cmpxchg"><code>cmpxchg</code></a> and
1614<a href="#i_atomicrmw"><code>atomicrmw</code></a>)
1615reads the value in the modification order immediately before the value it
1616writes. If one atomic read happens before another atomic read of the same
1617address, the later read must see the same value or a later value in the
1618address's modification order. This disallows reordering of
1619<code>monotonic</code> (or stronger) operations on the same address. If an
1620address is written <code>monotonic</code>ally by one thread, and other threads
1621<code>monotonic</code>ally read that address repeatedly, the other threads must
1622eventually see the write. This is intended to model C++'s relaxed atomic
1623variables.</dd>
1624<dt><code>acquire</code></dt>
1625<dd>In addition to the guarantees of <code>monotonic</code>, if this operation
1626reads a value written by a <code>release</code> atomic operation, it
1627<i>synchronizes-with</i> that operation.</dd>
1628<dt><code>release</code></dt>
1629<dd>In addition to the guarantees of <code>monotonic</code>,
1630a <i>synchronizes-with</i> edge may be formed by an <code>acquire</code>
1631operation.</dd>
1632<dt><code>acq_rel</code> (acquire+release)</dt><dd>Acts as both an
1633<code>acquire</code> and <code>release</code> operation on its address.</dd>
1634<dt><code>seq_cst</code> (sequentially consistent)</dt><dd>
1635<dd>In addition to the guarantees of <code>acq_rel</code>
1636(<code>acquire</code> for an operation which only reads, <code>release</code>
1637for an operation which only writes), there is a global total order on all
1638sequentially-consistent operations on all addresses, which is consistent with
1639the <i>happens-before</i> partial order and with the modification orders of
1640all the affected addresses. Each sequentially-consistent read sees the last
1641preceding write to the same address in this global order. This is intended
1642to model C++'s sequentially-consistent atomic variables and Java's volatile
1643shared variables.</dd>
1644</dl>
1645
1646<p id="singlethread">If an atomic operation is marked <code>singlethread</code>,
1647it only <i>synchronizes with</i> or participates in modification and seq_cst
1648total orderings with other operations running in the same thread (for example,
1649in signal handlers).</p>
1650
1651</div>
1652
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1653</div>
1654
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1655<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1656<h2><a name="typesystem">Type System</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1657<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1658
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1659<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1660
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1661<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1662 intermediate representation. Being typed enables a number of optimizations
1663 to be performed on the intermediate representation directly, without having
1664 to do extra analyses on the side before the transformation. A strong type
1665 system makes it easier to read the generated code and enables novel analyses
1666 and transformations that are not feasible to perform on normal three address
1667 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1668
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1669<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1670<h3>
1671 <a name="t_classifications">Type Classifications</a>
1672</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1673
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1674<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1675
1676<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1677
1678<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1679 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1680 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1681 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1682 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1683 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1684 </tr>
1685 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1686 <td><a href="#t_floating">floating point</a></td>
1687 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1688 </tr>
1689 <tr>
1690 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1691 <td><a href="#t_integer">integer</a>,
1692 <a href="#t_floating">floating point</a>,
1693 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1694 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1695 <a href="#t_struct">structure</a>,
1696 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1697 <a href="#t_label">label</a>,
1698 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1699 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1700 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1701 <tr>
1702 <td><a href="#t_primitive">primitive</a></td>
1703 <td><a href="#t_label">label</a>,
1704 <a href="#t_void">void</a>,
Tobias Grosser4c8c95b2010-12-28 20:29:31 +0000[diff] [blame]1705 <a href="#t_integer">integer</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1706 <a href="#t_floating">floating point</a>,
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1707 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1708 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1709 </tr>
1710 <tr>
1711 <td><a href="#t_derived">derived</a></td>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1712 <td><a href="#t_array">array</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1713 <a href="#t_function">function</a>,
1714 <a href="#t_pointer">pointer</a>,
1715 <a href="#t_struct">structure</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1716 <a href="#t_vector">vector</a>,
1717 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1718 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1719 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1720 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1721</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1722
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1723<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1724 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1725 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1726
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1727</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1728
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1729<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1730<h3>
1731 <a name="t_primitive">Primitive Types</a>
1732</h3>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1733
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1734<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1735
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1736<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1737 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1738
1739<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1740<h4>
1741 <a name="t_integer">Integer Type</a>
1742</h4>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1743
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1744<div>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1745
1746<h5>Overview:</h5>
1747<p>The integer type is a very simple type that simply specifies an arbitrary
1748 bit width for the integer type desired. Any bit width from 1 bit to
1749 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1750
1751<h5>Syntax:</h5>
1752<pre>
1753 iN
1754</pre>
1755
1756<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1757 value.</p>
1758
1759<h5>Examples:</h5>
1760<table class="layout">
1761 <tr class="layout">
1762 <td class="left"><tt>i1</tt></td>
1763 <td class="left">a single-bit integer.</td>
1764 </tr>
1765 <tr class="layout">
1766 <td class="left"><tt>i32</tt></td>
1767 <td class="left">a 32-bit integer.</td>
1768 </tr>
1769 <tr class="layout">
1770 <td class="left"><tt>i1942652</tt></td>
1771 <td class="left">a really big integer of over 1 million bits.</td>
1772 </tr>
1773</table>
1774
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1775</div>
1776
1777<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1778<h4>
1779 <a name="t_floating">Floating Point Types</a>
1780</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1781
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1782<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1783
1784<table>
1785 <tbody>
1786 <tr><th>Type</th><th>Description</th></tr>
1787 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1788 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1789 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1790 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1791 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1792 </tbody>
1793</table>
1794
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1795</div>
1796
1797<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1798<h4>
1799 <a name="t_x86mmx">X86mmx Type</a>
1800</h4>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1801
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1802<div>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1803
1804<h5>Overview:</h5>
1805<p>The x86mmx type represents a value held in an MMX register on an x86 machine. The operations allowed on it are quite limited: parameters and return values, load and store, and bitcast. User-specified MMX instructions are represented as intrinsic or asm calls with arguments and/or results of this type. There are no arrays, vectors or constants of this type.</p>
1806
1807<h5>Syntax:</h5>
1808<pre>
Dale Johannesenb1f0ff12010-10-01 01:07:02 +0000[diff] [blame]1809 x86mmx
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1810</pre>
1811
1812</div>
1813
1814<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1815<h4>
1816 <a name="t_void">Void Type</a>
1817</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1818
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1819<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1820
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1821<h5>Overview:</h5>
1822<p>The void type does not represent any value and has no size.</p>
1823
1824<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1825<pre>
1826 void
1827</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1828
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1829</div>
1830
1831<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1832<h4>
1833 <a name="t_label">Label Type</a>
1834</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1835
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1836<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1837
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1838<h5>Overview:</h5>
1839<p>The label type represents code labels.</p>
1840
1841<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1842<pre>
1843 label
1844</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1845
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1846</div>
1847
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1848<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1849<h4>
1850 <a name="t_metadata">Metadata Type</a>
1851</h4>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1852
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1853<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1854
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1855<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1856<p>The metadata type represents embedded metadata. No derived types may be
1857 created from metadata except for <a href="#t_function">function</a>
1858 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1859
1860<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1861<pre>
1862 metadata
1863</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1864
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1865</div>
1866
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1867</div>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1868
1869<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1870<h3>
1871 <a name="t_derived">Derived Types</a>
1872</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1873
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1874<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1875
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1876<p>The real power in LLVM comes from the derived types in the system. This is
1877 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1878 useful types. Each of these types contain one or more element types which
1879 may be a primitive type, or another derived type. For example, it is
1880 possible to have a two dimensional array, using an array as the element type
1881 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1882
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]1883</div>
1884
1885
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1886<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1887<h4>
1888 <a name="t_aggregate">Aggregate Types</a>
1889</h4>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1890
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1891<div>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1892
1893<p>Aggregate Types are a subset of derived types that can contain multiple
1894 member types. <a href="#t_array">Arrays</a>,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]1895 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1896 aggregate types.</p>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1897
1898</div>
1899
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1900<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1901<h4>
1902 <a name="t_array">Array Type</a>
1903</h4>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1904
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1905<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1906
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1907<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1908<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1909 sequentially in memory. The array type requires a size (number of elements)
1910 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1911
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1912<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1913<pre>
1914 [&lt;# elements&gt; x &lt;elementtype&gt;]
1915</pre>
1916
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1917<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1918 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1919
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1920<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1921<table class="layout">
1922 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1923 <td class="left"><tt>[40 x i32]</tt></td>
1924 <td class="left">Array of 40 32-bit integer values.</td>
1925 </tr>
1926 <tr class="layout">
1927 <td class="left"><tt>[41 x i32]</tt></td>
1928 <td class="left">Array of 41 32-bit integer values.</td>
1929 </tr>
1930 <tr class="layout">
1931 <td class="left"><tt>[4 x i8]</tt></td>
1932 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1933 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1934</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1935<p>Here are some examples of multidimensional arrays:</p>
1936<table class="layout">
1937 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1938 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1939 <td class="left">3x4 array of 32-bit integer values.</td>
1940 </tr>
1941 <tr class="layout">
1942 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1943 <td class="left">12x10 array of single precision floating point values.</td>
1944 </tr>
1945 <tr class="layout">
1946 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1947 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1948 </tr>
1949</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1950
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1951<p>There is no restriction on indexing beyond the end of the array implied by
1952 a static type (though there are restrictions on indexing beyond the bounds
1953 of an allocated object in some cases). This means that single-dimension
1954 'variable sized array' addressing can be implemented in LLVM with a zero
1955 length array type. An implementation of 'pascal style arrays' in LLVM could
1956 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1957
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1958</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1959
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1960<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1961<h4>
1962 <a name="t_function">Function Type</a>
1963</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1964
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1965<div>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1966
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1967<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1968<p>The function type can be thought of as a function signature. It consists of
1969 a return type and a list of formal parameter types. The return type of a
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]1970 function type is a first class type or a void type.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1971
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1972<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1973<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1974 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1975</pre>
1976
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1977<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]1978 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1979 which indicates that the function takes a variable number of arguments.
1980 Variable argument functions can access their arguments with
1981 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1982 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1983 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1984
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1985<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1986<table class="layout">
1987 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1988 <td class="left"><tt>i32 (i32)</tt></td>
1989 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1990 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1991 </tr><tr class="layout">
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1992 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1993 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1994 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1995 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1996 returning <tt>float</tt>.
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1997 </td>
1998 </tr><tr class="layout">
1999 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2000 <td class="left">A vararg function that takes at least one
2001 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
2002 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]2003 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2004 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]2005 </tr><tr class="layout">
2006 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]2007 <td class="left">A function taking an <tt>i32</tt>, returning a
2008 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]2009 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2010 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2011</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2012
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2013</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2014
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2015<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2016<h4>
2017 <a name="t_struct">Structure Type</a>
2018</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2019
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2020<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2021
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2022<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2023<p>The structure type is used to represent a collection of data members together
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2024 in memory. The elements of a structure may be any type that has a size.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2025
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]2026<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
2027 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
2028 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
2029 Structures in registers are accessed using the
2030 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
2031 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2032
2033<p>Structures may optionally be "packed" structures, which indicate that the
2034 alignment of the struct is one byte, and that there is no padding between
2035 the elements. In non-packed structs, padding between field types is defined
2036 by the target data string to match the underlying processor.</p>
2037
2038<p>Structures can either be "anonymous" or "named". An anonymous structure is
2039 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) and a named types
2040 are always defined at the top level with a name. Anonmyous types are uniqued
2041 by their contents and can never be recursive since there is no way to write
2042 one. Named types can be recursive.
2043</p>
2044
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2045<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2046<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2047 %T1 = type { &lt;type list&gt; } <i>; Named normal struct type</i>
2048 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Named packed struct type</i>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2049</pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2050
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2051<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2052<table class="layout">
2053 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2054 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
2055 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2056 </tr>
2057 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2058 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
2059 <td class="left">A pair, where the first element is a <tt>float</tt> and the
2060 second element is a <a href="#t_pointer">pointer</a> to a
2061 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
2062 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2063 </tr>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2064 <tr class="layout">
2065 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
2066 <td class="left">A packed struct known to be 5 bytes in size.</td>
2067 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2068</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2069
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2070</div>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2071
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2072<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2073<h4>
Chris Lattner2a843822011-07-23 19:59:08 +0000[diff] [blame]2074 <a name="t_opaque">Opaque Structure Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2075</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2076
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2077<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2078
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2079<h5>Overview:</h5>
Chris Lattner2a843822011-07-23 19:59:08 +0000[diff] [blame]2080<p>Opaque structure types are used to represent named structure types that do
2081 not have a body specified. This corresponds (for example) to the C notion of
2082 a forward declared structure.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2083
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2084<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2085<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2086 %X = type opaque
2087 %52 = type opaque
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2088</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2089
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2090<h5>Examples:</h5>
2091<table class="layout">
2092 <tr class="layout">
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2093 <td class="left"><tt>opaque</tt></td>
2094 <td class="left">An opaque type.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2095 </tr>
2096</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2097
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2098</div>
2099
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame]2100
2101
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]2102<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2103<h4>
2104 <a name="t_pointer">Pointer Type</a>
2105</h4>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2106
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2107<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2108
2109<h5>Overview:</h5>
Dan Gohman88481112010-02-25 16:50:07 +0000[diff] [blame]2110<p>The pointer type is used to specify memory locations.
2111 Pointers are commonly used to reference objects in memory.</p>
2112
2113<p>Pointer types may have an optional address space attribute defining the
2114 numbered address space where the pointed-to object resides. The default
2115 address space is number zero. The semantics of non-zero address
2116 spaces are target-specific.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2117
2118<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
2119 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]2120
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2121<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2122<pre>
2123 &lt;type&gt; *
2124</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2125
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2126<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2127<table class="layout">
2128 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2129 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2130 <td class="left">A <a href="#t_pointer">pointer</a> to <a
2131 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
2132 </tr>
2133 <tr class="layout">
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]2134 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2135 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2136 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2137 <tt>i32</tt>.</td>
2138 </tr>
2139 <tr class="layout">
2140 <td class="left"><tt>i32 addrspace(5)*</tt></td>
2141 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
2142 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2143 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2144</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2145
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2146</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2147
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2148<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2149<h4>
2150 <a name="t_vector">Vector Type</a>
2151</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2152
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2153<div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2154
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2155<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2156<p>A vector type is a simple derived type that represents a vector of elements.
2157 Vector types are used when multiple primitive data are operated in parallel
2158 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]2159 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2160 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2161
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2162<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2163<pre>
2164 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2165</pre>
2166
Chris Lattnerf11031a2010-10-10 18:20:35 +0000[diff] [blame]2167<p>The number of elements is a constant integer value larger than 0; elementtype
2168 may be any integer or floating point type. Vectors of size zero are not
2169 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2170
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2171<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2172<table class="layout">
2173 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2174 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
2175 <td class="left">Vector of 4 32-bit integer values.</td>
2176 </tr>
2177 <tr class="layout">
2178 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
2179 <td class="left">Vector of 8 32-bit floating-point values.</td>
2180 </tr>
2181 <tr class="layout">
2182 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2183 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2184 </tr>
2185</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2186
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2187</div>
2188
Bill Wendlingae8b5ea2011-07-31 06:47:33 +0000[diff] [blame]2189</div>
2190
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2191<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2192<h2><a name="constants">Constants</a></h2>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2193<!-- *********************************************************************** -->
2194
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2195<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2196
2197<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2198 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2199
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2200<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2201<h3>
2202 <a name="simpleconstants">Simple Constants</a>
2203</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2204
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2205<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2206
2207<dl>
2208 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2209 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]2210 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2211
2212 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2213 <dd>Standard integers (such as '4') are constants of
2214 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2215 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2216
2217 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2218 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2219 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2220 notation (see below). The assembler requires the exact decimal value of a
2221 floating-point constant. For example, the assembler accepts 1.25 but
2222 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2223 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2224
2225 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2226 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2227 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2228</dl>
2229
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2230<p>The one non-intuitive notation for constants is the hexadecimal form of
2231 floating point constants. For example, the form '<tt>double
2232 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2233 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2234 constants are required (and the only time that they are generated by the
2235 disassembler) is when a floating point constant must be emitted but it cannot
2236 be represented as a decimal floating point number in a reasonable number of
2237 digits. For example, NaN's, infinities, and other special values are
2238 represented in their IEEE hexadecimal format so that assembly and disassembly
2239 do not cause any bits to change in the constants.</p>
2240
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]2241<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2242 represented using the 16-digit form shown above (which matches the IEEE754
2243 representation for double); float values must, however, be exactly
2244 representable as IEE754 single precision. Hexadecimal format is always used
2245 for long double, and there are three forms of long double. The 80-bit format
2246 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2247 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2248 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2249 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2250 currently supported target uses this format. Long doubles will only work if
2251 they match the long double format on your target. All hexadecimal formats
2252 are big-endian (sign bit at the left).</p>
2253
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]2254<p>There are no constants of type x86mmx.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2255</div>
2256
2257<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2258<h3>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2259<a name="aggregateconstants"></a> <!-- old anchor -->
2260<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2261</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2262
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2263<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2264
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2265<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2266 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2267
2268<dl>
2269 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2270 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2271 type definitions (a comma separated list of elements, surrounded by braces
2272 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2273 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2274 Structure constants must have <a href="#t_struct">structure type</a>, and
2275 the number and types of elements must match those specified by the
2276 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2277
2278 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2279 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2280 definitions (a comma separated list of elements, surrounded by square
2281 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2282 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2283 the number and types of elements must match those specified by the
2284 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2285
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2286 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2287 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2288 definitions (a comma separated list of elements, surrounded by
2289 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2290 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2291 have <a href="#t_vector">vector type</a>, and the number and types of
2292 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2293
2294 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2295 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2296 value to zero of <em>any</em> type, including scalar and
2297 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2298 This is often used to avoid having to print large zero initializers
2299 (e.g. for large arrays) and is always exactly equivalent to using explicit
2300 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2301
2302 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2303 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2304 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2305 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2306 be interpreted as part of the instruction stream, metadata is a place to
2307 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2308</dl>
2309
2310</div>
2311
2312<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2313<h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2314 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2315</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2316
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2317<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2318
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2319<p>The addresses of <a href="#globalvars">global variables</a>
2320 and <a href="#functionstructure">functions</a> are always implicitly valid
2321 (link-time) constants. These constants are explicitly referenced when
2322 the <a href="#identifiers">identifier for the global</a> is used and always
2323 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2324 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2325
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2326<pre class="doc_code">
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2327@X = global i32 17
2328@Y = global i32 42
2329@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2330</pre>
2331
2332</div>
2333
2334<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2335<h3>
2336 <a name="undefvalues">Undefined Values</a>
2337</h3>
2338
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2339<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2340
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2341<p>The string '<tt>undef</tt>' can be used anywhere a constant is expected, and
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2342 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2343 Undefined values may be of any type (other than '<tt>label</tt>'
2344 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2345
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2346<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2347 program is well defined no matter what value is used. This gives the
2348 compiler more freedom to optimize. Here are some examples of (potentially
2349 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2350
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2351
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2352<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2353 %A = add %X, undef
2354 %B = sub %X, undef
2355 %C = xor %X, undef
2356Safe:
2357 %A = undef
2358 %B = undef
2359 %C = undef
2360</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2361
2362<p>This is safe because all of the output bits are affected by the undef bits.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2363 Any output bit can have a zero or one depending on the input bits.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2364
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2365<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2366 %A = or %X, undef
2367 %B = and %X, undef
2368Safe:
2369 %A = -1
2370 %B = 0
2371Unsafe:
2372 %A = undef
2373 %B = undef
2374</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2375
2376<p>These logical operations have bits that are not always affected by the input.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2377 For example, if <tt>%X</tt> has a zero bit, then the output of the
2378 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2379 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2380 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2381 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2382 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2383 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2384 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2385
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2386<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2387 %A = select undef, %X, %Y
2388 %B = select undef, 42, %Y
2389 %C = select %X, %Y, undef
2390Safe:
2391 %A = %X (or %Y)
2392 %B = 42 (or %Y)
2393 %C = %Y
2394Unsafe:
2395 %A = undef
2396 %B = undef
2397 %C = undef
2398</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2399
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2400<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2401 branch) conditions can go <em>either way</em>, but they have to come from one
2402 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2403 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2404 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2405 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2406 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2407 eliminated.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2408
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2409<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2410 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2411
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2412 %B = undef
2413 %C = xor %B, %B
2414
2415 %D = undef
2416 %E = icmp lt %D, 4
2417 %F = icmp gte %D, 4
2418
2419Safe:
2420 %A = undef
2421 %B = undef
2422 %C = undef
2423 %D = undef
2424 %E = undef
2425 %F = undef
2426</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2427
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2428<p>This example points out that two '<tt>undef</tt>' operands are not
2429 necessarily the same. This can be surprising to people (and also matches C
2430 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2431 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2432 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2433 its value over its "live range". This is true because the variable doesn't
2434 actually <em>have a live range</em>. Instead, the value is logically read
2435 from arbitrary registers that happen to be around when needed, so the value
2436 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2437 need to have the same semantics or the core LLVM "replace all uses with"
2438 concept would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2439
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2440<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2441 %A = fdiv undef, %X
2442 %B = fdiv %X, undef
2443Safe:
2444 %A = undef
2445b: unreachable
2446</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2447
2448<p>These examples show the crucial difference between an <em>undefined
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2449 value</em> and <em>undefined behavior</em>. An undefined value (like
2450 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2451 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2452 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2453 defined on SNaN's. However, in the second example, we can make a more
2454 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2455 arbitrary value, we are allowed to assume that it could be zero. Since a
2456 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2457 the operation does not execute at all. This allows us to delete the divide and
2458 all code after it. Because the undefined operation "can't happen", the
2459 optimizer can assume that it occurs in dead code.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2460
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2461<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2462a: store undef -> %X
2463b: store %X -> undef
2464Safe:
2465a: &lt;deleted&gt;
2466b: unreachable
2467</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2468
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2469<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2470 undefined value can be assumed to not have any effect; we can assume that the
2471 value is overwritten with bits that happen to match what was already there.
2472 However, a store <em>to</em> an undefined location could clobber arbitrary
2473 memory, therefore, it has undefined behavior.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2474
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2475</div>
2476
2477<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2478<h3>
2479 <a name="trapvalues">Trap Values</a>
2480</h3>
2481
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2482<div>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2483
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2484<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2485 instead of representing an unspecified bit pattern, they represent the
2486 fact that an instruction or constant expression which cannot evoke side
2487 effects has nevertheless detected a condition which results in undefined
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2488 behavior.</p>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2489
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2490<p>There is currently no way of representing a trap value in the IR; they
Dan Gohmanac355aa2010-05-03 14:51:43 +0000[diff] [blame]2491 only exist when produced by operations such as
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2492 <a href="#i_add"><tt>add</tt></a> with the <tt>nsw</tt> flag.</p>
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2493
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2494<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2495
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2496<ul>
2497<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2498 their operands.</li>
2499
2500<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2501 to their dynamic predecessor basic block.</li>
2502
2503<li>Function arguments depend on the corresponding actual argument values in
2504 the dynamic callers of their functions.</li>
2505
2506<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2507 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2508 control back to them.</li>
2509
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2510<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2511 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2512 or exception-throwing call instructions that dynamically transfer control
2513 back to them.</li>
2514
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2515<li>Non-volatile loads and stores depend on the most recent stores to all of the
2516 referenced memory addresses, following the order in the IR
2517 (including loads and stores implied by intrinsics such as
2518 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2519
Dan Gohman3513ea52010-05-03 14:59:34 +0000[diff] [blame]2520<!-- TODO: In the case of multiple threads, this only applies if the store
2521 "happens-before" the load or store. -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2522
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2523<!-- TODO: floating-point exception state -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2524
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2525<li>An instruction with externally visible side effects depends on the most
2526 recent preceding instruction with externally visible side effects, following
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]2527 the order in the IR. (This includes
2528 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2529
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2530<li>An instruction <i>control-depends</i> on a
2531 <a href="#terminators">terminator instruction</a>
2532 if the terminator instruction has multiple successors and the instruction
2533 is always executed when control transfers to one of the successors, and
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2534 may not be executed when control is transferred to another.</li>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2535
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2536<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2537 instruction if the set of instructions it otherwise depends on would be
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2538 different if the terminator had transferred control to a different
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2539 successor.</li>
2540
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2541<li>Dependence is transitive.</li>
2542
2543</ul>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2544
2545<p>Whenever a trap value is generated, all values which depend on it evaluate
2546 to trap. If they have side effects, the evoke their side effects as if each
2547 operand with a trap value were undef. If they have externally-visible side
2548 effects, the behavior is undefined.</p>
2549
2550<p>Here are some examples:</p>
Dan Gohman48a25882010-04-26 20:54:53 +0000[diff] [blame]2551
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2552<pre class="doc_code">
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2553entry:
2554 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2555 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2556 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2557 store i32 0, i32* %trap_yet_again ; undefined behavior
2558
2559 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2560 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2561
2562 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2563
2564 %narrowaddr = bitcast i32* @g to i16*
2565 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2566 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2567 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2568
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2569 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2570 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2571
2572true:
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2573 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2574 ; it has undefined behavior.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2575 br label %end
2576
2577end:
2578 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2579 ; Both edges into this PHI are
2580 ; control-dependent on %cmp, so this
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2581 ; always results in a trap value.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2582
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2583 volatile store i32 0, i32* @g ; This would depend on the store in %true
2584 ; if %cmp is true, or the store in %entry
2585 ; otherwise, so this is undefined behavior.
2586
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2587 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2588 ; The same branch again, but this time the
2589 ; true block doesn't have side effects.
2590
2591second_true:
2592 ; No side effects!
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2593 ret void
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2594
2595second_end:
2596 volatile store i32 0, i32* @g ; This time, the instruction always depends
2597 ; on the store in %end. Also, it is
2598 ; control-equivalent to %end, so this is
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2599 ; well-defined (again, ignoring earlier
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2600 ; undefined behavior in this example).
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2601</pre>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2602
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2603</div>
2604
2605<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2606<h3>
2607 <a name="blockaddress">Addresses of Basic Blocks</a>
2608</h3>
2609
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2610<div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2611
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2612<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2613
2614<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2615 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2616 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2617
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2618<p>This value only has defined behavior when used as an operand to the
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2619 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2620 comparisons against null. Pointer equality tests between labels addresses
2621 results in undefined behavior &mdash; though, again, comparison against null
2622 is ok, and no label is equal to the null pointer. This may be passed around
2623 as an opaque pointer sized value as long as the bits are not inspected. This
2624 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2625 long as the original value is reconstituted before the <tt>indirectbr</tt>
2626 instruction.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2627
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2628<p>Finally, some targets may provide defined semantics when using the value as
2629 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2630
2631</div>
2632
2633
2634<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2635<h3>
2636 <a name="constantexprs">Constant Expressions</a>
2637</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2638
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2639<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2640
2641<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2642 to be used as constants. Constant expressions may be of
2643 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2644 operation that does not have side effects (e.g. load and call are not
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2645 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2646
2647<dl>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2648 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2649 <dd>Truncate a constant to another type. The bit size of CST must be larger
2650 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2651
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2652 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2653 <dd>Zero extend a constant to another type. The bit size of CST must be
Duncan Sandsa522e562010-07-13 12:06:14 +0000[diff] [blame]2654 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2655
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2656 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2657 <dd>Sign extend a constant to another type. The bit size of CST must be
Duncan Sandsa522e562010-07-13 12:06:14 +0000[diff] [blame]2658 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2659
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2660 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2661 <dd>Truncate a floating point constant to another floating point type. The
2662 size of CST must be larger than the size of TYPE. Both types must be
2663 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2664
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2665 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2666 <dd>Floating point extend a constant to another type. The size of CST must be
2667 smaller or equal to the size of TYPE. Both types must be floating
2668 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2669
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2670 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2671 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2672 constant. TYPE must be a scalar or vector integer type. CST must be of
2673 scalar or vector floating point type. Both CST and TYPE must be scalars,
2674 or vectors of the same number of elements. If the value won't fit in the
2675 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2676
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2677 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2678 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2679 constant. TYPE must be a scalar or vector integer type. CST must be of
2680 scalar or vector floating point type. Both CST and TYPE must be scalars,
2681 or vectors of the same number of elements. If the value won't fit in the
2682 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2683
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2684 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2685 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2686 constant. TYPE must be a scalar or vector floating point type. CST must be
2687 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2688 vectors of the same number of elements. If the value won't fit in the
2689 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2690
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2691 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2692 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2693 constant. TYPE must be a scalar or vector floating point type. CST must be
2694 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2695 vectors of the same number of elements. If the value won't fit in the
2696 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2697
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2698 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2699 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2700 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2701 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2702 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2703
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2704 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2705 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2706 type. CST must be of integer type. The CST value is zero extended,
2707 truncated, or unchanged to make it fit in a pointer size. This one is
2708 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2709
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2710 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2711 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2712 are the same as those for the <a href="#i_bitcast">bitcast
2713 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2714
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2715 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2716 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2717 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2718 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2719 instruction, the index list may have zero or more indexes, which are
2720 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2721
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2722 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2723 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2724
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2725 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2726 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2727
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2728 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2729 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2730
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2731 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2732 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2733 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2734
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2735 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2736 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2737 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2738
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2739 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2740 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2741 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2742
Nick Lewycky9ab9a7f2010-05-29 06:44:15 +0000[diff] [blame]2743 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2744 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2745 constants. The index list is interpreted in a similar manner as indices in
2746 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2747 index value must be specified.</dd>
2748
2749 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2750 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2751 constants. The index list is interpreted in a similar manner as indices in
2752 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2753 index value must be specified.</dd>
2754
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2755 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2756 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2757 be any of the <a href="#binaryops">binary</a>
2758 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2759 on operands are the same as those for the corresponding instruction
2760 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2761</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2762
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2763</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2764
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2765</div>
2766
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2767<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2768<h2><a name="othervalues">Other Values</a></h2>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2769<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2770<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2771<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2772<h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2773<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2774</h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2775
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2776<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2777
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2778<p>LLVM supports inline assembler expressions (as opposed
2779 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2780 a special value. This value represents the inline assembler as a string
2781 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2782 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2783 expression has side effects, and a flag indicating whether the function
2784 containing the asm needs to align its stack conservatively. An example
2785 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2786
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2787<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2788i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2789</pre>
2790
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2791<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2792 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2793 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2794
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2795<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2796%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]2797</pre>
2798
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2799<p>Inline asms with side effects not visible in the constraint list must be
2800 marked as having side effects. This is done through the use of the
2801 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2802
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2803<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2804call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2805</pre>
2806
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2807<p>In some cases inline asms will contain code that will not work unless the
2808 stack is aligned in some way, such as calls or SSE instructions on x86,
2809 yet will not contain code that does that alignment within the asm.
2810 The compiler should make conservative assumptions about what the asm might
2811 contain and should generate its usual stack alignment code in the prologue
2812 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2813
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2814<pre class="doc_code">
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2815call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2816</pre>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2817
2818<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2819 first.</p>
2820
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2821<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2822 documented here. Constraints on what can be done (e.g. duplication, moving,
2823 etc need to be documented). This is probably best done by reference to
2824 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2825
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2826<h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2827<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2828</h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2829
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2830<div>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2831
2832<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattner79ffdc72010-11-17 08:20:42 +0000[diff] [blame]2833 attached to it that contains a list of constant integers. If present, the
2834 code generator will use the integer as the location cookie value when report
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2835 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]2836 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2837 source code that produced it. For example:</p>
2838
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2839<pre class="doc_code">
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2840call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2841...
2842!42 = !{ i32 1234567 }
2843</pre>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2844
2845<p>It is up to the front-end to make sense of the magic numbers it places in the
Chris Lattner79ffdc72010-11-17 08:20:42 +0000[diff] [blame]2846 IR. If the MDNode contains multiple constants, the code generator will use
2847 the one that corresponds to the line of the asm that the error occurs on.</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2848
2849</div>
2850
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2851</div>
2852
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2853<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2854<h3>
2855 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2856</h3>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2857
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2858<div>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2859
2860<p>LLVM IR allows metadata to be attached to instructions in the program that
2861 can convey extra information about the code to the optimizers and code
2862 generator. One example application of metadata is source-level debug
2863 information. There are two metadata primitives: strings and nodes. All
2864 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2865 preceding exclamation point ('<tt>!</tt>').</p>
2866
2867<p>A metadata string is a string surrounded by double quotes. It can contain
2868 any character by escaping non-printable characters with "\xx" where "xx" is
2869 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2870
2871<p>Metadata nodes are represented with notation similar to structure constants
2872 (a comma separated list of elements, surrounded by braces and preceded by an
2873 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2874 10}</tt>". Metadata nodes can have any values as their operand.</p>
2875
2876<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2877 metadata nodes, which can be looked up in the module symbol table. For
2878 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2879
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2880<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2881 function is using two metadata arguments.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2882
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2883<div class="doc_code">
2884<pre>
2885call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2886</pre>
2887</div>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2888
2889<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2890 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2891
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2892<div class="doc_code">
2893<pre>
2894%indvar.next = add i64 %indvar, 1, !dbg !21
2895</pre>
2896</div>
2897
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2898</div>
2899
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2900</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2901
2902<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2903<h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2904 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2905</h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2906<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2907<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2908<p>LLVM has a number of "magic" global variables that contain data that affect
2909code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2910of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2911section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2912by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2913
2914<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2915<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2916<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2917</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2918
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2919<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2920
2921<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2922href="#linkage_appending">appending linkage</a>. This array contains a list of
2923pointers to global variables and functions which may optionally have a pointer
2924cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2925
2926<pre>
2927 @X = global i8 4
2928 @Y = global i32 123
2929
2930 @llvm.used = appending global [2 x i8*] [
2931 i8* @X,
2932 i8* bitcast (i32* @Y to i8*)
2933 ], section "llvm.metadata"
2934</pre>
2935
2936<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2937compiler, assembler, and linker are required to treat the symbol as if there is
2938a reference to the global that it cannot see. For example, if a variable has
2939internal linkage and no references other than that from the <tt>@llvm.used</tt>
2940list, it cannot be deleted. This is commonly used to represent references from
2941inline asms and other things the compiler cannot "see", and corresponds to
2942"attribute((used))" in GNU C.</p>
2943
2944<p>On some targets, the code generator must emit a directive to the assembler or
2945object file to prevent the assembler and linker from molesting the symbol.</p>
2946
2947</div>
2948
2949<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2950<h3>
2951 <a name="intg_compiler_used">
2952 The '<tt>llvm.compiler.used</tt>' Global Variable
2953 </a>
2954</h3>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2955
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2956<div>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2957
2958<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2959<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2960touching the symbol. On targets that support it, this allows an intelligent
2961linker to optimize references to the symbol without being impeded as it would be
2962by <tt>@llvm.used</tt>.</p>
2963
2964<p>This is a rare construct that should only be used in rare circumstances, and
2965should not be exposed to source languages.</p>
2966
2967</div>
2968
2969<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2970<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2971<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2972</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2973
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2974<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2975<pre>
2976%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2977@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2978</pre>
2979<p>The <tt>@llvm.global_ctors</tt> array contains a list of constructor functions and associated priorities. The functions referenced by this array will be called in ascending order of priority (i.e. lowest first) when the module is loaded. The order of functions with the same priority is not defined.
2980</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2981
2982</div>
2983
2984<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2985<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2986<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2987</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2988
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2989<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2990<pre>
2991%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2992@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2993</pre>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2994
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2995<p>The <tt>@llvm.global_dtors</tt> array contains a list of destructor functions and associated priorities. The functions referenced by this array will be called in descending order of priority (i.e. highest first) when the module is loaded. The order of functions with the same priority is not defined.
2996</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2997
2998</div>
2999
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3000</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]3001
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]3002<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3003<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3004<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3005
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3006<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3007
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3008<p>The LLVM instruction set consists of several different classifications of
3009 instructions: <a href="#terminators">terminator
3010 instructions</a>, <a href="#binaryops">binary instructions</a>,
3011 <a href="#bitwiseops">bitwise binary instructions</a>,
3012 <a href="#memoryops">memory instructions</a>, and
3013 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3014
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3015<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3016<h3>
3017 <a name="terminators">Terminator Instructions</a>
3018</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3019
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3020<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3021
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3022<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
3023 in a program ends with a "Terminator" instruction, which indicates which
3024 block should be executed after the current block is finished. These
3025 terminator instructions typically yield a '<tt>void</tt>' value: they produce
3026 control flow, not values (the one exception being the
3027 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
3028
Bill Wendlingf891bf82011-07-31 06:30:59 +0000[diff] [blame]3029<p>There are eight different terminator instructions: the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3030 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
3031 '<a href="#i_br"><tt>br</tt></a>' instruction, the
3032 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling33fef7e2009-11-02 00:25:26 +0000[diff] [blame]3033 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3034 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
Bill Wendlingf891bf82011-07-31 06:30:59 +0000[diff] [blame]3035 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, the
3036 '<a href="#i_resume"><tt>resume</tt></a>' instruction, and the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3037 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]3038
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3039<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3040<h4>
3041 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
3042</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3043
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3044<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3045
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3046<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]3047<pre>
3048 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]3049 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3050</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3051
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3052<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3053<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
3054 a value) from a function back to the caller.</p>
3055
3056<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
3057 value and then causes control flow, and one that just causes control flow to
3058 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3059
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3060<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3061<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
3062 return value. The type of the return value must be a
3063 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]3064
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3065<p>A function is not <a href="#wellformed">well formed</a> if it it has a
3066 non-void return type and contains a '<tt>ret</tt>' instruction with no return
3067 value or a return value with a type that does not match its type, or if it
3068 has a void return type and contains a '<tt>ret</tt>' instruction with a
3069 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3070
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3071<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3072<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
3073 the calling function's context. If the caller is a
3074 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
3075 instruction after the call. If the caller was an
3076 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
3077 the beginning of the "normal" destination block. If the instruction returns
3078 a value, that value shall set the call or invoke instruction's return
3079 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3080
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3081<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]3082<pre>
3083 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3084 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]3085 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]3086</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]3087
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3088</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3089<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3090<h4>
3091 <a name="i_br">'<tt>br</tt>' Instruction</a>
3092</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3093
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3094<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3095
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3096<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3097<pre>
Bill Wendling16b86742011-07-26 10:41:15 +0000[diff] [blame]3098 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;
3099 br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3100</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3101
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3102<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3103<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3104 different basic block in the current function. There are two forms of this
3105 instruction, corresponding to a conditional branch and an unconditional
3106 branch.</p>
3107
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3108<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3109<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3110 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3111 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3112 target.</p>
3113
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3114<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3115<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3116 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3117 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3118 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3119
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3120<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]3121<pre>
3122Test:
3123 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3124 br i1 %cond, label %IfEqual, label %IfUnequal
3125IfEqual:
3126 <a href="#i_ret">ret</a> i32 1
3127IfUnequal:
3128 <a href="#i_ret">ret</a> i32 0
3129</pre>
3130
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3131</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3132
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3133<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3134<h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3135 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3136</h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3137
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3138<div>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3139
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3140<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3141<pre>
3142 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3143</pre>
3144
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3145<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3146<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]3147 several different places. It is a generalization of the '<tt>br</tt>'
3148 instruction, allowing a branch to occur to one of many possible
3149 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3150
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3151<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3152<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3153 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3154 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3155 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3156
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3157<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3158<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3159 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3160 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]3161 transferred to the corresponding destination; otherwise, control flow is
3162 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3163
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3164<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3165<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3166 <tt>switch</tt> instruction, this instruction may be code generated in
3167 different ways. For example, it could be generated as a series of chained
3168 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3169
3170<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3171<pre>
3172 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3173 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3174 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3175
3176 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3177 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3178
3179 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3180 switch i32 %val, label %otherwise [ i32 0, label %onzero
3181 i32 1, label %onone
3182 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3183</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3184
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3185</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3186
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3187
3188<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3189<h4>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3190 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3191</h4>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3192
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3193<div>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3194
3195<h5>Syntax:</h5>
3196<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3197 indirectbr &lt;somety&gt;* &lt;address&gt;, [ label &lt;dest1&gt;, label &lt;dest2&gt;, ... ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3198</pre>
3199
3200<h5>Overview:</h5>
3201
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3202<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3203 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]3204 "<tt>address</tt>". Address must be derived from a <a
3205 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3206
3207<h5>Arguments:</h5>
3208
3209<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3210 rest of the arguments indicate the full set of possible destinations that the
3211 address may point to. Blocks are allowed to occur multiple times in the
3212 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3213
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3214<p>This destination list is required so that dataflow analysis has an accurate
3215 understanding of the CFG.</p>
3216
3217<h5>Semantics:</h5>
3218
3219<p>Control transfers to the block specified in the address argument. All
3220 possible destination blocks must be listed in the label list, otherwise this
3221 instruction has undefined behavior. This implies that jumps to labels
3222 defined in other functions have undefined behavior as well.</p>
3223
3224<h5>Implementation:</h5>
3225
3226<p>This is typically implemented with a jump through a register.</p>
3227
3228<h5>Example:</h5>
3229<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3230 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3231</pre>
3232
3233</div>
3234
3235
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3236<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3237<h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3238 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3239</h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3240
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3241<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3242
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3243<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3244<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3245 &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]3246 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3247</pre>
3248
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3249<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3250<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3251 function, with the possibility of control flow transfer to either the
3252 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3253 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3254 control flow will return to the "normal" label. If the callee (or any
3255 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3256 instruction, control is interrupted and continued at the dynamically nearest
3257 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3258
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3259<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3260<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3261
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3262<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3263 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3264 convention</a> the call should use. If none is specified, the call
3265 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3266
3267 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3268 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3269 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3270
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3271 <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]3272 function value being invoked. In most cases, this is a direct function
3273 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3274 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3275
3276 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3277 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3278
3279 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]3280 signature argument types and parameter attributes. All arguments must be
3281 of <a href="#t_firstclass">first class</a> type. If the function
3282 signature indicates the function accepts a variable number of arguments,
3283 the extra arguments can be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3284
3285 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3286 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3287
3288 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3289 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3290
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3291 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3292 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3293 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3294</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3295
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3296<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3297<p>This instruction is designed to operate as a standard
3298 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3299 primary difference is that it establishes an association with a label, which
3300 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3301
3302<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3303 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3304 exception. Additionally, this is important for implementation of
3305 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3306
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3307<p>For the purposes of the SSA form, the definition of the value returned by the
3308 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3309 block to the "normal" label. If the callee unwinds then no return value is
3310 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]3311
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3312<p>Note that the code generator does not yet completely support unwind, and
3313that the invoke/unwind semantics are likely to change in future versions.</p>
3314
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3315<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3316<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3317 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3318 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3319 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3320 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3321</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3322
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3323</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3324
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3325<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3326
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3327<h4>
3328 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3329</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3330
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3331<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3332
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3333<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3334<pre>
3335 unwind
3336</pre>
3337
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3338<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3339<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3340 at the first callee in the dynamic call stack which used
3341 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3342 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3343
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3344<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3345<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3346 immediately halt. The dynamic call stack is then searched for the
3347 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3348 Once found, execution continues at the "exceptional" destination block
3349 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3350 instruction in the dynamic call chain, undefined behavior results.</p>
3351
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3352<p>Note that the code generator does not yet completely support unwind, and
3353that the invoke/unwind semantics are likely to change in future versions.</p>
3354
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3355</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3356
Bill Wendlingf891bf82011-07-31 06:30:59 +0000[diff] [blame]3357 <!-- _______________________________________________________________________ -->
3358
3359<h4>
3360 <a name="i_resume">'<tt>resume</tt>' Instruction</a>
3361</h4>
3362
3363<div>
3364
3365<h5>Syntax:</h5>
3366<pre>
3367 resume &lt;type&gt; &lt;value&gt;
3368</pre>
3369
3370<h5>Overview:</h5>
3371<p>The '<tt>resume</tt>' instruction is a terminator instruction that has no
3372 successors.</p>
3373
3374<h5>Arguments:</h5>
3375<p>The '<tt>resume</tt>' instruction's argument must have the same type as the
3376 result of any '<tt>landingpad</tt>' instruction in the same function.</p>
3377
3378<h5>Semantics:</h5>
3379<p>The '<tt>resume</tt>' instruction resumes propagation of an existing
3380 (in-flight) exception whose unwinding was interrupted with
3381 a landingpad instruction.</p>
3382
3383<h5>Example:</h5>
3384<pre>
3385 resume { i8*, i32 } %exn
3386</pre>
3387
3388</div>
3389
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3390<!-- _______________________________________________________________________ -->
3391
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3392<h4>
3393 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3394</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3395
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3396<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3397
3398<h5>Syntax:</h5>
3399<pre>
3400 unreachable
3401</pre>
3402
3403<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3404<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3405 instruction is used to inform the optimizer that a particular portion of the
3406 code is not reachable. This can be used to indicate that the code after a
3407 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3408
3409<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3410<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3411
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3412</div>
3413
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3414</div>
3415
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3416<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3417<h3>
3418 <a name="binaryops">Binary Operations</a>
3419</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3420
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3421<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3422
3423<p>Binary operators are used to do most of the computation in a program. They
3424 require two operands of the same type, execute an operation on them, and
3425 produce a single value. The operands might represent multiple data, as is
3426 the case with the <a href="#t_vector">vector</a> data type. The result value
3427 has the same type as its operands.</p>
3428
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3429<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3430
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3431<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3432<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3433 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3434</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3435
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3436<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3437
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3438<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3439<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3440 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3441 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3442 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3443 &lt;result&gt; = add nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3444</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3445
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3446<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3447<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3448
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3449<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3450<p>The two arguments to the '<tt>add</tt>' instruction must
3451 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3452 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3453
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3454<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3455<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3456
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3457<p>If the sum has unsigned overflow, the result returned is the mathematical
3458 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]3459
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3460<p>Because LLVM integers use a two's complement representation, this instruction
3461 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3462
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3463<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3464 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3465 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3466 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3467 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3468
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3469<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3470<pre>
3471 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3472</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3473
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3474</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3475
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3476<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3477<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3478 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3479</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3480
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3481<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3482
3483<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3484<pre>
3485 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3486</pre>
3487
3488<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3489<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3490
3491<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3492<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3493 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3494 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3495
3496<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3497<p>The value produced is the floating point sum of the two operands.</p>
3498
3499<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3500<pre>
3501 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3502</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3503
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3504</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3505
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3506<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3507<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3508 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3509</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3510
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3511<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3512
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3513<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3514<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3515 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3516 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3517 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3518 &lt;result&gt; = sub nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3519</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3520
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3521<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3522<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3523 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3524
3525<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3526 '<tt>neg</tt>' instruction present in most other intermediate
3527 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3528
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3529<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3530<p>The two arguments to the '<tt>sub</tt>' instruction must
3531 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3532 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3533
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3534<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3535<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3536
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3537<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3538 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3539 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3540
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3541<p>Because LLVM integers use a two's complement representation, this instruction
3542 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3543
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3544<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3545 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3546 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3547 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3548 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3549
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3550<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3551<pre>
3552 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3553 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3554</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3555
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3556</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3557
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3558<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3559<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3560 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3561</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3562
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3563<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3564
3565<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3566<pre>
3567 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3568</pre>
3569
3570<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3571<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3572 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3573
3574<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3575 '<tt>fneg</tt>' instruction present in most other intermediate
3576 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3577
3578<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3579<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3580 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3581 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3582
3583<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3584<p>The value produced is the floating point difference of the two operands.</p>
3585
3586<h5>Example:</h5>
3587<pre>
3588 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3589 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3590</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3591
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3592</div>
3593
3594<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3595<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3596 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3597</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3598
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3599<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3600
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3601<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3602<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3603 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3604 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3605 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3606 &lt;result&gt; = mul nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3607</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3608
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3609<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3610<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3611
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3612<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3613<p>The two arguments to the '<tt>mul</tt>' instruction must
3614 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3615 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3616
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3617<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3618<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3619
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3620<p>If the result of the multiplication has unsigned overflow, the result
3621 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3622 width of the result.</p>
3623
3624<p>Because LLVM integers use a two's complement representation, and the result
3625 is the same width as the operands, this instruction returns the correct
3626 result for both signed and unsigned integers. If a full product
3627 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3628 be sign-extended or zero-extended as appropriate to the width of the full
3629 product.</p>
3630
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3631<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3632 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3633 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3634 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3635 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3636
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3637<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3638<pre>
3639 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3640</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3641
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3642</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3643
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3644<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3645<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3646 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3647</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3648
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3649<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3650
3651<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3652<pre>
3653 &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]3654</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3655
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3656<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3657<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3658
3659<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3660<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3661 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3662 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3663
3664<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3665<p>The value produced is the floating point product of the two operands.</p>
3666
3667<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3668<pre>
3669 &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]3670</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3671
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3672</div>
3673
3674<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3675<h4>
3676 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3677</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3678
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3679<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3680
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3681<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3682<pre>
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3683 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3684 &lt;result&gt; = udiv exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3685</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3686
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3687<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3688<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3689
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3690<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3691<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3692 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3693 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3694
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3695<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3696<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3697
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3698<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3699 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3700
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3701<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3702
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3703<p>If the <tt>exact</tt> keyword is present, the result value of the
3704 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3705 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3706
3707
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3708<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3709<pre>
3710 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3711</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3712
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3713</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3714
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3715<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3716<h4>
3717 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3718</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3719
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3720<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3721
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3722<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3723<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3724 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3725 &lt;result&gt; = sdiv exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3726</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3727
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3728<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3729<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3730
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3731<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3732<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3733 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3734 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3735
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3736<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3737<p>The value produced is the signed integer quotient of the two operands rounded
3738 towards zero.</p>
3739
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3740<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3741 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3742
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3743<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3744 undefined behavior; this is a rare case, but can occur, for example, by doing
3745 a 32-bit division of -2147483648 by -1.</p>
3746
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3747<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]3748 <tt>sdiv</tt> is a <a href="#trapvalues">trap value</a> if the result would
Dan Gohmane501ff72010-07-11 00:08:34 +0000[diff] [blame]3749 be rounded.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3750
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3751<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3752<pre>
3753 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3754</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3755
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3756</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3757
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3758<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3759<h4>
3760 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3761</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3762
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3763<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3764
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3765<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3766<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3767 &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]3768</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3769
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3770<h5>Overview:</h5>
3771<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3772
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3773<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3774<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3775 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3776 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3777
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3778<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3779<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3780
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3781<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3782<pre>
3783 &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]3784</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3785
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3786</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3787
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3788<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3789<h4>
3790 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3791</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3792
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3793<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3794
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3795<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3796<pre>
3797 &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]3798</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3799
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3800<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3801<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3802 division of its two arguments.</p>
3803
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3804<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3805<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3806 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3807 values. Both arguments must have identical types.</p>
3808
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3809<h5>Semantics:</h5>
3810<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3811 This instruction always performs an unsigned division to get the
3812 remainder.</p>
3813
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3814<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3815 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3816
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3817<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3818
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3819<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3820<pre>
3821 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3822</pre>
3823
3824</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3825
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3826<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3827<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3828 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3829</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3830
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3831<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3832
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3833<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3834<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3835 &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]3836</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3837
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3838<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3839<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3840 division of its two operands. This instruction can also take
3841 <a href="#t_vector">vector</a> versions of the values in which case the
3842 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3843
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3844<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3845<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3846 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3847 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3848
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3849<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3850<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sands2769c6e2011-03-07 09:12:24 +0000[diff] [blame]3851 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3852 <i>modulo</i> operator (where the result is either zero or has the same sign
3853 as the divisor, <tt>op2</tt>) of a value.
3854 For more information about the difference,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3855 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3856 Math Forum</a>. For a table of how this is implemented in various languages,
3857 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3858 Wikipedia: modulo operation</a>.</p>
3859
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3860<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3861 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3862
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3863<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3864 Overflow also leads to undefined behavior; this is a rare case, but can
3865 occur, for example, by taking the remainder of a 32-bit division of
3866 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3867 lets srem be implemented using instructions that return both the result of
3868 the division and the remainder.)</p>
3869
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3870<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3871<pre>
3872 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3873</pre>
3874
3875</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3876
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3877<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3878<h4>
3879 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3880</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3881
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3882<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3883
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3884<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3885<pre>
3886 &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]3887</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3888
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3889<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3890<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3891 its two operands.</p>
3892
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3893<h5>Arguments:</h5>
3894<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3895 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3896 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3897
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3898<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3899<p>This instruction returns the <i>remainder</i> of a division. The remainder
3900 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3901
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3902<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3903<pre>
3904 &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]3905</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3906
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3907</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3908
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3909</div>
3910
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3911<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3912<h3>
3913 <a name="bitwiseops">Bitwise Binary Operations</a>
3914</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3915
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3916<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3917
3918<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3919 program. They are generally very efficient instructions and can commonly be
3920 strength reduced from other instructions. They require two operands of the
3921 same type, execute an operation on them, and produce a single value. The
3922 resulting value is the same type as its operands.</p>
3923
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3924<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3925<h4>
3926 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3927</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3928
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3929<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3930
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3931<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3932<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3933 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3934 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3935 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3936 &lt;result&gt; = shl nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3937</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3938
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3939<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3940<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3941 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3942
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3943<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3944<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3945 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3946 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3947
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3948<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3949<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3950 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3951 is (statically or dynamically) negative or equal to or larger than the number
3952 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3953 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3954 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3955
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3956<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3957 <a href="#trapvalues">trap value</a> if it shifts out any non-zero bits. If
Chris Lattnerf10dfdc2011-02-09 16:44:44 +0000[diff] [blame]3958 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3959 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3960 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3961 they would if the shift were expressed as a mul instruction with the same
3962 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3963
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3964<h5>Example:</h5>
3965<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3966 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3967 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3968 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3969 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3970 &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]3971</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3972
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3973</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3974
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3975<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3976<h4>
3977 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3978</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3979
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3980<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3981
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3982<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3983<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3984 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3985 &lt;result&gt; = lshr exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3986</pre>
3987
3988<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3989<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3990 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3991
3992<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3993<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3994 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3995 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3996
3997<h5>Semantics:</h5>
3998<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3999 significant bits of the result will be filled with zero bits after the shift.
4000 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
4001 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
4002 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
4003 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4004
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4005<p>If the <tt>exact</tt> keyword is present, the result value of the
4006 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4007 shifted out are non-zero.</p>
4008
4009
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4010<h5>Example:</h5>
4011<pre>
4012 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
4013 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
4014 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
4015 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]4016 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]4017 &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]4018</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4019
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4020</div>
4021
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]4022<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4023<h4>
4024 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
4025</h4>
4026
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4027<div>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4028
4029<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4030<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4031 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4032 &lt;result&gt; = ashr exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4033</pre>
4034
4035<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4036<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
4037 operand shifted to the right a specified number of bits with sign
4038 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4039
4040<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4041<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4042 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4043 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4044
4045<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4046<p>This instruction always performs an arithmetic shift right operation, The
4047 most significant bits of the result will be filled with the sign bit
4048 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
4049 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
4050 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
4051 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4052
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]4053<p>If the <tt>exact</tt> keyword is present, the result value of the
4054 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4055 shifted out are non-zero.</p>
4056
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4057<h5>Example:</h5>
4058<pre>
4059 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
4060 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
4061 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
4062 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]4063 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]4064 &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]4065</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4066
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]4067</div>
4068
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4069<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4070<h4>
4071 <a name="i_and">'<tt>and</tt>' Instruction</a>
4072</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4073
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4074<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4075
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4076<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4077<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4078 &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]4079</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4080
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4081<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4082<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
4083 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4084
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4085<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4086<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4087 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4088 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4089
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4090<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4091<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4092
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4093<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4094 <tbody>
4095 <tr>
4096 <td>In0</td>
4097 <td>In1</td>
4098 <td>Out</td>
4099 </tr>
4100 <tr>
4101 <td>0</td>
4102 <td>0</td>
4103 <td>0</td>
4104 </tr>
4105 <tr>
4106 <td>0</td>
4107 <td>1</td>
4108 <td>0</td>
4109 </tr>
4110 <tr>
4111 <td>1</td>
4112 <td>0</td>
4113 <td>0</td>
4114 </tr>
4115 <tr>
4116 <td>1</td>
4117 <td>1</td>
4118 <td>1</td>
4119 </tr>
4120 </tbody>
4121</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4122
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4123<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4124<pre>
4125 &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]4126 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
4127 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4128</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4129</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4130<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4131<h4>
4132 <a name="i_or">'<tt>or</tt>' Instruction</a>
4133</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4134
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4135<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4136
4137<h5>Syntax:</h5>
4138<pre>
4139 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4140</pre>
4141
4142<h5>Overview:</h5>
4143<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4144 two operands.</p>
4145
4146<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4147<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4148 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4149 values. Both arguments must have identical types.</p>
4150
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4151<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4152<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4153
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4154<table border="1" cellspacing="0" cellpadding="4">
4155 <tbody>
4156 <tr>
4157 <td>In0</td>
4158 <td>In1</td>
4159 <td>Out</td>
4160 </tr>
4161 <tr>
4162 <td>0</td>
4163 <td>0</td>
4164 <td>0</td>
4165 </tr>
4166 <tr>
4167 <td>0</td>
4168 <td>1</td>
4169 <td>1</td>
4170 </tr>
4171 <tr>
4172 <td>1</td>
4173 <td>0</td>
4174 <td>1</td>
4175 </tr>
4176 <tr>
4177 <td>1</td>
4178 <td>1</td>
4179 <td>1</td>
4180 </tr>
4181 </tbody>
4182</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4183
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4184<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4185<pre>
4186 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4187 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4188 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4189</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4190
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4191</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4192
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4193<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4194<h4>
4195 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4196</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4197
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4198<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4199
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4200<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4201<pre>
4202 &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]4203</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4204
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4205<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4206<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4207 its two operands. The <tt>xor</tt> is used to implement the "one's
4208 complement" operation, which is the "~" operator in C.</p>
4209
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4210<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4211<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4212 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4213 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4214
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4215<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4216<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4217
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4218<table border="1" cellspacing="0" cellpadding="4">
4219 <tbody>
4220 <tr>
4221 <td>In0</td>
4222 <td>In1</td>
4223 <td>Out</td>
4224 </tr>
4225 <tr>
4226 <td>0</td>
4227 <td>0</td>
4228 <td>0</td>
4229 </tr>
4230 <tr>
4231 <td>0</td>
4232 <td>1</td>
4233 <td>1</td>
4234 </tr>
4235 <tr>
4236 <td>1</td>
4237 <td>0</td>
4238 <td>1</td>
4239 </tr>
4240 <tr>
4241 <td>1</td>
4242 <td>1</td>
4243 <td>0</td>
4244 </tr>
4245 </tbody>
4246</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4247
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4248<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4249<pre>
4250 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4251 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4252 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4253 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4254</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4255
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4256</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4257
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4258</div>
4259
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4260<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4261<h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4262 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4263</h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4264
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4265<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4266
4267<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4268 target-independent manner. These instructions cover the element-access and
4269 vector-specific operations needed to process vectors effectively. While LLVM
4270 does directly support these vector operations, many sophisticated algorithms
4271 will want to use target-specific intrinsics to take full advantage of a
4272 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4273
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4274<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4275<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4276 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4277</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4278
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4279<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4280
4281<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4282<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4283 &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]4284</pre>
4285
4286<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4287<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4288 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4289
4290
4291<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4292<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4293 of <a href="#t_vector">vector</a> type. The second operand is an index
4294 indicating the position from which to extract the element. The index may be
4295 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4296
4297<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4298<p>The result is a scalar of the same type as the element type of
4299 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4300 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4301 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4302
4303<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4304<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4305 &lt;result&gt; = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4306</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4307
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4308</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4309
4310<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4311<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4312 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4313</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4314
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4315<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4316
4317<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4318<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]4319 &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]4320</pre>
4321
4322<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4323<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4324 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4325
4326<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4327<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4328 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4329 whose type must equal the element type of the first operand. The third
4330 operand is an index indicating the position at which to insert the value.
4331 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4332
4333<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4334<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4335 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4336 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4337 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4338
4339<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4340<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4341 &lt;result&gt; = 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]4342</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4343
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4344</div>
4345
4346<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4347<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4348 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4349</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4350
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4351<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4352
4353<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4354<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4355 &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]4356</pre>
4357
4358<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4359<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4360 from two input vectors, returning a vector with the same element type as the
4361 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4362
4363<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4364<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4365 with types that match each other. The third argument is a shuffle mask whose
4366 element type is always 'i32'. The result of the instruction is a vector
4367 whose length is the same as the shuffle mask and whose element type is the
4368 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4369
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4370<p>The shuffle mask operand is required to be a constant vector with either
4371 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4372
4373<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4374<p>The elements of the two input vectors are numbered from left to right across
4375 both of the vectors. The shuffle mask operand specifies, for each element of
4376 the result vector, which element of the two input vectors the result element
4377 gets. The element selector may be undef (meaning "don't care") and the
4378 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4379
4380<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4381<pre>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4382 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4383 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4384 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4385 &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.
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4386 &lt;result&gt; = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4387 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4388 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4389 &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]4390</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4391
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4392</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]4393
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4394</div>
4395
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4396<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4397<h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4398 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4399</h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4400
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4401<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4402
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4403<p>LLVM supports several instructions for working with
4404 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4405
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4406<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4407<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4408 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4409</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4410
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4411<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4412
4413<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4414<pre>
4415 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4416</pre>
4417
4418<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4419<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4420 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4421
4422<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4423<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4424 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4425 <a href="#t_array">array</a> type. The operands are constant indices to
4426 specify which value to extract in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4427 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel7cf63ac2010-12-05 20:54:38 +0000[diff] [blame]4428 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4429 <ul>
4430 <li>Since the value being indexed is not a pointer, the first index is
4431 omitted and assumed to be zero.</li>
4432 <li>At least one index must be specified.</li>
4433 <li>Not only struct indices but also array indices must be in
4434 bounds.</li>
4435 </ul>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4436
4437<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4438<p>The result is the value at the position in the aggregate specified by the
4439 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4440
4441<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4442<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4443 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4444</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4445
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4446</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4447
4448<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4449<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4450 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4451</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4452
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4453<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4454
4455<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4456<pre>
Bill Wendlingf6a91cf2011-07-26 20:42:28 +0000[diff] [blame]4457 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt;{, &lt;idx&gt;}* <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4458</pre>
4459
4460<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4461<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4462 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4463
4464<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4465<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4466 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4467 <a href="#t_array">array</a> type. The second operand is a first-class
4468 value to insert. The following operands are constant indices indicating
4469 the position at which to insert the value in a similar manner as indices in a
Frits van Bommel7cf63ac2010-12-05 20:54:38 +0000[diff] [blame]4470 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4471 value to insert must have the same type as the value identified by the
4472 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4473
4474<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4475<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4476 that of <tt>val</tt> except that the value at the position specified by the
4477 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4478
4479<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4480<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4481 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4482 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4483 %agg3 = insertvalue {i32, {float}} %agg1, float %val, 1, 0 <i>; yields {i32 1, float %val}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4484</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4485
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4486</div>
4487
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4488</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4489
4490<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4491<h3>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4492 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4493</h3>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4494
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4495<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4496
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4497<p>A key design point of an SSA-based representation is how it represents
4498 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]4499 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4500 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4501
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4502<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4503<h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4504 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4505</h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4506
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4507<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4508
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4509<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4510<pre>
Dan Gohman2140a742010-05-28 01:14:11 +0000[diff] [blame]4511 &lt;result&gt; = alloca &lt;type&gt;[, &lt;ty&gt; &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4512</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4513
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4514<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4515<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4516 currently executing function, to be automatically released when this function
4517 returns to its caller. The object is always allocated in the generic address
4518 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4519
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4520<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4521<p>The '<tt>alloca</tt>' instruction
4522 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4523 runtime stack, returning a pointer of the appropriate type to the program.
4524 If "NumElements" is specified, it is the number of elements allocated,
4525 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4526 specified, the value result of the allocation is guaranteed to be aligned to
4527 at least that boundary. If not specified, or if zero, the target can choose
4528 to align the allocation on any convenient boundary compatible with the
4529 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4530
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4531<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4532
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4533<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]4534<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4535 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4536 memory is automatically released when the function returns. The
4537 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4538 variables that must have an address available. When the function returns
4539 (either with the <tt><a href="#i_ret">ret</a></tt>
4540 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4541 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4542
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4543<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4544<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]4545 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4546 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4547 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4548 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4549</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4550
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4551</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4552
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4553<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4554<h4>
4555 <a name="i_load">'<tt>load</tt>' Instruction</a>
4556</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4557
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4558<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4559
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4560<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4561<pre>
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4562 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4563 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4564 !&lt;index&gt; = !{ i32 1 }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4565</pre>
4566
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4567<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4568<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4569
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4570<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4571<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4572 from which to load. The pointer must point to
4573 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4574 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4575 number or order of execution of this <tt>load</tt> with other <a
4576 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4577
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4578<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4579 operation (that is, the alignment of the memory address). A value of 0 or an
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4580 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4581 alignment for the target. It is the responsibility of the code emitter to
4582 ensure that the alignment information is correct. Overestimating the
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4583 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4584 produce less efficient code. An alignment of 1 is always safe.</p>
4585
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4586<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4587 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4588 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4589 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4590 and code generator that this load is not expected to be reused in the cache.
4591 The code generator may select special instructions to save cache bandwidth,
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4592 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4593
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4594<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4595<p>The location of memory pointed to is loaded. If the value being loaded is of
4596 scalar type then the number of bytes read does not exceed the minimum number
4597 of bytes needed to hold all bits of the type. For example, loading an
4598 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4599 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4600 is undefined if the value was not originally written using a store of the
4601 same type.</p>
4602
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4603<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4604<pre>
4605 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4606 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4607 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4608</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4609
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4610</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4611
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4612<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4613<h4>
4614 <a name="i_store">'<tt>store</tt>' Instruction</a>
4615</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4616
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4617<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4618
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4619<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4620<pre>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4621 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
4622 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4623</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4624
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4625<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4626<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4627
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4628<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4629<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4630 and an address at which to store it. The type of the
4631 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4632 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4633 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4634 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4635 order of execution of this <tt>store</tt> with other <a
4636 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4637
4638<p>The optional constant "align" argument specifies the alignment of the
4639 operation (that is, the alignment of the memory address). A value of 0 or an
4640 omitted "align" argument means that the operation has the preferential
4641 alignment for the target. It is the responsibility of the code emitter to
4642 ensure that the alignment information is correct. Overestimating the
4643 alignment results in an undefined behavior. Underestimating the alignment may
4644 produce less efficient code. An alignment of 1 is always safe.</p>
4645
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4646<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4647 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4648 value 1. The existence of the !nontemporal metatadata on the
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4649 instruction tells the optimizer and code generator that this load is
4650 not expected to be reused in the cache. The code generator may
4651 select special instructions to save cache bandwidth, such as the
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4652 MOVNT instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4653
4654
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4655<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4656<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4657 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4658 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4659 does not exceed the minimum number of bytes needed to hold all bits of the
4660 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4661 writing a value of a type like <tt>i20</tt> with a size that is not an
4662 integral number of bytes, it is unspecified what happens to the extra bits
4663 that do not belong to the type, but they will typically be overwritten.</p>
4664
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4665<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4666<pre>
4667 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4668 store i32 3, i32* %ptr <i>; yields {void}</i>
4669 %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]4670</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4671
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4672</div>
4673
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4674<!-- _______________________________________________________________________ -->
Eli Friedmanfee02c62011-07-25 23:16:38 +0000[diff] [blame]4675<div class="doc_subsubsection"> <a name="i_fence">'<tt>fence</tt>'
4676Instruction</a> </div>
4677
4678<div class="doc_text">
4679
4680<h5>Syntax:</h5>
4681<pre>
4682 fence [singlethread] &lt;ordering&gt; <i>; yields {void}</i>
4683</pre>
4684
4685<h5>Overview:</h5>
4686<p>The '<tt>fence</tt>' instruction is used to introduce happens-before edges
4687between operations.</p>
4688
4689<h5>Arguments:</h5> <p>'<code>fence</code>' instructions take an <a
4690href="#ordering">ordering</a> argument which defines what
4691<i>synchronizes-with</i> edges they add. They can only be given
4692<code>acquire</code>, <code>release</code>, <code>acq_rel</code>, and
4693<code>seq_cst</code> orderings.</p>
4694
4695<h5>Semantics:</h5>
4696<p>A fence <var>A</var> which has (at least) <code>release</code> ordering
4697semantics <i>synchronizes with</i> a fence <var>B</var> with (at least)
4698<code>acquire</code> ordering semantics if and only if there exist atomic
4699operations <var>X</var> and <var>Y</var>, both operating on some atomic object
4700<var>M</var>, such that <var>A</var> is sequenced before <var>X</var>,
4701<var>X</var> modifies <var>M</var> (either directly or through some side effect
4702of a sequence headed by <var>X</var>), <var>Y</var> is sequenced before
4703<var>B</var>, and <var>Y</var> observes <var>M</var>. This provides a
4704<i>happens-before</i> dependency between <var>A</var> and <var>B</var>. Rather
4705than an explicit <code>fence</code>, one (but not both) of the atomic operations
4706<var>X</var> or <var>Y</var> might provide a <code>release</code> or
4707<code>acquire</code> (resp.) ordering constraint and still
4708<i>synchronize-with</i> the explicit <code>fence</code> and establish the
4709<i>happens-before</i> edge.</p>
4710
4711<p>A <code>fence</code> which has <code>seq_cst</code> ordering, in addition to
4712having both <code>acquire</code> and <code>release</code> semantics specified
4713above, participates in the global program order of other <code>seq_cst</code>
4714operations and/or fences.</p>
4715
4716<p>The optional "<a href="#singlethread"><code>singlethread</code></a>" argument
4717specifies that the fence only synchronizes with other fences in the same
4718thread. (This is useful for interacting with signal handlers.)</p>
4719
4720<p>FIXME: This instruction is a work in progress; until it is finished, use
4721 llvm.memory.barrier.
4722
4723<h5>Example:</h5>
4724<pre>
4725 fence acquire <i>; yields {void}</i>
4726 fence singlethread seq_cst <i>; yields {void}</i>
4727</pre>
4728
4729</div>
4730
4731<!-- _______________________________________________________________________ -->
Eli Friedmanc9a551e2011-07-28 21:48:00 +0000[diff] [blame]4732<div class="doc_subsubsection"> <a name="i_cmpxchg">'<tt>cmpxchg</tt>'
4733Instruction</a> </div>
4734
4735<div class="doc_text">
4736
4737<h5>Syntax:</h5>
4738<pre>
4739 [volatile] cmpxchg &lt;ty&gt;* &lt;pointer&gt;, &lt;ty&gt; &lt;cmp&gt;, &lt;ty&gt; &lt;new&gt; [singlethread] &lt;ordering&gt; <i>; yields {ty}</i>
4740</pre>
4741
4742<h5>Overview:</h5>
4743<p>The '<tt>cmpxchg</tt>' instruction is used to atomically modify memory.
4744It loads a value in memory and compares it to a given value. If they are
4745equal, it stores a new value into the memory.</p>
4746
4747<h5>Arguments:</h5>
4748<p>There are three arguments to the '<code>cmpxchg</code>' instruction: an
4749address to operate on, a value to compare to the value currently be at that
4750address, and a new value to place at that address if the compared values are
4751equal. The type of '<var>&lt;cmp&gt;</var>' must be an integer type whose
4752bit width is a power of two greater than or equal to eight and less than
4753or equal to a target-specific size limit. '<var>&lt;cmp&gt;</var>' and
4754'<var>&lt;new&gt;</var>' must have the same type, and the type of
4755'<var>&lt;pointer&gt;</var>' must be a pointer to that type. If the
4756<code>cmpxchg</code> is marked as <code>volatile</code>, then the
4757optimizer is not allowed to modify the number or order of execution
4758of this <code>cmpxchg</code> with other <a href="#volatile">volatile
4759operations</a>.</p>
4760
4761<!-- FIXME: Extend allowed types. -->
4762
4763<p>The <a href="#ordering"><var>ordering</var></a> argument specifies how this
4764<code>cmpxchg</code> synchronizes with other atomic operations.</p>
4765
4766<p>The optional "<code>singlethread</code>" argument declares that the
4767<code>cmpxchg</code> is only atomic with respect to code (usually signal
4768handlers) running in the same thread as the <code>cmpxchg</code>. Otherwise the
4769cmpxchg is atomic with respect to all other code in the system.</p>
4770
4771<p>The pointer passed into cmpxchg must have alignment greater than or equal to
4772the size in memory of the operand.
4773
4774<h5>Semantics:</h5>
4775<p>The contents of memory at the location specified by the
4776'<tt>&lt;pointer&gt;</tt>' operand is read and compared to
4777'<tt>&lt;cmp&gt;</tt>'; if the read value is the equal,
4778'<tt>&lt;new&gt;</tt>' is written. The original value at the location
4779is returned.
4780
4781<p>A successful <code>cmpxchg</code> is a read-modify-write instruction for the
4782purpose of identifying <a href="#release_sequence">release sequences</a>. A
4783failed <code>cmpxchg</code> is equivalent to an atomic load with an ordering
4784parameter determined by dropping any <code>release</code> part of the
4785<code>cmpxchg</code>'s ordering.</p>
4786
4787<!--
4788FIXME: Is compare_exchange_weak() necessary? (Consider after we've done
4789optimization work on ARM.)
4790
4791FIXME: Is a weaker ordering constraint on failure helpful in practice?
4792-->
4793
4794<h5>Example:</h5>
4795<pre>
4796entry:
4797 %orig = atomic <a href="#i_load">load</a> i32* %ptr unordered <i>; yields {i32}</i>
4798 <a href="#i_br">br</a> label %loop
4799
4800loop:
4801 %cmp = <a href="#i_phi">phi</a> i32 [ %orig, %entry ], [%old, %loop]
4802 %squared = <a href="#i_mul">mul</a> i32 %cmp, %cmp
4803 %old = cmpxchg i32* %ptr, i32 %cmp, i32 %squared <i>; yields {i32}</i>
4804 %success = <a href="#i_icmp">icmp</a> eq i32 %cmp, %old
4805 <a href="#i_br">br</a> i1 %success, label %done, label %loop
4806
4807done:
4808 ...
4809</pre>
4810
4811</div>
4812
4813<!-- _______________________________________________________________________ -->
4814<div class="doc_subsubsection"> <a name="i_atomicrmw">'<tt>atomicrmw</tt>'
4815Instruction</a> </div>
4816
4817<div class="doc_text">
4818
4819<h5>Syntax:</h5>
4820<pre>
4821 [volatile] atomicrmw &lt;operation&gt; &lt;ty&gt;* &lt;pointer&gt;, &lt;ty&gt; &lt;value&gt; [singlethread] &lt;ordering&gt; <i>; yields {ty}</i>
4822</pre>
4823
4824<h5>Overview:</h5>
4825<p>The '<tt>atomicrmw</tt>' instruction is used to atomically modify memory.</p>
4826
4827<h5>Arguments:</h5>
4828<p>There are three arguments to the '<code>atomicrmw</code>' instruction: an
4829operation to apply, an address whose value to modify, an argument to the
4830operation. The operation must be one of the following keywords:</p>
4831<ul>
4832 <li>xchg</li>
4833 <li>add</li>
4834 <li>sub</li>
4835 <li>and</li>
4836 <li>nand</li>
4837 <li>or</li>
4838 <li>xor</li>
4839 <li>max</li>
4840 <li>min</li>
4841 <li>umax</li>
4842 <li>umin</li>
4843</ul>
4844
4845<p>The type of '<var>&lt;value&gt;</var>' must be an integer type whose
4846bit width is a power of two greater than or equal to eight and less than
4847or equal to a target-specific size limit. The type of the
4848'<code>&lt;pointer&gt;</code>' operand must be a pointer to that type.
4849If the <code>atomicrmw</code> is marked as <code>volatile</code>, then the
4850optimizer is not allowed to modify the number or order of execution of this
4851<code>atomicrmw</code> with other <a href="#volatile">volatile
4852 operations</a>.</p>
4853
4854<!-- FIXME: Extend allowed types. -->
4855
4856<h5>Semantics:</h5>
4857<p>The contents of memory at the location specified by the
4858'<tt>&lt;pointer&gt;</tt>' operand are atomically read, modified, and written
4859back. The original value at the location is returned. The modification is
4860specified by the <var>operation</var> argument:</p>
4861
4862<ul>
4863 <li>xchg: <code>*ptr = val</code></li>
4864 <li>add: <code>*ptr = *ptr + val</code></li>
4865 <li>sub: <code>*ptr = *ptr - val</code></li>
4866 <li>and: <code>*ptr = *ptr &amp; val</code></li>
4867 <li>nand: <code>*ptr = ~(*ptr &amp; val)</code></li>
4868 <li>or: <code>*ptr = *ptr | val</code></li>
4869 <li>xor: <code>*ptr = *ptr ^ val</code></li>
4870 <li>max: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using a signed comparison)</li>
4871 <li>min: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using a signed comparison)</li>
4872 <li>umax: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4873 <li>umin: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4874</ul>
4875
4876<h5>Example:</h5>
4877<pre>
4878 %old = atomicrmw add i32* %ptr, i32 1 acquire <i>; yields {i32}</i>
4879</pre>
4880
4881</div>
4882
4883<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4884<h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4885 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4886</h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4887
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4888<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4889
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4890<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4891<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4892 &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]4893 &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]4894</pre>
4895
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4896<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4897<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4898 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4899 It performs address calculation only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4900
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4901<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4902<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4903 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4904 elements of the aggregate object are indexed. The interpretation of each
4905 index is dependent on the type being indexed into. The first index always
4906 indexes the pointer value given as the first argument, the second index
4907 indexes a value of the type pointed to (not necessarily the value directly
4908 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4909 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4910 vectors, and structs. Note that subsequent types being indexed into
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4911 can never be pointers, since that would require loading the pointer before
4912 continuing calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4913
4914<p>The type of each index argument depends on the type it is indexing into.
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4915 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4916 integer <b>constants</b> are allowed. When indexing into an array, pointer
4917 or vector, integers of any width are allowed, and they are not required to be
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4918 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4919
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4920<p>For example, let's consider a C code fragment and how it gets compiled to
4921 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4922
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4923<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4924struct RT {
4925 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4926 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4927 char C;
4928};
4929struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4930 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4931 double Y;
4932 struct RT Z;
4933};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4934
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4935int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4936 return &amp;s[1].Z.B[5][13];
4937}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4938</pre>
4939
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4940<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4941
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4942<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4943%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4944%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4945
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4946define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4947entry:
4948 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4949 ret i32* %reg
4950}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4951</pre>
4952
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4953<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4954<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]4955 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4956 }</tt>' type, a structure. The second index indexes into the third element
4957 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4958 i8 }</tt>' type, another structure. The third index indexes into the second
4959 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4960 array. The two dimensions of the array are subscripted into, yielding an
4961 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4962 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4963
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4964<p>Note that it is perfectly legal to index partially through a structure,
4965 returning a pointer to an inner element. Because of this, the LLVM code for
4966 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4967
4968<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4969 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4970 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4971 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4972 %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]4973 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4974 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4975 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4976 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4977</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4978
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4979<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]4980 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4981 base pointer is not an <i>in bounds</i> address of an allocated object,
4982 or if any of the addresses that would be formed by successive addition of
4983 the offsets implied by the indices to the base address with infinitely
4984 precise arithmetic are not an <i>in bounds</i> address of that allocated
4985 object. The <i>in bounds</i> addresses for an allocated object are all
4986 the addresses that point into the object, plus the address one byte past
4987 the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4988
4989<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4990 the base address with silently-wrapping two's complement arithmetic, and
4991 the result value of the <tt>getelementptr</tt> may be outside the object
4992 pointed to by the base pointer. The result value may not necessarily be
4993 used to access memory though, even if it happens to point into allocated
4994 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4995 section for more information.</p>
4996
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4997<p>The getelementptr instruction is often confusing. For some more insight into
4998 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4999
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]5000<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5001<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5002 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]5003 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
5004 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5005 %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]5006 <i>; yields i8*:eptr</i>
5007 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]5008 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]5009 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5010</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5011
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]5012</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]5013
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5014</div>
5015
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5016<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5017<h3>
5018 <a name="convertops">Conversion Operations</a>
5019</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5020
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5021<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5022
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5023<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5024 which all take a single operand and a type. They perform various bit
5025 conversions on the operand.</p>
5026
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5027<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5028<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5029 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5030</h4>
5031
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5032<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5033
5034<h5>Syntax:</h5>
5035<pre>
5036 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5037</pre>
5038
5039<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5040<p>The '<tt>trunc</tt>' instruction truncates its operand to the
5041 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5042
5043<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5044<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
5045 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5046 of the same number of integers.
5047 The bit size of the <tt>value</tt> must be larger than
5048 the bit size of the destination type, <tt>ty2</tt>.
5049 Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5050
5051<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5052<p>The '<tt>trunc</tt>' instruction truncates the high order bits
5053 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
5054 source size must be larger than the destination size, <tt>trunc</tt> cannot
5055 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5056
5057<h5>Example:</h5>
5058<pre>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5059 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
5060 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
5061 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
5062 %W = trunc &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i8&gt; <i>; yields &lt;i8 8, i8 7&gt;</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5063</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5064
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5065</div>
5066
5067<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5068<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5069 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5070</h4>
5071
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5072<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5073
5074<h5>Syntax:</h5>
5075<pre>
5076 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5077</pre>
5078
5079<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5080<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5081 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5082
5083
5084<h5>Arguments:</h5>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]5085<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
5086 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5087 of the same number of integers.
5088 The bit size of the <tt>value</tt> must be smaller than
5089 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5090 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5091
5092<h5>Semantics:</h5>
5093<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]5094 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5095
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]5096<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]5097
5098<h5>Example:</h5>
5099<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5100 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5101 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]5102 %Z = zext &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i32&gt; <i>; yields &lt;i32 8, i32 7&gt;</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5103</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5104
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5105</div>
5106
5107<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5108<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5109 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5110</h4>
5111
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5112<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5113
5114<h5>Syntax:</h5>
5115<pre>
5116 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5117</pre>
5118
5119<h5>Overview:</h5>
5120<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
5121
5122<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5123<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
5124 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5125 of the same number of integers.
5126 The bit size of the <tt>value</tt> must be smaller than
5127 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5128 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5129
5130<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5131<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
5132 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
5133 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5134
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5135<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]5136
5137<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5138<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5139 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5140 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]5141 %Z = sext &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i32&gt; <i>; yields &lt;i32 8, i32 7&gt;</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5142</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5143
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5144</div>
5145
5146<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5147<h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5148 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5149</h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5150
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5151<div>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5152
5153<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5154<pre>
5155 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5156</pre>
5157
5158<h5>Overview:</h5>
5159<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5160 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5161
5162<h5>Arguments:</h5>
5163<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5164 point</a> value to cast and a <a href="#t_floating">floating point</a> type
5165 to cast it to. The size of <tt>value</tt> must be larger than the size of
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5166 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5167 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5168
5169<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5170<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5171 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5172 <a href="#t_floating">floating point</a> type. If the value cannot fit
5173 within the destination type, <tt>ty2</tt>, then the results are
5174 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5175
5176<h5>Example:</h5>
5177<pre>
5178 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
5179 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
5180</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5181
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]5182</div>
5183
5184<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5185<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5186 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5187</h4>
5188
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5189<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5190
5191<h5>Syntax:</h5>
5192<pre>
5193 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5194</pre>
5195
5196<h5>Overview:</h5>
5197<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]5198 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5199
5200<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5201<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5202 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
5203 a <a href="#t_floating">floating point</a> type to cast it to. The source
5204 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5205
5206<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5207<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5208 <a href="#t_floating">floating point</a> type to a larger
5209 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
5210 used to make a <i>no-op cast</i> because it always changes bits. Use
5211 <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]5212
5213<h5>Example:</h5>
5214<pre>
Nick Lewycky9feca672011-03-31 18:20:19 +0000[diff] [blame]5215 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
5216 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5217</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5218
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5219</div>
5220
5221<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5222<h4>
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]5223 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5224</h4>
5225
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5226<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5227
5228<h5>Syntax:</h5>
5229<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5230 &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]5231</pre>
5232
5233<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5234<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5235 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5236
5237<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5238<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
5239 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5240 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5241 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5242 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5243
5244<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5245<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5246 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5247 towards zero) unsigned integer value. If the value cannot fit
5248 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5249
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5250<h5>Example:</h5>
5251<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]5252 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]5253 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]5254 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5255</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5256
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5257</div>
5258
5259<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5260<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5261 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5262</h4>
5263
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5264<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5265
5266<h5>Syntax:</h5>
5267<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5268 &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]5269</pre>
5270
5271<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5272<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5273 <a href="#t_floating">floating point</a> <tt>value</tt> to
5274 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5275
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5276<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5277<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
5278 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5279 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5280 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5281 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5282
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5283<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5284<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5285 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5286 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
5287 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5288
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]5289<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5290<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5291 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]5292 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]5293 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5294</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5295
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5296</div>
5297
5298<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5299<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5300 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5301</h4>
5302
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5303<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5304
5305<h5>Syntax:</h5>
5306<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5307 &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]5308</pre>
5309
5310<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5311<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5312 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5313
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5314<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]5315<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]5316 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5317 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5318 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5319 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5320
5321<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5322<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5323 integer quantity and converts it to the corresponding floating point
5324 value. If the value cannot fit in the floating point value, the results are
5325 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5326
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5327<h5>Example:</h5>
5328<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5329 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5330 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5331</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5332
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5333</div>
5334
5335<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5336<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5337 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5338</h4>
5339
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5340<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5341
5342<h5>Syntax:</h5>
5343<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]5344 &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]5345</pre>
5346
5347<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5348<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5349 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5350
5351<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]5352<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]5353 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5354 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5355 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5356 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5357
5358<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5359<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5360 quantity and converts it to the corresponding floating point value. If the
5361 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5362
5363<h5>Example:</h5>
5364<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5365 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5366 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5367</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5368
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5369</div>
5370
5371<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5372<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5373 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5374</h4>
5375
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5376<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5377
5378<h5>Syntax:</h5>
5379<pre>
5380 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5381</pre>
5382
5383<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5384<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5385 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5386
5387<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5388<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5389 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5390 <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]5391
5392<h5>Semantics:</h5>
5393<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5394 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5395 truncating or zero extending that value to the size of the integer type. If
5396 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5397 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5398 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5399 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5400
5401<h5>Example:</h5>
5402<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5403 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5404 %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]5405</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5406
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5407</div>
5408
5409<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5410<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5411 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5412</h4>
5413
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5414<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5415
5416<h5>Syntax:</h5>
5417<pre>
5418 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5419</pre>
5420
5421<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5422<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5423 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5424
5425<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]5426<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5427 value to cast, and a type to cast it to, which must be a
5428 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5429
5430<h5>Semantics:</h5>
5431<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5432 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5433 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5434 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5435 than the size of a pointer then a zero extension is done. If they are the
5436 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5437
5438<h5>Example:</h5>
5439<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5440 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]5441 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5442 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5443</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5444
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5445</div>
5446
5447<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5448<h4>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5449 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5450</h4>
5451
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5452<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5453
5454<h5>Syntax:</h5>
5455<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5456 &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]5457</pre>
5458
5459<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5460<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5461 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5462
5463<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5464<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5465 non-aggregate first class value, and a type to cast it to, which must also be
5466 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5467 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5468 identical. If the source type is a pointer, the destination type must also be
5469 a pointer. This instruction supports bitwise conversion of vectors to
5470 integers and to vectors of other types (as long as they have the same
5471 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5472
5473<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5474<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5475 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5476 this conversion. The conversion is done as if the <tt>value</tt> had been
5477 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5478 be converted to other pointer types with this instruction. To convert
5479 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5480 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5481
5482<h5>Example:</h5>
5483<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5484 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5485 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5486 %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]5487</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5488
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5489</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5490
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5491</div>
5492
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5493<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5494<h3>
5495 <a name="otherops">Other Operations</a>
5496</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5497
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5498<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5499
5500<p>The instructions in this category are the "miscellaneous" instructions, which
5501 defy better classification.</p>
5502
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5503<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5504<h4>
5505 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5506</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5507
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5508<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5509
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5510<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5511<pre>
5512 &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]5513</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5514
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5515<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5516<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5517 boolean values based on comparison of its two integer, integer vector, or
5518 pointer operands.</p>
5519
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5520<h5>Arguments:</h5>
5521<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5522 the condition code indicating the kind of comparison to perform. It is not a
5523 value, just a keyword. The possible condition code are:</p>
5524
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5525<ol>
5526 <li><tt>eq</tt>: equal</li>
5527 <li><tt>ne</tt>: not equal </li>
5528 <li><tt>ugt</tt>: unsigned greater than</li>
5529 <li><tt>uge</tt>: unsigned greater or equal</li>
5530 <li><tt>ult</tt>: unsigned less than</li>
5531 <li><tt>ule</tt>: unsigned less or equal</li>
5532 <li><tt>sgt</tt>: signed greater than</li>
5533 <li><tt>sge</tt>: signed greater or equal</li>
5534 <li><tt>slt</tt>: signed less than</li>
5535 <li><tt>sle</tt>: signed less or equal</li>
5536</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5537
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]5538<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5539 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5540 typed. They must also be identical types.</p>
5541
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5542<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5543<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5544 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5545 either an <a href="#t_integer"><tt>i1</tt></a> or vector of <tt>i1</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5546 result, as follows:</p>
5547
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5548<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5549 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5550 <tt>false</tt> otherwise. No sign interpretation is necessary or
5551 performed.</li>
5552
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5553 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5554 <tt>false</tt> otherwise. No sign interpretation is necessary or
5555 performed.</li>
5556
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5557 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5558 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5559
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5560 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5561 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5562 to <tt>op2</tt>.</li>
5563
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5564 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5565 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5566
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5567 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5568 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5569
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5570 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5571 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5572
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5573 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5574 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5575 to <tt>op2</tt>.</li>
5576
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5577 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5578 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5579
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5580 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5581 <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]5582</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5583
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5584<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5585 values are compared as if they were integers.</p>
5586
5587<p>If the operands are integer vectors, then they are compared element by
5588 element. The result is an <tt>i1</tt> vector with the same number of elements
5589 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5590
5591<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5592<pre>
5593 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5594 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5595 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5596 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5597 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5598 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5599</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5600
5601<p>Note that the code generator does not yet support vector types with
5602 the <tt>icmp</tt> instruction.</p>
5603
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5604</div>
5605
5606<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5607<h4>
5608 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5609</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5610
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5611<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5612
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5613<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5614<pre>
5615 &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]5616</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5617
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5618<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5619<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5620 values based on comparison of its operands.</p>
5621
5622<p>If the operands are floating point scalars, then the result type is a boolean
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5623(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5624
5625<p>If the operands are floating point vectors, then the result type is a vector
5626 of boolean with the same number of elements as the operands being
5627 compared.</p>
5628
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5629<h5>Arguments:</h5>
5630<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5631 the condition code indicating the kind of comparison to perform. It is not a
5632 value, just a keyword. The possible condition code are:</p>
5633
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5634<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5635 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5636 <li><tt>oeq</tt>: ordered and equal</li>
5637 <li><tt>ogt</tt>: ordered and greater than </li>
5638 <li><tt>oge</tt>: ordered and greater than or equal</li>
5639 <li><tt>olt</tt>: ordered and less than </li>
5640 <li><tt>ole</tt>: ordered and less than or equal</li>
5641 <li><tt>one</tt>: ordered and not equal</li>
5642 <li><tt>ord</tt>: ordered (no nans)</li>
5643 <li><tt>ueq</tt>: unordered or equal</li>
5644 <li><tt>ugt</tt>: unordered or greater than </li>
5645 <li><tt>uge</tt>: unordered or greater than or equal</li>
5646 <li><tt>ult</tt>: unordered or less than </li>
5647 <li><tt>ule</tt>: unordered or less than or equal</li>
5648 <li><tt>une</tt>: unordered or not equal</li>
5649 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5650 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5651</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5652
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5653<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5654 <i>unordered</i> means that either operand may be a QNAN.</p>
5655
5656<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5657 a <a href="#t_floating">floating point</a> type or
5658 a <a href="#t_vector">vector</a> of floating point type. They must have
5659 identical types.</p>
5660
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5661<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]5662<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5663 according to the condition code given as <tt>cond</tt>. If the operands are
5664 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5665 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5666 follows:</p>
5667
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5668<ol>
5669 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5670
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5671 <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]5672 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5673
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5674 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5675 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5676
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5677 <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]5678 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5679
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5680 <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]5681 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5682
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5683 <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]5684 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5685
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5686 <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]5687 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5688
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5689 <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]5690
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5691 <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]5692 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5693
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5694 <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]5695 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5696
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5697 <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]5698 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5699
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5700 <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]5701 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5702
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5703 <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]5704 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5705
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5706 <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]5707 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5708
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5709 <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]5710
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5711 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5712</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5713
5714<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5715<pre>
5716 &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]5717 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5718 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5719 &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]5720</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5721
5722<p>Note that the code generator does not yet support vector types with
5723 the <tt>fcmp</tt> instruction.</p>
5724
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5725</div>
5726
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5727<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5728<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5729 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5730</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5731
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5732<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5733
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5734<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5735<pre>
5736 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5737</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5738
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5739<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5740<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5741 SSA graph representing the function.</p>
5742
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5743<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5744<p>The type of the incoming values is specified with the first type field. After
5745 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5746 one pair for each predecessor basic block of the current block. Only values
5747 of <a href="#t_firstclass">first class</a> type may be used as the value
5748 arguments to the PHI node. Only labels may be used as the label
5749 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5750
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5751<p>There must be no non-phi instructions between the start of a basic block and
5752 the PHI instructions: i.e. PHI instructions must be first in a basic
5753 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5754
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5755<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5756 occur on the edge from the corresponding predecessor block to the current
5757 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5758 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]5759
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5760<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5761<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5762 specified by the pair corresponding to the predecessor basic block that
5763 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5764
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5765<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5766<pre>
5767Loop: ; Infinite loop that counts from 0 on up...
5768 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5769 %nextindvar = add i32 %indvar, 1
5770 br label %Loop
5771</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5772
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5773</div>
5774
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5775<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5776<h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5777 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5778</h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5779
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5780<div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5781
5782<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5783<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5784 &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>
5785
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5786 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5787</pre>
5788
5789<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5790<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5791 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5792
5793
5794<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5795<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5796 values indicating the condition, and two values of the
5797 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5798 vectors and the condition is a scalar, then entire vectors are selected, not
5799 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5800
5801<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5802<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5803 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5804
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5805<p>If the condition is a vector of i1, then the value arguments must be vectors
5806 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5807
5808<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5809<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5810 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5811</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5812
5813<p>Note that the code generator does not yet support conditions
5814 with vector type.</p>
5815
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5816</div>
5817
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]5818<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5819<h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5820 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5821</h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5822
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5823<div>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5824
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5825<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5826<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]5827 &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]5828</pre>
5829
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5830<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5831<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5832
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5833<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5834<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5835
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5836<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5837 <li>The optional "tail" marker indicates that the callee function does not
5838 access any allocas or varargs in the caller. Note that calls may be
5839 marked "tail" even if they do not occur before
5840 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5841 present, the function call is eligible for tail call optimization,
5842 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Cheng59676492010-03-08 21:05:02 +0000[diff] [blame]5843 optimized into a jump</a>. The code generator may optimize calls marked
5844 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5845 sibling call optimization</a> when the caller and callee have
5846 matching signatures, or 2) forced tail call optimization when the
5847 following extra requirements are met:
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5848 <ul>
5849 <li>Caller and callee both have the calling
5850 convention <tt>fastcc</tt>.</li>
5851 <li>The call is in tail position (ret immediately follows call and ret
5852 uses value of call or is void).</li>
5853 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohman6232f732010-03-02 01:08:11 +0000[diff] [blame]5854 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5855 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5856 constraints are met.</a></li>
5857 </ul>
5858 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5859
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5860 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5861 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5862 defaults to using C calling conventions. The calling convention of the
5863 call must match the calling convention of the target function, or else the
5864 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5865
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5866 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5867 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5868 '<tt>inreg</tt>' attributes are valid here.</li>
5869
5870 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5871 type of the return value. Functions that return no value are marked
5872 <tt><a href="#t_void">void</a></tt>.</li>
5873
5874 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5875 being invoked. The argument types must match the types implied by this
5876 signature. This type can be omitted if the function is not varargs and if
5877 the function type does not return a pointer to a function.</li>
5878
5879 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5880 be invoked. In most cases, this is a direct function invocation, but
5881 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5882 to function value.</li>
5883
5884 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]5885 signature argument types and parameter attributes. All arguments must be
5886 of <a href="#t_firstclass">first class</a> type. If the function
5887 signature indicates the function accepts a variable number of arguments,
5888 the extra arguments can be specified.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5889
5890 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5891 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5892 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5893</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5894
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5895<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5896<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5897 a specified function, with its incoming arguments bound to the specified
5898 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5899 function, control flow continues with the instruction after the function
5900 call, and the return value of the function is bound to the result
5901 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5902
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5903<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5904<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5905 %retval = call i32 @test(i32 %argc)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5906 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5907 %X = tail call i32 @foo() <i>; yields i32</i>
5908 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5909 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5910
5911 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5912 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5913 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5914 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5915 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5916 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5917</pre>
5918
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5919<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5920standard C99 library as being the C99 library functions, and may perform
5921optimizations or generate code for them under that assumption. This is
5922something we'd like to change in the future to provide better support for
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5923freestanding environments and non-C-based languages.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5924
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5925</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5926
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5927<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5928<h4>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5929 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5930</h4>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5931
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5932<div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5933
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5934<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5935<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5936 &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]5937</pre>
5938
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5939<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5940<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5941 the "variable argument" area of a function call. It is used to implement the
5942 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5943
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5944<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5945<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5946 argument. It returns a value of the specified argument type and increments
5947 the <tt>va_list</tt> to point to the next argument. The actual type
5948 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5949
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5950<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5951<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5952 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5953 to the next argument. For more information, see the variable argument
5954 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5955
5956<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]5957 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5958 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5959
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5960<p><tt>va_arg</tt> is an LLVM instruction instead of
5961 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5962 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5963
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5964<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5965<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5966
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5967<p>Note that the code generator does not yet fully support va_arg on many
5968 targets. Also, it does not currently support va_arg with aggregate types on
5969 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5970
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5971</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5972
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5973</div>
5974
5975</div>
5976
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5977<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5978<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5979<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5980
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5981<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5982
5983<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5984 well known names and semantics and are required to follow certain
5985 restrictions. Overall, these intrinsics represent an extension mechanism for
5986 the LLVM language that does not require changing all of the transformations
5987 in LLVM when adding to the language (or the bitcode reader/writer, the
5988 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5989
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5990<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5991 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5992 begin with this prefix. Intrinsic functions must always be external
5993 functions: you cannot define the body of intrinsic functions. Intrinsic
5994 functions may only be used in call or invoke instructions: it is illegal to
5995 take the address of an intrinsic function. Additionally, because intrinsic
5996 functions are part of the LLVM language, it is required if any are added that
5997 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5998
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5999<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
6000 family of functions that perform the same operation but on different data
6001 types. Because LLVM can represent over 8 million different integer types,
6002 overloading is used commonly to allow an intrinsic function to operate on any
6003 integer type. One or more of the argument types or the result type can be
6004 overloaded to accept any integer type. Argument types may also be defined as
6005 exactly matching a previous argument's type or the result type. This allows
6006 an intrinsic function which accepts multiple arguments, but needs all of them
6007 to be of the same type, to only be overloaded with respect to a single
6008 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6009
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6010<p>Overloaded intrinsics will have the names of its overloaded argument types
6011 encoded into its function name, each preceded by a period. Only those types
6012 which are overloaded result in a name suffix. Arguments whose type is matched
6013 against another type do not. For example, the <tt>llvm.ctpop</tt> function
6014 can take an integer of any width and returns an integer of exactly the same
6015 integer width. This leads to a family of functions such as
6016 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
6017 %val)</tt>. Only one type, the return type, is overloaded, and only one type
6018 suffix is required. Because the argument's type is matched against the return
6019 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6020
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6021<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6022 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6023
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6024<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6025<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6026 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6027</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6028
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6029<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6030
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6031<p>Variable argument support is defined in LLVM with
6032 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
6033 intrinsic functions. These functions are related to the similarly named
6034 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6035
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6036<p>All of these functions operate on arguments that use a target-specific value
6037 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
6038 not define what this type is, so all transformations should be prepared to
6039 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6040
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]6041<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]6042 instruction and the variable argument handling intrinsic functions are
6043 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6044
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]6045<pre class="doc_code">
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6046define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6047 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6048 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6049 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6050 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6051
6052 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6053 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6054
6055 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6056 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6057 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6058 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6059 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6060
6061 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6062 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]6063 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6064}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]6065
6066declare void @llvm.va_start(i8*)
6067declare void @llvm.va_copy(i8*, i8*)
6068declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6069</pre>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6070
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6071<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6072<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6073 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6074</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6075
6076
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6077<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6078
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6079<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6080<pre>
6081 declare void %llvm.va_start(i8* &lt;arglist&gt;)
6082</pre>
6083
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6084<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6085<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
6086 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]6087
6088<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6089<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]6090
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6091<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6092<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]6093 macro available in C. In a target-dependent way, it initializes
6094 the <tt>va_list</tt> element to which the argument points, so that the next
6095 call to <tt>va_arg</tt> will produce the first variable argument passed to
6096 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
6097 need to know the last argument of the function as the compiler can figure
6098 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]6099
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6100</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6101
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6102<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6103<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6104 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6105</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6106
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6107<div>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6108
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6109<h5>Syntax:</h5>
6110<pre>
6111 declare void @llvm.va_end(i8* &lt;arglist&gt;)
6112</pre>
6113
6114<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6115<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6116 which has been initialized previously
6117 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
6118 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6119
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6120<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6121<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]6122
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6123<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6124<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]6125 macro available in C. In a target-dependent way, it destroys
6126 the <tt>va_list</tt> element to which the argument points. Calls
6127 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
6128 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
6129 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]6130
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6131</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6132
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6133<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6134<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6135 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6136</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6137
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6138<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6139
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6140<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6141<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6142 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6143</pre>
6144
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6145<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6146<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6147 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6148
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6149<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]6150<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]6151 The second argument is a pointer to a <tt>va_list</tt> element to copy
6152 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6153
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]6154<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]6155<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]6156 macro available in C. In a target-dependent way, it copies the
6157 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
6158 element. This intrinsic is necessary because
6159 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
6160 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6161
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6162</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6163
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6164</div>
6165
Bill Wendling537603b2011-07-31 06:45:03 +0000[diff] [blame]6166</div>
6167
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6168<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6169<h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6170 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6171</h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6172
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6173<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6174
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6175<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]6176Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6177intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
6178roots on the stack</a>, as well as garbage collector implementations that
6179require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
6180barriers. Front-ends for type-safe garbage collected languages should generate
6181these intrinsics to make use of the LLVM garbage collectors. For more details,
6182see <a href="GarbageCollection.html">Accurate Garbage Collection with
6183LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]6184
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6185<p>The garbage collection intrinsics only operate on objects in the generic
6186 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]6187
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6188<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6189<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6190 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6191</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6192
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6193<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6194
6195<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6196<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6197 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6198</pre>
6199
6200<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]6201<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]6202 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6203
6204<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6205<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6206 root pointer. The second pointer (which must be either a constant or a
6207 global value address) contains the meta-data to be associated with the
6208 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6209
6210<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]6211<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]6212 location. At compile-time, the code generator generates information to allow
6213 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
6214 intrinsic may only be used in a function which <a href="#gc">specifies a GC
6215 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6216
6217</div>
6218
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6219<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6220<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6221 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6222</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6223
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6224<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6225
6226<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6227<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6228 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6229</pre>
6230
6231<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6232<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6233 locations, allowing garbage collector implementations that require read
6234 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6235
6236<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]6237<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]6238 allocated from the garbage collector. The first object is a pointer to the
6239 start of the referenced object, if needed by the language runtime (otherwise
6240 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6241
6242<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6243<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6244 instruction, but may be replaced with substantially more complex code by the
6245 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
6246 may only be used in a function which <a href="#gc">specifies a GC
6247 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6248
6249</div>
6250
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6251<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6252<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6253 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6254</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6255
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6256<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6257
6258<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6259<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6260 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6261</pre>
6262
6263<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6264<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6265 locations, allowing garbage collector implementations that require write
6266 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6267
6268<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]6269<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]6270 object to store it to, and the third is the address of the field of Obj to
6271 store to. If the runtime does not require a pointer to the object, Obj may
6272 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6273
6274<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6275<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6276 instruction, but may be replaced with substantially more complex code by the
6277 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
6278 may only be used in a function which <a href="#gc">specifies a GC
6279 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6280
6281</div>
6282
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6283</div>
6284
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]6285<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6286<h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6287 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6288</h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6289
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6290<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6291
6292<p>These intrinsics are provided by LLVM to expose special features that may
6293 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6294
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6295<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6296<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6297 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6298</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6299
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6300<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6301
6302<h5>Syntax:</h5>
6303<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6304 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6305</pre>
6306
6307<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6308<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
6309 target-specific value indicating the return address of the current function
6310 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6311
6312<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6313<p>The argument to this intrinsic indicates which function to return the address
6314 for. Zero indicates the calling function, one indicates its caller, etc.
6315 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6316
6317<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6318<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
6319 indicating the return address of the specified call frame, or zero if it
6320 cannot be identified. The value returned by this intrinsic is likely to be
6321 incorrect or 0 for arguments other than zero, so it should only be used for
6322 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6323
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6324<p>Note that calling this intrinsic does not prevent function inlining or other
6325 aggressive transformations, so the value returned may not be that of the
6326 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6327
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6328</div>
6329
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6330<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6331<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6332 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6333</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6334
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6335<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6336
6337<h5>Syntax:</h5>
6338<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6339 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6340</pre>
6341
6342<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6343<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6344 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6345
6346<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6347<p>The argument to this intrinsic indicates which function to return the frame
6348 pointer for. Zero indicates the calling function, one indicates its caller,
6349 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6350
6351<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6352<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6353 indicating the frame address of the specified call frame, or zero if it
6354 cannot be identified. The value returned by this intrinsic is likely to be
6355 incorrect or 0 for arguments other than zero, so it should only be used for
6356 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6357
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6358<p>Note that calling this intrinsic does not prevent function inlining or other
6359 aggressive transformations, so the value returned may not be that of the
6360 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6361
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6362</div>
6363
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6364<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6365<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6366 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6367</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6368
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6369<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6370
6371<h5>Syntax:</h5>
6372<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6373 declare i8* @llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6374</pre>
6375
6376<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6377<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6378 of the function stack, for use
6379 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6380 useful for implementing language features like scoped automatic variable
6381 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6382
6383<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6384<p>This intrinsic returns a opaque pointer value that can be passed
6385 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6386 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6387 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6388 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6389 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6390 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6391
6392</div>
6393
6394<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6395<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6396 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6397</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6398
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6399<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6400
6401<h5>Syntax:</h5>
6402<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6403 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6404</pre>
6405
6406<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6407<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6408 the function stack to the state it was in when the
6409 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6410 executed. This is useful for implementing language features like scoped
6411 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6412
6413<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6414<p>See the description
6415 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6416
6417</div>
6418
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6419<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6420<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6421 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6422</h4>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6423
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6424<div>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6425
6426<h5>Syntax:</h5>
6427<pre>
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6428 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;, i32 &lt;cache type&gt;)
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6429</pre>
6430
6431<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6432<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6433 insert a prefetch instruction if supported; otherwise, it is a noop.
6434 Prefetches have no effect on the behavior of the program but can change its
6435 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6436
6437<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6438<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6439 specifier determining if the fetch should be for a read (0) or write (1),
6440 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6441 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6442 specifies whether the prefetch is performed on the data (1) or instruction (0)
6443 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6444 must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6445
6446<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6447<p>This intrinsic does not modify the behavior of the program. In particular,
6448 prefetches cannot trap and do not produce a value. On targets that support
6449 this intrinsic, the prefetch can provide hints to the processor cache for
6450 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6451
6452</div>
6453
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6454<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6455<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6456 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6457</h4>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6458
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6459<div>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6460
6461<h5>Syntax:</h5>
6462<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6463 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6464</pre>
6465
6466<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6467<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6468 Counter (PC) in a region of code to simulators and other tools. The method
6469 is target specific, but it is expected that the marker will use exported
6470 symbols to transmit the PC of the marker. The marker makes no guarantees
6471 that it will remain with any specific instruction after optimizations. It is
6472 possible that the presence of a marker will inhibit optimizations. The
6473 intended use is to be inserted after optimizations to allow correlations of
6474 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6475
6476<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6477<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6478
6479<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6480<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6481 not support this intrinsic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6482
6483</div>
6484
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6485<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6486<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6487 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6488</h4>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6489
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6490<div>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6491
6492<h5>Syntax:</h5>
6493<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]6494 declare i64 @llvm.readcyclecounter()
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6495</pre>
6496
6497<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6498<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6499 counter register (or similar low latency, high accuracy clocks) on those
6500 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6501 should map to RPCC. As the backing counters overflow quickly (on the order
6502 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6503
6504<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6505<p>When directly supported, reading the cycle counter should not modify any
6506 memory. Implementations are allowed to either return a application specific
6507 value or a system wide value. On backends without support, this is lowered
6508 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6509
6510</div>
6511
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6512</div>
6513
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6514<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6515<h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6516 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6517</h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6518
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6519<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6520
6521<p>LLVM provides intrinsics for a few important standard C library functions.
6522 These intrinsics allow source-language front-ends to pass information about
6523 the alignment of the pointer arguments to the code generator, providing
6524 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6525
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6526<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6527<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6528 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6529</h4>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6530
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6531<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6532
6533<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6534<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
Mon P Wang508127b2010-04-07 06:35:53 +0000[diff] [blame]6535 integer bit width and for different address spaces. Not all targets support
6536 all bit widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6537
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6538<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6539 declare void @llvm.memcpy.p0i8.p0i8.i32(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6540 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6541 declare void @llvm.memcpy.p0i8.p0i8.i64(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6542 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6543</pre>
6544
6545<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6546<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6547 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6548
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6549<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6550 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6551 and the pointers can be in specified address spaces.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6552
6553<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6554
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6555<p>The first argument is a pointer to the destination, the second is a pointer
6556 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6557 number of bytes to copy, the fourth argument is the alignment of the
6558 source and destination locations, and the fifth is a boolean indicating a
6559 volatile access.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6560
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6561<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6562 then the caller guarantees that both the source and destination pointers are
6563 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6564
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6565<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6566 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6567 The detailed access behavior is not very cleanly specified and it is unwise
6568 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6569
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6570<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6571
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6572<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6573 source location to the destination location, which are not allowed to
6574 overlap. It copies "len" bytes of memory over. If the argument is known to
6575 be aligned to some boundary, this can be specified as the fourth argument,
6576 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6577
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6578</div>
6579
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6580<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6581<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6582 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6583</h4>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6584
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6585<div>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6586
6587<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6588<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Mon P Wang508127b2010-04-07 06:35:53 +0000[diff] [blame]6589 width and for different address space. Not all targets support all bit
6590 widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6591
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6592<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6593 declare void @llvm.memmove.p0i8.p0i8.i32(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6594 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6595 declare void @llvm.memmove.p0i8.p0i8.i64(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6596 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6597</pre>
6598
6599<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6600<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6601 source location to the destination location. It is similar to the
6602 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6603 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6604
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6605<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6606 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6607 and the pointers can be in specified address spaces.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6608
6609<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6610
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6611<p>The first argument is a pointer to the destination, the second is a pointer
6612 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6613 number of bytes to copy, the fourth argument is the alignment of the
6614 source and destination locations, and the fifth is a boolean indicating a
6615 volatile access.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6616
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6617<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6618 then the caller guarantees that the source and destination pointers are
6619 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6620
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6621<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6622 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6623 The detailed access behavior is not very cleanly specified and it is unwise
6624 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6625
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6626<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6627
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6628<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6629 source location to the destination location, which may overlap. It copies
6630 "len" bytes of memory over. If the argument is known to be aligned to some
6631 boundary, this can be specified as the fourth argument, otherwise it should
6632 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6633
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6634</div>
6635
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6636<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6637<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6638 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6639</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6640
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6641<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6642
6643<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6644<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6645 width and for different address spaces. However, not all targets support all
6646 bit widths.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6647
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6648<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6649 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6650 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6651 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6652 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6653</pre>
6654
6655<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6656<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6657 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6658
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6659<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6660 intrinsic does not return a value and takes extra alignment/volatile
6661 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6662
6663<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6664<p>The first argument is a pointer to the destination to fill, the second is the
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6665 byte value with which to fill it, the third argument is an integer argument
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6666 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6667 alignment of the destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6668
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6669<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6670 then the caller guarantees that the destination pointer is aligned to that
6671 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6672
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6673<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6674 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6675 The detailed access behavior is not very cleanly specified and it is unwise
6676 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6677
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6678<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6679<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6680 at the destination location. If the argument is known to be aligned to some
6681 boundary, this can be specified as the fourth argument, otherwise it should
6682 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6683
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6684</div>
6685
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6686<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6687<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6688 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6689</h4>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6690
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6691<div>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6692
6693<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6694<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6695 floating point or vector of floating point type. Not all targets support all
6696 types however.</p>
6697
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6698<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6699 declare float @llvm.sqrt.f32(float %Val)
6700 declare double @llvm.sqrt.f64(double %Val)
6701 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6702 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6703 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6704</pre>
6705
6706<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6707<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6708 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6709 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6710 behavior for negative numbers other than -0.0 (which allows for better
6711 optimization, because there is no need to worry about errno being
6712 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]6713
6714<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6715<p>The argument and return value are floating point numbers of the same
6716 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6717
6718<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6719<p>This function returns the sqrt of the specified operand if it is a
6720 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6721
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6722</div>
6723
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6724<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6725<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6726 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6727</h4>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6728
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6729<div>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6730
6731<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6732<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6733 floating point or vector of floating point type. Not all targets support all
6734 types however.</p>
6735
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6736<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6737 declare float @llvm.powi.f32(float %Val, i32 %power)
6738 declare double @llvm.powi.f64(double %Val, i32 %power)
6739 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6740 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6741 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6742</pre>
6743
6744<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6745<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6746 specified (positive or negative) power. The order of evaluation of
6747 multiplications is not defined. When a vector of floating point type is
6748 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6749
6750<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6751<p>The second argument is an integer power, and the first is a value to raise to
6752 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6753
6754<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6755<p>This function returns the first value raised to the second power with an
6756 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6757
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6758</div>
6759
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6760<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6761<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6762 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6763</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6764
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6765<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6766
6767<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6768<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6769 floating point or vector of floating point type. Not all targets support all
6770 types however.</p>
6771
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6772<pre>
6773 declare float @llvm.sin.f32(float %Val)
6774 declare double @llvm.sin.f64(double %Val)
6775 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6776 declare fp128 @llvm.sin.f128(fp128 %Val)
6777 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6778</pre>
6779
6780<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6781<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6782
6783<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6784<p>The argument and return value are floating point numbers of the same
6785 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6786
6787<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6788<p>This function returns the sine of the specified operand, returning the same
6789 values as the libm <tt>sin</tt> functions would, and handles error conditions
6790 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6791
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6792</div>
6793
6794<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6795<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6796 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6797</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6798
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6799<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6800
6801<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6802<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6803 floating point or vector of floating point type. Not all targets support all
6804 types however.</p>
6805
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6806<pre>
6807 declare float @llvm.cos.f32(float %Val)
6808 declare double @llvm.cos.f64(double %Val)
6809 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6810 declare fp128 @llvm.cos.f128(fp128 %Val)
6811 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6812</pre>
6813
6814<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6815<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6816
6817<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6818<p>The argument and return value are floating point numbers of the same
6819 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6820
6821<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6822<p>This function returns the cosine of the specified operand, returning the same
6823 values as the libm <tt>cos</tt> functions would, and handles error conditions
6824 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6825
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6826</div>
6827
6828<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6829<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6830 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6831</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6832
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6833<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6834
6835<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6836<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6837 floating point or vector of floating point type. Not all targets support all
6838 types however.</p>
6839
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6840<pre>
6841 declare float @llvm.pow.f32(float %Val, float %Power)
6842 declare double @llvm.pow.f64(double %Val, double %Power)
6843 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6844 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6845 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6846</pre>
6847
6848<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6849<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6850 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6851
6852<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6853<p>The second argument is a floating point power, and the first is a value to
6854 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6855
6856<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6857<p>This function returns the first value raised to the second power, returning
6858 the same values as the libm <tt>pow</tt> functions would, and handles error
6859 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6860
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6861</div>
6862
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6863</div>
6864
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6865<!-- _______________________________________________________________________ -->
6866<h4>
6867 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6868</h4>
6869
6870<div>
6871
6872<h5>Syntax:</h5>
6873<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6874 floating point or vector of floating point type. Not all targets support all
6875 types however.</p>
6876
6877<pre>
6878 declare float @llvm.exp.f32(float %Val)
6879 declare double @llvm.exp.f64(double %Val)
6880 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6881 declare fp128 @llvm.exp.f128(fp128 %Val)
6882 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6883</pre>
6884
6885<h5>Overview:</h5>
6886<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6887
6888<h5>Arguments:</h5>
6889<p>The argument and return value are floating point numbers of the same
6890 type.</p>
6891
6892<h5>Semantics:</h5>
6893<p>This function returns the same values as the libm <tt>exp</tt> functions
6894 would, and handles error conditions in the same way.</p>
6895
6896</div>
6897
6898<!-- _______________________________________________________________________ -->
6899<h4>
6900 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6901</h4>
6902
6903<div>
6904
6905<h5>Syntax:</h5>
6906<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6907 floating point or vector of floating point type. Not all targets support all
6908 types however.</p>
6909
6910<pre>
6911 declare float @llvm.log.f32(float %Val)
6912 declare double @llvm.log.f64(double %Val)
6913 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6914 declare fp128 @llvm.log.f128(fp128 %Val)
6915 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6916</pre>
6917
6918<h5>Overview:</h5>
6919<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6920
6921<h5>Arguments:</h5>
6922<p>The argument and return value are floating point numbers of the same
6923 type.</p>
6924
6925<h5>Semantics:</h5>
6926<p>This function returns the same values as the libm <tt>log</tt> functions
6927 would, and handles error conditions in the same way.</p>
6928
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]6929<h4>
6930 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
6931</h4>
6932
6933<div>
6934
6935<h5>Syntax:</h5>
6936<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
6937 floating point or vector of floating point type. Not all targets support all
6938 types however.</p>
6939
6940<pre>
6941 declare float @llvm.fma.f32(float %a, float %b, float %c)
6942 declare double @llvm.fma.f64(double %a, double %b, double %c)
6943 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
6944 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
6945 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
6946</pre>
6947
6948<h5>Overview:</h5>
Cameron Zwaricha32fd212011-07-08 22:13:55 +0000[diff] [blame]6949<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]6950 operation.</p>
6951
6952<h5>Arguments:</h5>
6953<p>The argument and return value are floating point numbers of the same
6954 type.</p>
6955
6956<h5>Semantics:</h5>
6957<p>This function returns the same values as the libm <tt>fma</tt> functions
6958 would.</p>
6959
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6960</div>
6961
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6962<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6963<h3>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6964 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6965</h3>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6966
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6967<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6968
6969<p>LLVM provides intrinsics for a few important bit manipulation operations.
6970 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6971
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6972<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6973<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6974 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6975</h4>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6976
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6977<div>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6978
6979<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6980<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6981 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6982
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6983<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6984 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6985 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6986 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6987</pre>
6988
6989<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6990<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6991 values with an even number of bytes (positive multiple of 16 bits). These
6992 are useful for performing operations on data that is not in the target's
6993 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6994
6995<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6996<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6997 and low byte of the input i16 swapped. Similarly,
6998 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6999 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
7000 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
7001 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
7002 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
7003 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]7004
7005</div>
7006
7007<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7008<h4>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]7009 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7010</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7011
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7012<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7013
7014<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]7015<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7016 width, or on any vector with integer elements. Not all targets support all
7017 bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7018
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7019<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7020 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7021 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]7022 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7023 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
7024 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7025 declare &lt;2 x i32&gt; @llvm.ctpop.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7026</pre>
7027
7028<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7029<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
7030 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7031
7032<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7033<p>The only argument is the value to be counted. The argument may be of any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7034 integer type, or a vector with integer elements.
7035 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7036
7037<h5>Semantics:</h5>
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7038<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
7039 element of a vector.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7040
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7041</div>
7042
7043<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7044<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]7045 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7046</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7047
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7048<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7049
7050<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7051<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7052 integer bit width, or any vector whose elements are integers. Not all
7053 targets support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7054
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7055<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7056 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
7057 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]7058 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7059 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
7060 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7061 declare &lt;2 x i32&gt; @llvm.ctlz.v2i32(&lt;2 x i32&gt; &lt;src;gt)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7062</pre>
7063
7064<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7065<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
7066 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7067
7068<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7069<p>The only argument is the value to be counted. The argument may be of any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7070 integer type, or any vector type with integer element type.
7071 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7072
7073<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7074<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7075 zeros in a variable, or within each element of the vector if the operation
7076 is of vector type. If the src == 0 then the result is the size in bits of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7077 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7078
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]7079</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]7080
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7081<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7082<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]7083 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7084</h4>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7085
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7086<div>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7087
7088<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7089<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7090 integer bit width, or any vector of integer elements. Not all targets
7091 support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7092
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7093<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7094 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
7095 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]7096 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]7097 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
7098 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7099 declase &lt;2 x i32&gt; @llvm.cttz.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7100</pre>
7101
7102<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7103<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
7104 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7105
7106<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7107<p>The only argument is the value to be counted. The argument may be of any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7108 integer type, or a vectory with integer element type.. The return type
7109 must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7110
7111<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7112<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]7113 zeros in a variable, or within each element of a vector.
7114 If the src == 0 then the result is the size in bits of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7115 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7116
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]7117</div>
7118
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7119</div>
7120
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7121<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7122<h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7123 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7124</h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7125
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7126<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7127
7128<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]7129
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7130<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7131<h4>
7132 <a name="int_sadd_overflow">
7133 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
7134 </a>
7135</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7136
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7137<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7138
7139<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7140<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]7141 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7142
7143<pre>
7144 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
7145 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7146 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
7147</pre>
7148
7149<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7150<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7151 a signed addition of the two arguments, and indicate whether an overflow
7152 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7153
7154<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7155<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]7156 be of integer types of any bit width, but they must have the same bit
7157 width. The second element of the result structure must be of
7158 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7159 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7160
7161<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7162<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7163 a signed addition of the two variables. They return a structure &mdash; the
7164 first element of which is the signed summation, and the second element of
7165 which is a bit specifying if the signed summation resulted in an
7166 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7167
7168<h5>Examples:</h5>
7169<pre>
7170 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7171 %sum = extractvalue {i32, i1} %res, 0
7172 %obit = extractvalue {i32, i1} %res, 1
7173 br i1 %obit, label %overflow, label %normal
7174</pre>
7175
7176</div>
7177
7178<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7179<h4>
7180 <a name="int_uadd_overflow">
7181 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
7182 </a>
7183</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7184
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7185<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7186
7187<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7188<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]7189 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7190
7191<pre>
7192 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
7193 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7194 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
7195</pre>
7196
7197<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7198<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7199 an unsigned addition of the two arguments, and indicate whether a carry
7200 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7201
7202<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7203<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]7204 be of integer types of any bit width, but they must have the same bit
7205 width. The second element of the result structure must be of
7206 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7207 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7208
7209<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7210<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7211 an unsigned addition of the two arguments. They return a structure &mdash;
7212 the first element of which is the sum, and the second element of which is a
7213 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7214
7215<h5>Examples:</h5>
7216<pre>
7217 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7218 %sum = extractvalue {i32, i1} %res, 0
7219 %obit = extractvalue {i32, i1} %res, 1
7220 br i1 %obit, label %carry, label %normal
7221</pre>
7222
7223</div>
7224
7225<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7226<h4>
7227 <a name="int_ssub_overflow">
7228 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
7229 </a>
7230</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7231
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7232<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7233
7234<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7235<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]7236 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7237
7238<pre>
7239 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
7240 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7241 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
7242</pre>
7243
7244<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7245<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7246 a signed subtraction of the two arguments, and indicate whether an overflow
7247 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7248
7249<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7250<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]7251 be of integer types of any bit width, but they must have the same bit
7252 width. The second element of the result structure must be of
7253 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7254 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7255
7256<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7257<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7258 a signed subtraction of the two arguments. They return a structure &mdash;
7259 the first element of which is the subtraction, and the second element of
7260 which is a bit specifying if the signed subtraction resulted in an
7261 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7262
7263<h5>Examples:</h5>
7264<pre>
7265 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7266 %sum = extractvalue {i32, i1} %res, 0
7267 %obit = extractvalue {i32, i1} %res, 1
7268 br i1 %obit, label %overflow, label %normal
7269</pre>
7270
7271</div>
7272
7273<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7274<h4>
7275 <a name="int_usub_overflow">
7276 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
7277 </a>
7278</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7279
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7280<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7281
7282<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7283<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]7284 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7285
7286<pre>
7287 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
7288 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7289 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
7290</pre>
7291
7292<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7293<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7294 an unsigned subtraction of the two arguments, and indicate whether an
7295 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7296
7297<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7298<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]7299 be of integer types of any bit width, but they must have the same bit
7300 width. The second element of the result structure must be of
7301 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7302 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7303
7304<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7305<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7306 an unsigned subtraction of the two arguments. They return a structure &mdash;
7307 the first element of which is the subtraction, and the second element of
7308 which is a bit specifying if the unsigned subtraction resulted in an
7309 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7310
7311<h5>Examples:</h5>
7312<pre>
7313 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7314 %sum = extractvalue {i32, i1} %res, 0
7315 %obit = extractvalue {i32, i1} %res, 1
7316 br i1 %obit, label %overflow, label %normal
7317</pre>
7318
7319</div>
7320
7321<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7322<h4>
7323 <a name="int_smul_overflow">
7324 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
7325 </a>
7326</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7327
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7328<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7329
7330<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7331<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]7332 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7333
7334<pre>
7335 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
7336 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7337 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
7338</pre>
7339
7340<h5>Overview:</h5>
7341
7342<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7343 a signed multiplication of the two arguments, and indicate whether an
7344 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7345
7346<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7347<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]7348 be of integer types of any bit width, but they must have the same bit
7349 width. The second element of the result structure must be of
7350 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7351 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7352
7353<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7354<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7355 a signed multiplication of the two arguments. They return a structure &mdash;
7356 the first element of which is the multiplication, and the second element of
7357 which is a bit specifying if the signed multiplication resulted in an
7358 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7359
7360<h5>Examples:</h5>
7361<pre>
7362 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7363 %sum = extractvalue {i32, i1} %res, 0
7364 %obit = extractvalue {i32, i1} %res, 1
7365 br i1 %obit, label %overflow, label %normal
7366</pre>
7367
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]7368</div>
7369
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7370<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7371<h4>
7372 <a name="int_umul_overflow">
7373 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7374 </a>
7375</h4>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7376
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7377<div>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7378
7379<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7380<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]7381 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7382
7383<pre>
7384 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7385 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7386 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7387</pre>
7388
7389<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7390<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7391 a unsigned multiplication of the two arguments, and indicate whether an
7392 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7393
7394<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7395<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]7396 be of integer types of any bit width, but they must have the same bit
7397 width. The second element of the result structure must be of
7398 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7399 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7400
7401<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7402<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7403 an unsigned multiplication of the two arguments. They return a structure
7404 &mdash; the first element of which is the multiplication, and the second
7405 element of which is a bit specifying if the unsigned multiplication resulted
7406 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7407
7408<h5>Examples:</h5>
7409<pre>
7410 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7411 %sum = extractvalue {i32, i1} %res, 0
7412 %obit = extractvalue {i32, i1} %res, 1
7413 br i1 %obit, label %overflow, label %normal
7414</pre>
7415
7416</div>
7417
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7418</div>
7419
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7420<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7421<h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7422 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7423</h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7424
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7425<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7426
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7427<p>Half precision floating point is a storage-only format. This means that it is
7428 a dense encoding (in memory) but does not support computation in the
7429 format.</p>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7430
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7431<p>This means that code must first load the half-precision floating point
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7432 value as an i16, then convert it to float with <a
7433 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7434 Computation can then be performed on the float value (including extending to
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7435 double etc). To store the value back to memory, it is first converted to
7436 float if needed, then converted to i16 with
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7437 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7438 storing as an i16 value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7439
7440<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7441<h4>
7442 <a name="int_convert_to_fp16">
7443 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7444 </a>
7445</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7446
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7447<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7448
7449<h5>Syntax:</h5>
7450<pre>
7451 declare i16 @llvm.convert.to.fp16(f32 %a)
7452</pre>
7453
7454<h5>Overview:</h5>
7455<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7456 a conversion from single precision floating point format to half precision
7457 floating point format.</p>
7458
7459<h5>Arguments:</h5>
7460<p>The intrinsic function contains single argument - the value to be
7461 converted.</p>
7462
7463<h5>Semantics:</h5>
7464<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7465 a conversion from single precision floating point format to half precision
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7466 floating point format. The return value is an <tt>i16</tt> which
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7467 contains the converted number.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7468
7469<h5>Examples:</h5>
7470<pre>
7471 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7472 store i16 %res, i16* @x, align 2
7473</pre>
7474
7475</div>
7476
7477<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7478<h4>
7479 <a name="int_convert_from_fp16">
7480 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7481 </a>
7482</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7483
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7484<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7485
7486<h5>Syntax:</h5>
7487<pre>
7488 declare f32 @llvm.convert.from.fp16(i16 %a)
7489</pre>
7490
7491<h5>Overview:</h5>
7492<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7493 a conversion from half precision floating point format to single precision
7494 floating point format.</p>
7495
7496<h5>Arguments:</h5>
7497<p>The intrinsic function contains single argument - the value to be
7498 converted.</p>
7499
7500<h5>Semantics:</h5>
7501<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7502 conversion from half single precision floating point format to single
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7503 precision floating point format. The input half-float value is represented by
7504 an <tt>i16</tt> value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7505
7506<h5>Examples:</h5>
7507<pre>
7508 %a = load i16* @x, align 2
7509 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7510</pre>
7511
7512</div>
7513
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7514</div>
7515
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7516<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7517<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7518 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7519</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7520
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7521<div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7522
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7523<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7524 prefix), are described in
7525 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7526 Level Debugging</a> document.</p>
7527
7528</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7529
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7530<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7531<h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7532 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7533</h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7534
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7535<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7536
7537<p>The LLVM exception handling intrinsics (which all start with
7538 <tt>llvm.eh.</tt> prefix), are described in
7539 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7540 Handling</a> document.</p>
7541
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7542</div>
7543
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7544<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7545<h3>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7546 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7547</h3>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7548
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7549<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7550
7551<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]7552 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7553 The result is a callable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7554 function pointer lacking the nest parameter - the caller does not need to
7555 provide a value for it. Instead, the value to use is stored in advance in a
7556 "trampoline", a block of memory usually allocated on the stack, which also
7557 contains code to splice the nest value into the argument list. This is used
7558 to implement the GCC nested function address extension.</p>
7559
7560<p>For example, if the function is
7561 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7562 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7563 follows:</p>
7564
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]7565<pre class="doc_code">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7566 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7567 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7568 %p = call i8* @llvm.init.trampoline(i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval)
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7569 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7570</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7571
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7572<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7573 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7574
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7575<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7576<h4>
7577 <a name="int_it">
7578 '<tt>llvm.init.trampoline</tt>' Intrinsic
7579 </a>
7580</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7581
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7582<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7583
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7584<h5>Syntax:</h5>
7585<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7586 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]7587</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7588
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7589<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7590<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7591 function pointer suitable for executing it.</p>
7592
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7593<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7594<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7595 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7596 sufficiently aligned block of memory; this memory is written to by the
7597 intrinsic. Note that the size and the alignment are target-specific - LLVM
7598 currently provides no portable way of determining them, so a front-end that
7599 generates this intrinsic needs to have some target-specific knowledge.
7600 The <tt>func</tt> argument must hold a function bitcast to
7601 an <tt>i8*</tt>.</p>
7602
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7603<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7604<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7605 dependent code, turning it into a function. A pointer to this function is
7606 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7607 function pointer type</a> before being called. The new function's signature
7608 is the same as that of <tt>func</tt> with any arguments marked with
7609 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7610 is allowed, and it must be of pointer type. Calling the new function is
7611 equivalent to calling <tt>func</tt> with the same argument list, but
7612 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7613 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7614 by <tt>tramp</tt> is modified, then the effect of any later call to the
7615 returned function pointer is undefined.</p>
7616
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7617</div>
7618
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7619</div>
7620
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7621<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7622<h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7623 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7624</h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7625
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7626<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7627
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7628<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7629 hardware constructs for atomic operations and memory synchronization. This
7630 provides an interface to the hardware, not an interface to the programmer. It
7631 is aimed at a low enough level to allow any programming models or APIs
7632 (Application Programming Interfaces) which need atomic behaviors to map
7633 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7634 hardware provides a "universal IR" for source languages, it also provides a
7635 starting point for developing a "universal" atomic operation and
7636 synchronization IR.</p>
7637
7638<p>These do <em>not</em> form an API such as high-level threading libraries,
7639 software transaction memory systems, atomic primitives, and intrinsic
7640 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7641 application libraries. The hardware interface provided by LLVM should allow
7642 a clean implementation of all of these APIs and parallel programming models.
7643 No one model or paradigm should be selected above others unless the hardware
7644 itself ubiquitously does so.</p>
7645
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7646<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7647<h4>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7648 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7649</h4>
7650
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7651<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7652<h5>Syntax:</h5>
7653<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7654 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]7655</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7656
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7657<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7658<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7659 specific pairs of memory access types.</p>
7660
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7661<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7662<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7663 The first four arguments enables a specific barrier as listed below. The
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]7664 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7665 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7666
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7667<ul>
7668 <li><tt>ll</tt>: load-load barrier</li>
7669 <li><tt>ls</tt>: load-store barrier</li>
7670 <li><tt>sl</tt>: store-load barrier</li>
7671 <li><tt>ss</tt>: store-store barrier</li>
7672 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7673</ul>
7674
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7675<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7676<p>This intrinsic causes the system to enforce some ordering constraints upon
7677 the loads and stores of the program. This barrier does not
7678 indicate <em>when</em> any events will occur, it only enforces
7679 an <em>order</em> in which they occur. For any of the specified pairs of load
7680 and store operations (f.ex. load-load, or store-load), all of the first
7681 operations preceding the barrier will complete before any of the second
7682 operations succeeding the barrier begin. Specifically the semantics for each
7683 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7684
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7685<ul>
7686 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7687 after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7688 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7689 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7690 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7691 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7692 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7693 load after the barrier begins.</li>
7694</ul>
7695
7696<p>These semantics are applied with a logical "and" behavior when more than one
7697 is enabled in a single memory barrier intrinsic.</p>
7698
7699<p>Backends may implement stronger barriers than those requested when they do
7700 not support as fine grained a barrier as requested. Some architectures do
7701 not need all types of barriers and on such architectures, these become
7702 noops.</p>
7703
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7704<h5>Example:</h5>
7705<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7706%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7707%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7708 store i32 4, %ptr
7709
7710%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0ac49c62011-06-29 17:14:00 +0000[diff] [blame]7711 call void @llvm.memory.barrier(i1 false, i1 true, i1 false, i1 false, i1 true)
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7712 <i>; guarantee the above finishes</i>
7713 store i32 8, %ptr <i>; before this begins</i>
7714</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7715
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7716</div>
7717
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7718<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7719<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7720 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7721</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7722
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7723<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7724
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7725<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7726<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7727 any integer bit width and for different address spaces. Not all targets
7728 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7729
7730<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7731 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7732 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7733 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7734 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]7735</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7736
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7737<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7738<p>This loads a value in memory and compares it to a given value. If they are
7739 equal, it stores a new value into the memory.</p>
7740
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7741<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7742<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7743 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7744 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7745 this integer type. While any bit width integer may be used, targets may only
7746 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7747
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7748<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7749<p>This entire intrinsic must be executed atomically. It first loads the value
7750 in memory pointed to by <tt>ptr</tt> and compares it with the
7751 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7752 memory. The loaded value is yielded in all cases. This provides the
7753 equivalent of an atomic compare-and-swap operation within the SSA
7754 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7755
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7756<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7757<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7758%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7759%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7760 store i32 4, %ptr
7761
7762%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7763%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7764 <i>; yields {i32}:result1 = 4</i>
7765%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7766%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7767
7768%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7769%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7770 <i>; yields {i32}:result2 = 8</i>
7771%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7772
7773%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7774</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7775
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7776</div>
7777
7778<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7779<h4>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7780 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7781</h4>
7782
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7783<div>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7784<h5>Syntax:</h5>
7785
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7786<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7787 integer bit width. Not all targets support all bit widths however.</p>
7788
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7789<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7790 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7791 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7792 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7793 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]7794</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7795
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7796<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7797<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7798 the value from memory. It then stores the value in <tt>val</tt> in the memory
7799 at <tt>ptr</tt>.</p>
7800
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7801<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7802<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7803 the <tt>val</tt> argument and the result must be integers of the same bit
7804 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7805 integer type. The targets may only lower integer representations they
7806 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7807
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7808<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7809<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7810 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7811 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7812
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7813<h5>Examples:</h5>
7814<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7815%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7816%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7817 store i32 4, %ptr
7818
7819%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7820%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7821 <i>; yields {i32}:result1 = 4</i>
7822%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7823%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7824
7825%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7826%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7827 <i>; yields {i32}:result2 = 8</i>
7828
7829%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7830%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7831</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7832
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7833</div>
7834
7835<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7836<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7837 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7838</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7839
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7840<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7841
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7842<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7843<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7844 any integer bit width. Not all targets support all bit widths however.</p>
7845
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7846<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7847 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7848 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7849 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7850 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]7851</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7852
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7853<h5>Overview:</h5>
7854<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7855 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7856
7857<h5>Arguments:</h5>
7858<p>The intrinsic takes two arguments, the first a pointer to an integer value
7859 and the second an integer value. The result is also an integer value. These
7860 integer types can have any bit width, but they must all have the same bit
7861 width. The targets may only lower integer representations they support.</p>
7862
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7863<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7864<p>This intrinsic does a series of operations atomically. It first loads the
7865 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7866 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]7867
7868<h5>Examples:</h5>
7869<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7870%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7871%ptr = bitcast i8* %mallocP to i32*
7872 store i32 4, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7873%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7874 <i>; yields {i32}:result1 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7875%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7876 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7877%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7878 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7879%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7880</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7881
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7882</div>
7883
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7884<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7885<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7886 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7887</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7888
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7889<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7890
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7891<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7892<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7893 any integer bit width and for different address spaces. Not all targets
7894 support all bit widths however.</p>
7895
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7896<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7897 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7898 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7899 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7900 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]7901</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7902
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7903<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7904<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7905 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7906
7907<h5>Arguments:</h5>
7908<p>The intrinsic takes two arguments, the first a pointer to an integer value
7909 and the second an integer value. The result is also an integer value. These
7910 integer types can have any bit width, but they must all have the same bit
7911 width. The targets may only lower integer representations they support.</p>
7912
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7913<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7914<p>This intrinsic does a series of operations atomically. It first loads the
7915 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7916 result to <tt>ptr</tt>. It yields the original value stored
7917 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7918
7919<h5>Examples:</h5>
7920<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7921%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7922%ptr = bitcast i8* %mallocP to i32*
7923 store i32 8, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7924%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7925 <i>; yields {i32}:result1 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7926%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7927 <i>; yields {i32}:result2 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7928%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7929 <i>; yields {i32}:result3 = 2</i>
7930%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7931</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7932
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7933</div>
7934
7935<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7936<h4>
7937 <a name="int_atomic_load_and">
7938 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7939 </a>
7940 <br>
7941 <a name="int_atomic_load_nand">
7942 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7943 </a>
7944 <br>
7945 <a name="int_atomic_load_or">
7946 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7947 </a>
7948 <br>
7949 <a name="int_atomic_load_xor">
7950 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7951 </a>
7952</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7953
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7954<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7955
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7956<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7957<p>These are overloaded intrinsics. You can
7958 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7959 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7960 bit width and for different address spaces. Not all targets support all bit
7961 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7962
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7963<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7964 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7965 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7966 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7967 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]7968</pre>
7969
7970<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7971 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7972 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7973 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7974 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]7975</pre>
7976
7977<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7978 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7979 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7980 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7981 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]7982</pre>
7983
7984<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7985 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7986 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7987 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7988 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]7989</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7990
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7991<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7992<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7993 the value stored in memory at <tt>ptr</tt>. It yields the original value
7994 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7995
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7996<h5>Arguments:</h5>
7997<p>These intrinsics take two arguments, the first a pointer to an integer value
7998 and the second an integer value. The result is also an integer value. These
7999 integer types can have any bit width, but they must all have the same bit
8000 width. The targets may only lower integer representations they support.</p>
8001
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8002<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8003<p>These intrinsics does a series of operations atomically. They first load the
8004 value stored at <tt>ptr</tt>. They then do the bitwise
8005 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
8006 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8007
8008<h5>Examples:</h5>
8009<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]8010%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8011%ptr = bitcast i8* %mallocP to i32*
8012 store i32 0x0F0F, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8013%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8014 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8015%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8016 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8017%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8018 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8019%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8020 <i>; yields {i32}:result3 = FF</i>
8021%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
8022</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8023
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8024</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8025
8026<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8027<h4>
8028 <a name="int_atomic_load_max">
8029 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
8030 </a>
8031 <br>
8032 <a name="int_atomic_load_min">
8033 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
8034 </a>
8035 <br>
8036 <a name="int_atomic_load_umax">
8037 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
8038 </a>
8039 <br>
8040 <a name="int_atomic_load_umin">
8041 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
8042 </a>
8043</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8044
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8045<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8046
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8047<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8048<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
8049 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
8050 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
8051 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8052
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8053<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8054 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8055 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8056 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8057 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]8058</pre>
8059
8060<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8061 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8062 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8063 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8064 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]8065</pre>
8066
8067<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8068 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8069 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8070 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8071 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]8072</pre>
8073
8074<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8075 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8076 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8077 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8078 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]8079</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8080
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8081<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]8082<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8083 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
8084 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8085
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8086<h5>Arguments:</h5>
8087<p>These intrinsics take two arguments, the first a pointer to an integer value
8088 and the second an integer value. The result is also an integer value. These
8089 integer types can have any bit width, but they must all have the same bit
8090 width. The targets may only lower integer representations they support.</p>
8091
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8092<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8093<p>These intrinsics does a series of operations atomically. They first load the
8094 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
8095 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
8096 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8097
8098<h5>Examples:</h5>
8099<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]8100%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8101%ptr = bitcast i8* %mallocP to i32*
8102 store i32 7, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8103%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8104 <i>; yields {i32}:result0 = 7</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8105%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8106 <i>; yields {i32}:result1 = -2</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8107%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8108 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8109%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8110 <i>; yields {i32}:result3 = 8</i>
8111%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
8112</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8113
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]8114</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]8115
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8116</div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8117
8118<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8119<h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8120 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8121</h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8122
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8123<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8124
8125<p>This class of intrinsics exists to information about the lifetime of memory
8126 objects and ranges where variables are immutable.</p>
8127
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8128<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8129<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8130 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8131</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8132
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8133<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8134
8135<h5>Syntax:</h5>
8136<pre>
8137 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8138</pre>
8139
8140<h5>Overview:</h5>
8141<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
8142 object's lifetime.</p>
8143
8144<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8145<p>The first argument is a constant integer representing the size of the
8146 object, or -1 if it is variable sized. The second argument is a pointer to
8147 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8148
8149<h5>Semantics:</h5>
8150<p>This intrinsic indicates that before this point in the code, the value of the
8151 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
Nick Lewyckyd20fd592009-10-27 16:56:58 +0000[diff] [blame]8152 never be used and has an undefined value. A load from the pointer that
8153 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8154 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
8155
8156</div>
8157
8158<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8159<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8160 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8161</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8162
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8163<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8164
8165<h5>Syntax:</h5>
8166<pre>
8167 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8168</pre>
8169
8170<h5>Overview:</h5>
8171<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
8172 object's lifetime.</p>
8173
8174<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8175<p>The first argument is a constant integer representing the size of the
8176 object, or -1 if it is variable sized. The second argument is a pointer to
8177 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8178
8179<h5>Semantics:</h5>
8180<p>This intrinsic indicates that after this point in the code, the value of the
8181 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
8182 never be used and has an undefined value. Any stores into the memory object
8183 following this intrinsic may be removed as dead.
8184
8185</div>
8186
8187<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8188<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8189 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8190</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8191
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8192<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8193
8194<h5>Syntax:</h5>
8195<pre>
Nick Lewycky2965d3e2010-11-30 04:13:41 +0000[diff] [blame]8196 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8197</pre>
8198
8199<h5>Overview:</h5>
8200<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
8201 a memory object will not change.</p>
8202
8203<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8204<p>The first argument is a constant integer representing the size of the
8205 object, or -1 if it is variable sized. The second argument is a pointer to
8206 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8207
8208<h5>Semantics:</h5>
8209<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
8210 the return value, the referenced memory location is constant and
8211 unchanging.</p>
8212
8213</div>
8214
8215<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8216<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8217 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8218</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8219
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8220<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8221
8222<h5>Syntax:</h5>
8223<pre>
8224 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8225</pre>
8226
8227<h5>Overview:</h5>
8228<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
8229 a memory object are mutable.</p>
8230
8231<h5>Arguments:</h5>
8232<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]8233 The second argument is a constant integer representing the size of the
8234 object, or -1 if it is variable sized and the third argument is a pointer
8235 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]8236
8237<h5>Semantics:</h5>
8238<p>This intrinsic indicates that the memory is mutable again.</p>
8239
8240</div>
8241
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8242</div>
8243
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]8244<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8245<h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8246 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8247</h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8248
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8249<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8250
8251<p>This class of intrinsics is designed to be generic and has no specific
8252 purpose.</p>
8253
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8254<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8255<h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8256 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8257</h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8258
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8259<div>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8260
8261<h5>Syntax:</h5>
8262<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8263 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]8264</pre>
8265
8266<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8267<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8268
8269<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8270<p>The first argument is a pointer to a value, the second is a pointer to a
8271 global string, the third is a pointer to a global string which is the source
8272 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8273
8274<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8275<p>This intrinsic allows annotation of local variables with arbitrary strings.
8276 This can be useful for special purpose optimizations that want to look for
8277 these annotations. These have no other defined use, they are ignored by code
8278 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8279
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]8280</div>
8281
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8282<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8283<h4>
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]8284 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8285</h4>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8286
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8287<div>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8288
8289<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8290<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
8291 any integer bit width.</p>
8292
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8293<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8294 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8295 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8296 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8297 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8298 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]8299</pre>
8300
8301<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8302<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8303
8304<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8305<p>The first argument is an integer value (result of some expression), the
8306 second is a pointer to a global string, the third is a pointer to a global
8307 string which is the source file name, and the last argument is the line
8308 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8309
8310<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8311<p>This intrinsic allows annotations to be put on arbitrary expressions with
8312 arbitrary strings. This can be useful for special purpose optimizations that
8313 want to look for these annotations. These have no other defined use, they
8314 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8315
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]8316</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]8317
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8318<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8319<h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8320 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8321</h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8322
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8323<div>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8324
8325<h5>Syntax:</h5>
8326<pre>
8327 declare void @llvm.trap()
8328</pre>
8329
8330<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8331<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8332
8333<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8334<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8335
8336<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8337<p>This intrinsics is lowered to the target dependent trap instruction. If the
8338 target does not have a trap instruction, this intrinsic will be lowered to
8339 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8340
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]8341</div>
8342
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8343<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8344<h4>
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]8345 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8346</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8347
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8348<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8349
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8350<h5>Syntax:</h5>
8351<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8352 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8353</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8354
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8355<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8356<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8357 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8358 ensure that it is placed on the stack before local variables.</p>
8359
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8360<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8361<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8362 arguments. The first argument is the value loaded from the stack
8363 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8364 that has enough space to hold the value of the guard.</p>
8365
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8366<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8367<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8368 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8369 stack. This is to ensure that if a local variable on the stack is
8370 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8371 the guard on the stack is checked against the original guard. If they are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8372 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8373 function.</p>
8374
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8375</div>
8376
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8377<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8378<h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8379 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8380</h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8381
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8382<div>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8383
8384<h5>Syntax:</h5>
8385<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8386 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8387 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8388</pre>
8389
8390<h5>Overview:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8391<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8392 the optimizers to determine at compile time whether a) an operation (like
8393 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8394 runtime check for overflow isn't necessary. An object in this context means
8395 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8396
8397<h5>Arguments:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8398<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]8399 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8400 is a boolean 0 or 1. This argument determines whether you want the
8401 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]8402 1, variables are not allowed.</p>
8403
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8404<h5>Semantics:</h5>
8405<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8406 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8407 depending on the <tt>type</tt> argument, if the size cannot be determined at
8408 compile time.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8409
8410</div>
8411
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8412</div>
8413
8414</div>
8415
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8416<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8417<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8418<address>
8419 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8420 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8421 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8422 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]8423
8424 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]8425 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8426 Last modified: $Date$
8427</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]8428
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]8429</body>
8430</html>